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Arthropods Vs YEC
Coral Vs YEC
Egyptology Vs YEC
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Humans Are Apes Period
Iridium And Impact Vs YEC
Limestone Vs YEC
Mammalian Ear Evolution
Mass Extinctions Vs YEC
Radiometric Dating And Plate Tectonics
Radiometric Dating Vs YEC
The Laetoli Footprints Vs AiG
Transitional Species: Basal Ape To Human
Transitional Species: Dinosaurs To Birds
Transitional Species: Fish To Tetrapods
Transitional Species: Land Mammals To Cetaceans

Who Made the Laetoli Footprints? A Look at the Consensus, And the Dissenters (Answers in Genesis Primarily)

7/27/2019

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3.7 million years ago a small band of hominids were making their way across Laetoli, Tanzania when they happened to have the misfortune of being caught in the aftermath of a nearby volcanic eruption. The troop was small, with two assured individuals and a potential two more, and as they lumbered across the terrain's fresh ashfall, they left deep footprints behind to catalog their journey.  The smaller tracks are identified as the female of the two and was perhaps burdened with carrying a child on her hip according to the weight distribution and the male's tracks have what appear to be juvenile tracks within them, as if a youngster was following within their parent's footsteps close behind. 

These tracks were discovered in 1976 by the venerable Mary Leakey, and at the time they were considered the first evidence of assured bipedality in a hominin. Of course, many specimens of earlier species now deemed at least primarily bipedal have now been found (such as A. ramidus and perhaps even S. tchadensis) due to their incredibly well-preserved skeletons.

Since then, Creationists of many kinds have attempted to discredit the tracks, claiming they are certainly human (or within human variability) and that the "chimp-like" A. afarensis could never have made such remarkable trace fossils. 

In the following post, we will examine the Laetoli Footprints in detail, along with the anatomical requirements for bipedality, the specimens of A. afarensis in the fossil record and the specific dissent of YEC organization Answers in Genesis. 

Shall we, my fellow hominids?

Part 1: A Basic Rundown of the Laetoli Site

The Laetoli Tracks consist of 75 foot line of foot imprints in a layer of hardened ash located in Laetoli, Tanzania. 

The tracks themselves are best preserved in the steps of the two primary individuals, whose stride appears to be 47 cm (Male) and 28 cm (Female) in length. The dimensions are 21. 5 cm long and 10 cm wide (Male) and 18.5 cm long, and 8.8 wide  (Female). As such, sexual dimorphism appears to be present in the foot size, although the stride is perhaps partially due to the female's burdened gait favoring one side. 

There are no knuckle impressions whatsoever accompanying the prints, and the feet lack a fully divergent big toe (trademark for the great apes). Furthermore, the foot arch on all visible tracks is nearly akin to a modern human, and thus also all of genus homo. 

Even back in the 70's these tracks were tentatively attributed to Australopithecus afarensis by Mary Leaky and her team, as the most complete specimen (nicknamed "Lucy") had only just been discovered and the initial analysis seemed to support the tracks had been made around the time that Lucy had died.  

This was further supported by an analysis of nearby fauna tracks also made in the ash, which included those of Hipparion (a three-toed basal equid) and Deinotherium, whose remains had been found in the vicinity of Lucy Northward. 

Now, we can certainly make arguments that radiometric dating confirms (to a near-definitive point) that these tracks were made by the most common hominin in the area at the time: A. afarensis. This will be commonly ignored by Young Earth Creationists though, as they do not trust the nature of radiometric dating and find teh tracks to be "too human" to be attributed to what they consider a "pure ape". 

For this reason, we will stick exclusively to analyzing the anatomy of A. afarensis and the physical characteristics of the tracks in order to answer two very important questions: 

1: Could the tracks have been mechanically produced by a modern human? 
2: If not, could Australopithecus afarensis have made them?

We already know the local fauna support that A. afarensis made these tracks, but typically this is also not good enough for YECs as they propose all animals (including humans) lived at one time prior to the Global Flood. This means it is of no consequence to them that Hipparion was milling about alongside these tracks. 

So let us instead move to look at conventional anthropology's Person of Interest in depth.

Part 2:  The Art of Bipedalism

Bipedality is a tricky game. As far as locomotion goes, the safer bet is certainly to distribute weight on four available limbs rather than balancing on two. However, for an organism with forelimbs that can serve a more versatile purpose it is a worthy trade. 

All modern birds locomote on two hind legs. This frees up the wings for flight, thermoregulation, water propulsion, sexual display and defense. 

In more basal primates, while forelimbs may be used to move about quadrepedally through the trees or bear weight on the knuckles terrestrially, they also serve to strengthen social bonds through grooming and manipulate objects and materials for nest building or even tool use. 

But in the hominids our free arms allow us to move and use tools at the same time, as well as carry our belongings around or bring food back to a home base. 

Furthermore, standing on our hind limbs gives us an incredible vantage point to spot both our predators and our prey. 

But what actually makes a primate a biped? What anatomically must be present in order to move about on two back limbs in an efficient and "worthwhile" manner? 

There are generally four big skeletal changes that must occur before muscle attachments can maximize efficiency. Your basic primate biped MUST have some degree of the following:
  1. Location of the foremen magnum opening in the skull
  2. Valgus knee presence, or the “carrying angle”
  3. Halux (big toe) is in-line with the rest of the toes
  4. Pelvic structure
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Location of the Foremen Magnum: The foremen magnum is the opening at the base of the skull that allows the spinal cord to pass from the brain to the rest of the body. In bipedal animals such as humans or birds, the foremen magnum is directly ventral, or underneath, the skull. In animals that are primarily or partially quadrupedal, the opening is more dorsal.
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Australopithecus afarensis is directly intermediate from a chimpanzee and a human, the former of which are habitual bipeds and the latter of which are obligate bipeds. (pictured below is the Dikika Child, ventral view)
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 The Valgus Knee, or "Carrying Angle": The valgus knee is responsible for placing the maximum center of gravity below the body directly in order to make locomotion efficient. This also reduces the body surface area exposed to direct sunlight, potentially having thermoregulation benefits. Humans and all hominids we have record of, including the most primitive Sahelanthropus tchadensis, possess this knee. 

Pictured below to the Left: A. afarensis knee (patella missing), Right: Human knee
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Hallux (big toe) in-line with rest of toes: The hallux is vital for human push off and balance when we walk. In chimpanzees, they cannot walk bipedally for long periods in part due to their inefficient movement thanks to awkward push offs. A. afarensis has a foot and toe structure FAR more in line with modern humans than chimps. Specimens of Australopithecus Feet Below: Left and Below: Dikika Child,  Right: Lucy,  Above: Little Foot
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Hip Structure: Flared blades indicates attachment sites for muscle that are similar to that of genus homo, more so than that of the great apes. Bowl-Shape allows for a strong pelvic floor, absolutely necessary for bipedal walking. 

To summarize quite simply: all the requirements that are necessary for modern humans to remain upright and walk are ALSO found on A. afarensis, albeit to "less efficient" degrees. 

What this says definitively is this: Australopithecus afarensis certainly COULD HAVE made those prints based on it's ability to walk upright, and general foot shape. But now we must ask our first question once more: 

Could a human have made the Laetoli footprints, mechanically speaking? 

If so, the Laetoli Footprints are inconsequential to Young Earth Creationists. A human could have made them, and the connections the prints have to a nearby hominid don't really matter. 

But, if not, then we have a new issue. We have an animal that made prints so close to that of modern humans it fooled an entire denomination. We have an animal, that from the waist down, is very nearly a member of our genus. But from her beltline up, she is a "Pure Ape", from her prognathism, canines and browridge to her abysmal braincase. 

We have the "ape-man" (or "ape-woman" in Lucy's case) that Answers in Genesis is always crowing for. 

Fortunately, a very curious bunch decided to test the dimensions, gait, stride and weight distribution of the tracks against those of both modern humans and chimpanzees (common). 

So, what did THEY find?
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Part 3: The Royal Society and the Laetoli Footprints

This portion will contain quite a bit of pasted material from the paper, which was published in 2016, and can be found here.

The title says it all: "Laetoli footprints reveal bipedal gait biomechanics different from those of modern humans and chimpanzees"

The experiment gathered data on modern human locomotion, chimpanzee locomotion and the Laetoli footprints. They then compared the data sets. 

The methods are as follows: 

Human Collection (performed in soil closest in grain size to the Laetoli Ashfall)

"The experiments that produced the human comparative dataset were conducted in the field at Ileret, Kenya, with 41 habitually barefoot and minimally shod modern humans (15 adult males, 14 adult females, 10 juvenile males, 2 juvenile females) producing a total of 490 footprints, of which 245 were used in this analysis (see below)...I n each trial, videos were recorded in a lateral view, and these were later digitized for two-dimensional kinematic analysis. The footprints produced in each trial were photographed, with scale, from a variety of angles and orientations such that high-resolution, scaled three-dimensional models could be rendered using photogrammetry software"

Chimpanzee Collection

"A set of experiments analogous to the human footprint experiments were performed with two chimpanzees in the Primate Locomotion Laboratory at Stony Brook University, in accordance with the policies of the Stony Brook University Institutional Animal Care and Use Committee. Chimpanzees were trained through positive reinforcement to walk bipedally at their preferred speeds across a trackway containing a sample of the same sediment used in the human experiments. Substrate conditions (compaction and hydration levels) were adjusted such that the chimpanzees produced footprints of similar depths to those created in the human experiments, which were in turn similar to the Laetoli prints."

Laetoli Collection (Superimposed Prints from G2 trackway excluded)

"Because the Laetoli hominin footprints remain buried for conservation purposes, all data were collected from first-generation casts prepared during the site's initial excavation [
25] and currently stored at the National Museums of Kenya. Casts of every footprint were not available, but they were available for many of the better-preserved prints from the southern portions of the footprint trackways [26]. The morphology of each was quantified following the same procedure as for the experimentally produced footprints."

Analysis (in depth and figures can be found in paper) and Conclusion

“The Laetoli footprints, which are morphologically distinct from those of modern humans (figure 2), show lower bgPC scores than the footprints of modern humans (figure 3b), and therefore point to a bipedal gait that involved a more flexed lower limb posture at foot strike than is typically observed in modern humans. This direct evidence of a bipedal gait that involved relatively more flexed lower limbs concurs with certain inferences derived from Australopithecus skeletal fossils...
In sum, the functional implications of the Laetoli tracks are consistent with previous interpretations of distinctive anatomy in Australopithecus and provide an emerging picture, based on direct records of locomotor behaviour, of a form of bipedalism in early hominins that differed from that of modern humans. We acknowledge that there are limitations to the conclusions that can be drawn from our experimental approach (electronic supplementary material, note S3). But, based on our data, it appears that relative to the specific pattern of gait seen in modern humans today, the Laetoli footprints show evidence of a distinct gait that involved relatively greater limb flexion at touchdown and potentially a less arched foot. These differences were almost certainly not as dramatic as those that distinguish the bipedal gaits of modern humans and modern chimpanzees, but nonetheless they may have had critical wide-ranging effects on the palaeobiology of the Laetoli hominins.
Ultimately, these results support the hypothesis that the evolution of hominin bipedalism was a process [47] during which slightly but significantly different gait kinematics, kinetics and morphology evolved in different hominin taxa. Regardless of the environmental and evolutionary circumstances that may have surrounded the Laetoli trackmakers, direct evidence from the Laetoli footprints suggests that the Pliocene hominins at Laetoli (probably but not certainly A. afarensis) employed a form of bipedalism that was well developed but not equivalent to that seen in modern humans today. While the post-cranial anatomy required for a well-developed bipedal gait may have emerged at an earlier date and persisted for a long time [7], it remains to be seen when, how and why the specific biomechanics of modern human bipedalism evolved."

The consensus then is fairly clear: The Laetoli footprints are markedly NOT human in their physicality. They are similar in gait, but distinct in nearly every other way from the prints made by modern H. sapiens. 

As such, we reach the following conclusion: The Laetoli footprints were definitively made by an Australopithecine and not a member of Genus Homo. This is confirmed by radiometric dating, stratigraphy, anatomy of various members of the Hominin and Hominid clades, and biomechanics of the physical tracks n comparisson to said clade members. 

Below are two sets of prints, the left is A. afarensis and the right is an Aboriginal Human 
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Part 4: So what does Answers in Genesis have to say About all This? 

Not a whole lot, honestly. In "A Look at Lucy's Legacy" the famous "no dinosaurs have feathers" Dr. Menton leads an article concerning some of Lucy's Traits. This is important specifically because by denying A. afarensis's bipedality AiG seems to suggest humans are the only viable candidate for the Laetoli prints (as if all the rest of the australopiths and genus homo aren't in the picture at all.) 

Curiously, the latest news I could find on Aig concerning Laetoli WAS this article on Lucy. The last Laetoli-specific piece seems to have been in 2011 "Laetoli Revisited" or something along those lines.

Here are some quotes from the linked "Lucy" article, as well as some rebuttals. 



  • On the Footprints
“Paleoanthropologist Timothy White, who has worked with both Leakey and Johanson, attests to the obviously human appearance of the Laetoli prints. “Make no mistake about it, they are like modern human footprints,” he explains. “There is a well shaped modern heel with a strong arch and good ball of the foot in front of it. The big toe is straight in line. It doesn't stick out to the side like an ape toe.”11 White, who—unlike Mary Leakey—did associate the Laetoli prints with Lucy, also commented on the human-like gait the prints depict. He said, “I don’t mean to say that there may not have been some slight differences in the foot bones; that’s to be expected. But to all intents and purposes, those Laetoli hominids walked like you and me, and not in a shuffling run, as so many people have claimed for so long.”

Precisely, although it was also these expert anatomists who categorized the DIFFERENCES that the gait and prints had in comparison to true sapiens tracks: the in-line but diagonal big toe, weight distribution unlike both chimps and humans and most importantly the posture the prints implies.

“Yet because radiometric dating of the volcanic tuffs in which the footprints were made points to a 3.66 million year date for them,13 evolutionists maintain these prints cannot be human, no matter what they look like (because humans had not yet evolved).”

That’s not correct though, the reason the Laetoli tracks aren’t human is for the reasons mentioned above. Modern technology allows us to actually empirically compare things like topography as well, and as in the linked study above, this ALSO confirms the identity of the trackmakers as decidedly not human.


  • "More controversy"
 
“The first bit of evidence that convinced Johanson he had found a Hadar hominid back in 1973, the valgus (slightly knock-kneed) angle of the knee, is actually present in some apes, notably the orangutan and the spider monkey. Therefore, the angle of the knee is not diagnostic of bipedality, despite Johanson’s confidence that he had found a new hominid. But the diagnosis of bipedality rests on more evidence, including the australopithecine pelvis and the suggestion of a lumbar curve in some reconstructions.”

The knee seen in orangutans is no where near the degree that we see in the hominids. It is a TYPE, but it is not actually conducive to bipedality especially in conjunction with the animal’s other traits. The knees of arboreal "clamberers" is more bow-legged than that seen in the australopithecines in order to amble using four limbs. It gives them a flexability not seen in the more terrestrial Great Apes! 

As for spider monkeys, the same is true. It is a localized adaption that looks nothing like the degree of femoral angling we see in the hominins. 


“in the Journal of Human Evolution, offer a different reconstruction allowing for a unique sort of locomotion. Berge writes, “The results clearly indicate that australopithecine bipedalism differs from that of humans. (1) The extended lower limb of australopithecines would have lacked stabilization during walking; and (2) the lower limb would have shown greater freedom for motion, which can be interpreted as the retention of a partly arboreal behavior.”

This is accurate and is precisely what we (and Darwin) expected to find. Going overnight to efficient bipedality would falsify evolutionary theory entirely.



  • "Handy anatomy"
“Lucy’s bones show the features used to lock the wrist for secure knuckle-walking seen in modern knuckle-walkers.”


Yes, again, this is expected. There would be no immediate pressure to actually lose this trait, especially considering although AiG proposes the primary reason hominids evolved bipedality was to free the hands, this is not so. This was a convenient side effect. The true reason is unknown, although many ideas exist. Much is there to support the climatographical approach that the climate’s change to savanna would have favored being able to view over the grasses for predators, and pressured (to some degree) the exodus from the trees. 
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Part 5: Conclusion TL;DR

Despite numerous attempts by Answers in Genesis to debunk the Laetoli footprints as nothing more than human tracks (and by proxy, attempts to debunk australopithecine bipedality) they fail on nearly every level and are forced to show what little knowledge about evolution they actually have. 

The nature of the Laetoli Footprints being decidedly non-human and VERY indicative of the local australopithecine population of the time is well understood by anthropologists and anatomists alike. Experiments have been repeatedly performed to compare biomechanics and have independently reached this conclusion. 

As such, the fact that Answers in Genesis has not released a commentary on the latest 2016 findings is telling and does not bode well for their case that the prints are those of an anatomically modern human. 

I suspect the next angle will be something along the lines of "So what if it's a bipedal ape. That doesn't mean we evolved from it!" 

And the question then becomes: where does one draw the line then? At the apes that walk? The apes that think? The apes that use tools? 

All of these categories describe not only us, but the australopithecines too. Because there is no physical means by which to separate humans from apes, any more than one could separate dogs from canids.
 
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Arthropods and Their Evolution (Additionally, How They Preclude A Global Flood and Young Earth Creationism)

7/18/2019

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Arthropods are an incredibly diverse group of animals, with over one million species known on our planet. How did these organisms evolve? Why are they so prolific? And how does their existence impact a "literal reading" of Genesis? Let's dive in to the wonderfully populous world of arthropods. 

Part 1, What Makes an Arthropod?


What do we mean when we say "bug"? How about "insect"? Typically when people think of arthropods, they are thinking of what we colloquially term as insects and bugs. They think of beetles and bees, or of ants and wasps. Perhaps the odd mantis blinks into someone's mind. 

But arthropods actually encompass far more than that. 

So who is apart of the not-very-exclusive arthropod club? Well, there are quite a few, and they break down in a rather interesting way! 

Below, I will paste a slide from my old entomology professor's lecture on arthropod and panarthropod classification (credit to Ray Fisher) And then we can go through what makes each group unique from one another. 

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Of course, each group can be further broken down (arachnids contains spiders, scorpions, mites and ticks for instance) but for our purposes this is as deep as we will go. 
So first off, what makes a Panarthropod? 
These guys possess the following: 
- alpha chitin throughout the cuticle of the animal
- Metamerism (body is organized into segments that are similar in structure) 
- Tagmosis (metamere segments are organized into functional units known as tagmata)
- Gangliated nerve cord is present
- The ends of each appendage have claws

So why are we talking about panarthropods in a post about arthropods? This is because the ancestor of all arthropods was a Panarthropod. These organisms lack intense formal classification, but we will address them shortly. ​


(pictured below, the panarthropods)
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We next zoom in on the arthropods. These animals can be classified in two distinct clades: 

The cheliceratans (sea spiders, horseshoe crabs and arachnids) which are characterized by:
-chelicerae (the frontal digits we refer to as their "fangs")
-pedipalps (the "mini legs" near the chelicera)
-8-14 legs
-Only two tagmata (pro/opisthsoma)

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The mandibulatans (myriapodans and pancrustaceans: hexapods and "true" crustceans) which are characterized by:
-Mandibles (think the chelicerae with a movable opposing "fang")
-Two pairs of maxillae
-1-2 pairs of antennae
Since we are primarily honing in on hexapods in this post, we will add that hexapods are unique from the other mandibulatans thanks to their 3 tagmata (head, thorax, abdomen) single pair of antennae and 3 pairs of walking legs. 

Hexapods can thus be further split into the 30 orders that compose the more common animals we see today:

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Part 2: Panarthropods of the Past (The Evolution of Arthropods)

Arthropod evolution is heavily shrouded in mystery, in part due to the fact that they evolved so early in history. It is universally accepted that they appear in droves in the Cambrian, but many entomologists are no proposing that their first emergence was in the Ediacaran period some 555 MYA with parvancorina and spriggina (pictured below)
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Certainly though, by the Early Cambrian the first organisms that looked vaguely arthropod-like were emerging on the scene (Braun, A.; J. Chen; D. Waloszek; A. Maas (2007))
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(It should be noted that pikiia is considered an early chordate while the others are considered lobopods/early arthropods)

The Cambrian's conditions influenced the enormous radiation of forms that the panarthropods would experience. Warm seas with an abundance if niches for the non-sessile animal allowed strange animals to thrive, including the five-eyed opabinia or the enormous anomalocaris (pictured below)

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Arthropods dominated the seas for quite some time, and when the chordates finally began to catch up to the arthropods (now diversified from the panarthropods as known from the fossil record) it was the Late Silurian and they were beginning their march onto land. This was due in part to the presence of plants who had begun their own colonization millions of years earlier in the Ordivician. The land was a habitat free of immediate predators for the first arthropods, and the plant denizens provided shelter and sustenance. They were already prepared, you see, as these animals had exoskeletons whose chitinous composition protected from desiccation and whose jointed legs could spar against gravity. Unlike the early tetrapods, water dependence was not on the forefront. 

Chordates, slow as ever, would not catch up until the Devonian and even then they would be somewhat sluggish until the Carboniferous. This left the land to the creepy crawlers, and they began to radiate out from their most basal forms. We will be examining some of the transitional Chelicerates and Mandibulates.

Chelicerates of the Silurian were some of the first to radiate as the trigonotarbid Palaeotarbus jerami, from about 420 million years ago shows us. 
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This animal looks very much like a mite or a tick, which suggests that the first chelicerates likely adapted the trademark double-tagma prior to many of the specializations spiders and scorpions possess. 

Next in the Devonian we see more chelicerates emerge. Attercopus fimbriunguis is a spider-like animal closer to our modern iteration. It had the organs necessary to produce silk, but lacked the spinnerets themselves, meaning web-building (if it occured) was likely far more clumsy. 
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Blattodeans, the order that concerns roaches and termites, sees it's beginnings in the form of Archimylacris who, like Attercopus, is also a Devonian-dweller. It differs from modern roaches in that it's ovipositor is much larger, perhaps a holdover from earlier hexapod ancestors, and it has sticky pads on it's legs which may have allowed it to cling upside-down or walk along smooth surfaces. This is not present among modern roaches.
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Pollen makes it's appearance in the Triassic, although the granules are heavy and more basal in comparison, their bulky form unable to easily attach itself to insects which may assist it's pollination journey.  

It should should come as no surprise then, that once pollen takes it's more lightweight form, organisms begin to specialize in nectar collection and thus pollen dispersal. 

And it is there of course, at the emergence of the pollinators, that we should begin to find some of our lepidopterans (moths and butterflies) and hymenopterans (ants, bees, wasps).

The oldest known Lepidopteran fossil is a basal moth lived during Lower Jurassic period some 190 million years ago. It had a single pair of scaled wings with a pattern of veins similar to Caddisflies. Eolepidopterix jurassica, another Jurassic lepidopteran,  was another two-winged fossil that had setae (scales) on both of its wings. Modern lepidopterans have four wings, and setae. 
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The first bee fossil is found in the upper Cretaceous, and is something of a hybrid between a "flesh-eating" wasp (a specialized form) and that of a modern bee. Boasting a mixture of predatory and pollen -collecting features, it is suggested that this animal (along with the other pollinators) was partially responsible for the angiosperm boon that took place at that time. 
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Finally we meet sphecomyrma, the wasp/ant mosaic. You wouldn't think it, but these animals have quite a bit in common. Both are highly euscial and work under similar colony structures. The current entomologic hypothesis is that ants evolved from wasps, as the latter appears prior to the former in the fossil record. Another hint to this is the nature of their eusociality. Eusocial animals are sometimes called "Superorganisms" as the colony behaves somewhat like a massive organism wherein the inhabitants are merely parts of a whole. 

Euscoiality is a trait seen late in evolutionary history and primarily in hymenopterans and in some blattodeans (namely termites). This is partially known from the lack of colonies and hives in the fossil record. For us to gauge which animal, ants or wasps, is more basal Eusociality may be a good place to look. 

In the modern world, there are solitary wasps. These are wasps whose species do not form colonies and instead lay eggs and guard them after mating. There are no solitary ants. 

There are also wasps which experience tense eusociality, these are species which maintain order through infighting among the females. this eusociality can result in the death of the queen or the workers and is considered a "lower" form of eusociality. There are no ants with tense eusociality. 

Finally, there are both orderly eusocial wasps and ants. This serves to complement the fossil record's claim that ants are a derivative of a wasp-like common ancestor. 

Part 3: Arthropods vs Young Earth Creationism

So now we know all about arthropods and are acquainted with many of their transitional forms. What does all this have to do with Young Earth Creationism (YEC)?

Well, YEC tends to take what they think is a "Literal" reading of the book of Genesis and use it as history. Furthermore, many (not all) YEC's believe that the inerrant nature of the Bible means it is without any error at all, in any sense. This leads to quite drastic efforts to force the text to say things it does not, such taking the verse of Isaiah 40: 22 which says "It is He (God) that sits above the circle of the Earth" and trying to force the word circle to mean sphere, thus "fixing" the fact that the writers of the bible clearly believed in a flat Earth sitting on pillars and surrounded by the firmament. There is indeed a Hebrew word for sphere, and the author opts not to use it. YEC's thus force an Ancient Near East culture to say things no other ANE culture would have said, and propose it was God's revelation (ie, God TOLD them the Earth was round). 

Of course, there is not a single time in the bible that God relates a truth to the ancient Hebrews about the natural order of science. Those who hold a faith may propose that this means God is speaking to them on their level, choosing to meet them where they are at, and that inerrancy then is about the message.  Others take the stance that this is simply proof that the Hebrews were just another ANE culture with their own god. 

Either way, they clearly were not privy to the true science: the earth is round. 

And so, the same happens when we examine Arthropods in the Old Testament book of Genesis. Let's take a look at why a "literal" reading is problematic. 

YEC Claim 1: There was no Death before the Fall of Man in Genesis 3. (AiG)

Answers in Genesis proposes that the Bible says there was no Death at all prior to the Fall of Man. First and foremost this is not a biblically sound argument to make but let's say for arguments sake that is what the author meant.

Ken might route around plant death by insisting that they lacked the breath of god (nephesh chayyah)  that humans and other animals had, but he neglects to consider the arthopods. Won't someone please consider the arthropods! 
Mites, the smallest chelicerates, breathe. As do ants, and as do all arthropods. They take in oxygen, the breath of God so proposes Ken, and they expel CO2. 
I suppose in the Garden of Eden everyone was really quite careful where they stepped. 
And I suppose all the insectivore animals chowed down on fruits. Even this guy, the humble anteater. 

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YEC Claim 2: Insects WERE or WERE NOT taken on Noah's Ark (AiG)

This article by Answers in Genesis is notably wishy-washy on whether or not arthropods (although AiG only refers to insects, so I guess all the arachnids and crustaceans are toast) made it onto the Ark built by Noah and his family. 

From a standpoint of evidence based science Noah's ark either never occurred or was perhaps a local flooding event that may have been exaggerated. But the folks at AiG take this tale as 100% history. Let's examine why a literal reading of this story is fraught with Arthropod Issues. 

Genesis 6

 "I am going to bring floodwaters on the earth to destroy all life under the heavens, every creature that has the breath of life in it. Everything on earth will perish. 18 But I will establish my covenant with you, and you will enter the ark—you and your sons and your wife and your sons’ wives with you. 19 You are to bring into the ark two of all living creatures, male and female, to keep them alive with you. 20 Two of every kind of bird, of every kind of animal and of every kind of creature that moves along the ground will come to you to be kept alive. 21 You are to take every kind of food that is to be eaten and store it away as food for you and for them.”

Genesis 7

" They rose greatly on the earth, and all the high mountains under the entire heavens were covered.
 20 The waters rose and covered the mountains to a depth of more than fifteen cubits.[g][h] 21 Every living thing that moved on land perished—birds, livestock, wild animals, all the creatures that swarm over the earth, and all mankind. 22 Everything on dry land that had the breath of life in its nostrils died. 23 Every living thing on the face of the earth was wiped out; people and animals and the creatures that move along the ground and the birds were wiped from the earth. Only Noah was left, and those with him in the ark."

According to a literal reading of the second chunk here, it seems to me that a literal reading NECESSITATES bringing the arthropods on the ark as EVERY living thing outside the ark perished. So taken literally this is not an optional interpretation. 

So IF Noah took arthropods, which did he take? Even if we are using the YEC concept of "kind" ratehr than species, how would Noah have cared for the Hymenopterans, whose females require many males and whose males are haploid organisms? 

What about the Odonatans (damselflies and Dragonflies) whose lifespans are short and whose mating strategies aren't always successful? Did Noah breed them?

What about the Arachnid ticks, who require bloodmeals? Or the Parasitic wasps? 

How would he care for the nectar sipping lepidopterans? Or the mate-gobbling mantises? What of the eusocial ants who require a colony?

And who will stop the mighty termites from sinking the vessel! 

It's problematic. 

YEC Problem 3: Leviticus 11: 20-23

"All flying insects that walk on all fours are to be detestable to you. There are, however, some winged creatures that walk on all fours that you may eat: those that have jointed legs for hopping on the ground. Of these you may eat any kind of locust, katydid, cricket or grasshopper. But all other winged creatures that have four legs you are to detest."

This should be self explanitory. Arthropods have at least 6 legs.

Conclusion/TL;DR

Arthropods are numerous in species today and have dominated this planet longer than we have been around. They come in many shapes and sizes and many of their transitionals track their progression to modern forms. They also create glaring problems for a literal reading of the Bible, as well as the proposed ideal of inerrency in the form of: no mistakes, ever, period. 

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The Iridium Anomaly and Earth's Impact Events Both Preclude a Young Earth and a Global Flood

7/14/2019

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Iridium is an incredibly unique element. It rests on the periodic table with atomic number 77, and is the second densest metal present. It's also the most corrosion resistant metal, maintaining it's integrity at temperatures up to 2000 degrees Celsius. 

It also obliterates Young Earth Creationism. 

Part 1: The Iridium Shortage

Our planet is abundant in many elements, particularly those conducive to life. But as everyone knows, there are elements that are rarer than others. Iridium fits into this category. 

This element one of the rarest of those found in Earth's crust. This means that it is essentially present enough to be considered among the crustal makeup, but practically it is very difficult to find. How rare are we talking here? 

Well only 3 tons of iridium are produced and consumed in the Earth's Crust annually. 

Gold is thus 40 times more abundant in comparison. 

What this means is that finding large quantities of this element is very rare, and when it occurs it is usually a big geologic deal. This is because large iridium deposits on our planet usually have an story to tell, as the element's presence is very much out of this world. 
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Part 2: The Iridium Surplus

While our planet's crust may be lacking in this metal, it seems to call another type of place home:

Iridium is abundant in meteorites. (Becker, Luann (2002))

Found at .5 ppm (parts per million) or more, this element sets up shop in the majority of recovered meteorites discovered post-impact on our world. Compare this to the .001 ppm that our crust sports and it becomes clear that wherever mass amounts of iridium are found, geologists and astronomers begin to look for the smoking meteorite. 

And curiously, many of these heavily iridium-infused locations are craters, indicating an impact event occurred at some point and left iridium behind in the soil and rock. And it is this fact that leads us to an important point that many already accept, but creates big problems for YEC for reasons to be addressed: 
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Part 3: Iridium and the Dinosaurs

In 1980, Luis and Walter Alvarez, both prominent geologists, noticed something strange. 
It was well known at the time that the dinosaurs had gone extinct due to some enormous global event and that this event was recorded in the rocks. No dinosaur fossils could be found after a geologic formation known as the Cretaceous-Paleogene (K-Pg) boundary after all, meaning whatever had caused this boundary (in most places denoted by a large rock band of unique composition) likely also triggered the mass extinction event. 
Meteor impacts were being thrown around, but like the supervolcano hypothesis there was nothing supremely solid to back it up. 
But that's when the Father-Son team noticed that this band of rock, which could be found globally and marked the disappearance of the dinosaurs everywhere,had incredibly high concentrations of iridium. Iridium, the element that was primarily found in meteorites. 
But to deposit such a massive amount of the rare metal, and to do so all over the world, the impact event would have to be enormous. 
Enter Chixulub Crater. 
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This enormous crater was formed by a large asteroid or comet about 11 to 81 kilometres (6.8 to 50.3 miles) in diameter, is found in the Yucatan Peninsula in Mexico. This crater is almost certainly the result of the stellar object that collided with Earth and killed the dinosaurs off in a resulting climactic disruption. 
How do we know this? 
  • Chixulub Crater is chock full of iridium and is dated precisely to the time period the global iridium band was laid down. (Hildebrand, Penfield, et al.)
  • Chixulub Crater is also chock full of tektites, small balls of hardened glass that occur as a result of superheated impact events and are also commonly found in the K-Pg boundary globally.
  • It has jumbled, coarse rock fragments that are typical of either a mega-tsunami or an impact event
  • It possesses an andesite layer, typical of major impact events.
So. We know that 65-ish MYA an enormous asteroid or comet hurtled through our atmosphere, slammed into our planet's crust and left Chixulub Crater as well as a global band of debris made up of iridium and tektites. We also know that after this impact event, there are no more dinosaurs in the fossil record. 

So what exactly does this have to do with Creationism?

Part 4: Iridium and Creationism

According to Young Earth Creationists, the Earth was created ex nihilo some 6000-10000 years ago, piece by piece over the course of 7 days. This is due to a "literal" reading of the Bible, which continues onward to suggets that 4000-6000 years ago (depending on the group) God sent a Global Flood to wipe out all life on Earth except for Noah and his family, who loaded 2 of each kind of animal onto an enormous wooden vessel and sailed to safety.

With this knowledge we can make some inferences. If this is what is to be believes than:
  • Prior to the Global Flood, there were no enormous impact events such as that of Chixulub as all life would have been wiped out. 
  • Because of this, ALL impact events that would cause mass extinctions MUST have occurred DURING the global flood. 
  • No impact events occurred after either, for the reasons mentioned in inference 1. 
  • This means the Global Iridium Anomaly was NECESSARILY laid down during the Global Flood
  • It also means ALL iridium deposits were laid down during the flood, as they are only found by mining the Crust, unusual Volcanic Events and MOST commonly by impact events. 
Here lies the issue. 
Iridium is the second densest metal on the periodic table. Dense things sink. Underneath the Global Iridium Anomaly in locations such as the Grand Canyon we have enormous bands of Limestone, a mineral that is very fine and takes a LONG time to settle. 


Most limestone is made of the skeletons and shells of trillions upon trillions of marine microorganisms. Deposits can be hundreds or even thousands of meters thick. Approximately 1.5 x 10^15 grams of calcium carbonate get deposited on the ocean floor annually [Poldervaart, 1955]. This is INCREDIBLY slow. Furthermore, this mineral cannot even begin to settle out of water unless the water is calm and warm. 

With all of this in mind, there should NEVER be ANY limestone below an Iridium layer if they were deposited in a single flood over the course of a single year. 


This is true no matter when the impact of Chixulub is placed during the year-long flood. 

If it is at the beginning, the lowest flood layer, that which is above the basement granite, should be iridium. It isn't. 

If the impact is sometime during the middle of the flood year, we should see a steady gradient of mineral/layer density decreasing from the anomaly, but we don't. We find silt, limestone, evaporites and clay above AND below the iridium layer. 

But iridium is not the only problem. 

Part 5: Impact Events and YEC


Pasted below are the top 10 biggest known impact events from Earth's History. These were taken from a National Geographic article.  ALL of these impacts must have occurred during a single year according to Young Earth Creationists. 


1. Vredefort Crater
Asteroid impact date: Estimated 2 billion years ago
Location: Free State, South Africa
Specs: Also known as the Vredefort Dome, the Vredefort crater has an estimated radius of 118 miles (190 kilometers), making it the world's largest known impact structure. This crater was declared a UNESCO World Heritage Site in 2005.

2. Sudbury Basin
Asteroid impact date: Estimated 1.8 billion years ago
Location: Ontario, Canada
Specs: The Sudbury Basin is considered one of largest impact structures on Earth, with an estimated diameter of 81 miles (130 kilometers). Dating back 1.8 billion years, it is also one of the oldest known impact structures in the world.
3. Acraman Crater
Asteroid impact date: Estimated 580 million years ago
Location: South Australia, Australia
Specs: Located in what is now Lake Acraman, this impact structure has an estimated diameter of 56 miles (90 kilometers).
4. Woodleigh Crater
Asteroid impact date: Estimated 364 million years ago
Location: Western Australia, Australia
Specs: This crater is not exposed at the surface and has led to many discrepancies regarding its actual size. Reports on its diameter vary from 25 to 75 miles (40 to 120 kilometers).
5. Manicouagan Crater
Asteroid impact date: Estimated 215 million years ago
Location: Quebec, Canada
Specs: This impact crater formed what is now Lake Manicouagan. Even with erosion, it's considered one of the largest and best-preserved craters on Earth, with an estimated diameter of 62 miles (100 kilometers).
6. Morokweng Crater
Asteroid impact date: Estimated 145 million years ago
Location: North West, South Africa
Specs: Located near the Kalahari Desert in South Africa, this crater contained the fossilized remains of the meteorite that created it.
7. Kara Crater
Asteroid impact date: Estimated 70.3 million years ago
Location: Nenetsia, Russia
Specs: Now greatly eroded, the Kara crater is a non-exposed impact structure in Russia. Some have claimed that the impact structure actually consists of two adjacent craters: the Kara and the Ust-Kara crater.
8. Chicxulub Crater
Asteroid impact date: Estimated 65 million years ago
Location: Yucatán, Mexico
Specs: Located on the Yucatán Peninsula in Mexico, many scientists believe that the meteorite that left this crater caused or contributed to the extinction of the dinosaurs. Estimates of its actual diameter range from 106 to a whooping 186 miles (170 to 300 kilometers), which if proved right could mean it's the biggest.
9. Popigai Crater
Asteroid impact date: Estimated 35.7 million years ago
Location: Siberia, Russia
Specs: Russian scientists claim that this crater site contains trillions of carats of diamonds, making it one of the largest diamond deposits in the world. These diamonds have been referred to as "impact diamonds."
10. Chesapeake Bay Crater
Asteroid impact date: Estimated 35 million years ago
Location: Virginia, United States
Specs: Discovered in the early 1980s, the Chesapeake Bay Crater is located approximately 125 miles (201 kilometers) from Washington, D.C. Some estimates suggest this crater is 53 miles (85 kilometers) wide.

As it turns out, impact events release heat. And heat in mass quantities can ONLY be dissipated through our atmosphere.

Whitcomb and DeYoung, both Flood Geologists, propose that given ALL cratering on earth occured during this year, the event was probably similar to the cratering events seen on the Moon. Just the LARGEST of the lunar craters released 3 X 10^26 joules of heat. 

For reference this is just shy of the joules (5.6 X 10^26) required to boil all the Earth's oceans.

Part 6: TL;DR Conclusion

Both Impact Events AND Iridium deposits tell a story of a planet bombarded through the Eons, not one nearly shattered in a single year by all it's collisions. In order to combat this YECs would need to provide an alternative method for dissipating heat from impact events, as well as a reasonable explanation for the layering of the Iridium Anomaly. 
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Egyptian Chronology and How it Precludes a Global Flood (And Also a 6000 year old Earth)

7/13/2019

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A complaint I have seen proposed before is that we can't know anything about the past before humans because there were no humans to witness the event. "You can't know, you weren't there!" This is an actual defense put forth by actual adults at the head of certain Young Earth Creationism websites.
My minor in undergrad was Anthropology, primarily Bioanth (human evolution) but we had to take a fair bit of cultural anth. as well, and I chose to spend my time in an Egyptology Lecture. So much of my knowledge is based off of the textbook "An Introduction to the Archaeology of Ancient Egypt" by Bard, and "A History of Ancient Egypt" by Mieroop (from 2015 and 2010 respectively).
So in this post we're going to examine how Egyptian Chronology is problematic for a literal Genesis interpretation, and also WHY we know the Chronology is sound. I am by no means an Egyptologist, but I am using sources written recently by very good ones, so if you have more in depth questions I would recommend checking them out.
Part 1: Egyptology 101
Ancient Egypt is located where modern Egypt is today, in *Northeast Africa hugging the Nile river. It can be separated into several time periods: Naqada 1-3 (Also known as the Predynastic Period), Old Kingdom, First Intermediate, Middle Kingdom, Second Intermediate, and the New Kingdom.
We primarily care about the Predynastic Period and the Old Kingdom in this post, the reasons being the former begins the concept of Regnal years (how long a Pharaoh ruled) and the latter sees the building of the Pyramids of Giza.
Part 2: The Naqada Problem
Radiocarbon dating is a double edged sword for many YEC's. On one hand, it can corroborate certain biblical events as well as the consistency of parts of the modern text. On the other hand, Naqada 1 begins in 4400 BC according to the multiple radiocarbon dates of fossil remains of humans and other animals, grains and reeds. This is outright problematic because using Lightfoot's age of 6000 years old, this enormous culture would be creating pottery, jewelry, their own religions, and trading with the equally large Nubia in a vacuum.
It becomes more problematic when Naqada 3 rolls around with the advent of writing systems and Regnal Years with which to record history. These writing systems are the first hieroglyphs, and in conjunction with graphic narratives on palettes, they begin to record the first Kings. This will become more relevant in a moment.
Part 3: The Flood and the Pyramid Problem
The Pyramids of Giza were not the first pyramids of Egypt. Human ingenuity is an incredible thing, but usually requires some trial and error. The first even remotely successful pyramid was built by the stubborn Pharaoh Sneferu (2613-2589 BC). He messed up several (leaving behind the odd-ball Bent Pyramid) before a success with the Red Pyramid (the first true Egyptian Pyramid) before his death.
Sneferu was succeeded by three kings in a series, obsessed with pyramids. Khufu, Khafre and Menkaure. Each built one of the Great Pyramids of Giza and filled them with goods for their afterlives.
This means the three pyramids of Giza were all finished, along with the two other standing pyramids of Sneferu, the Sphinx and hundreds of Mastabas (large funerary monuments of past Kings) by the year 2490 BC at the latest.
These pyramids and monuments were covered with enormous, vain inscriptions of the Pharaohs who built them, including stone Steeles, cattle and grain counts and trade information.
Answers in Genesis, a YEC websites, places Noah's flood in the year 2348 BC. This is 142 years AFTER the pyramids were built.
This means the Egyptian monuments, which are today falling apart from time alone, survived a global deluge which was supposed to shift tectonic plates and form the entire current geologic record. These limestone monuments somehow avoided being buried under thousands of feet of sediment, and survive to today with zero water damage evident.
Then, after said flood, Noah's kin repopulated, removed to Egypt and picked up precisely where the Egyptians had left off before perishing in the Global Flood.
They deciphered and learned the hieroglyphics, accepted the Egyptian Pantheon, picked up the Regnal Kings list where Menkaure left off, and never ever mentioned a global deluge.
Of course, this is ridiculous. This is beyond impossible. So, AiG and others have decided not that Noah's Flood may have been localized or perhaps allegorical, but that Egyptian Chronology is wrong.
Does this claim have any validity? Could Egyptian history be off enough to accommodate the YEC dates?
Part 4: No, it couldn't. Egyptian Chronology is Solid.
So let's entertain for a moment the possibility that Egyptian History begins after Noah's Flood. That Naqada 1 starts then. How is our population looking for those stats?
Not Great, is the answer.
Assume human population doubling time as AiG does for many divergences from the flood which is a double of population every 20 years. Mind you, this is with NO MORTALITY and NO FAMINE, PLAGUE, WAR.
160 years after the Flood date AiG gives, Egypt was “founded” (2188 BC)… with a total of 2048 people in the WORLD.
In 2234 BC, AiG says Babylon was founded. This is 114 years after the Flood. The total WORLD population would be 512.
Under the occasionally used doubling rate, it is simply not possible given these WORLD populations are shared with: Sumerian, Assyrian, Akkadian, and Babylonian civilizations and any and all small traveling bands, tribes and budding societies. Additionally, numerous civilizations are dated to this time period around the GLOBE.
Not to mention if this is the population rate used, who is building these massive structures? There aren't enough hands.
But back to the point: Egyptian Chronology is solid. Why?
There are many reasons.
First is the Regnal years. We can count back using King's Lists and figure out just how long each Pharaoh ruled for. Using this method, we arrive at ruling dates for the Sneferu and company which are THEN confirmed with radio carbon dating the organic material in the pyramids (namely, reed mats and wood).
Secondly, we can cross reference this with cattle censuses and festivals (such as the Sed festival or Apis Bull celebrations). These festivals are recorded in ceremonial papyrus writings, and the censuses are recorded as well, as a matter of bureaucracy.
Third, we can corroborate with OTHER nation chronologies. If Babylon's king mentions Egypt's Pharaoh, and the regnal year counts for both indicate the same time period, we can be assured of the method and the Chronology. Egypt HAS this, in the form of the Amarna Letters, diplomatic communications between the royalty of the Kingdoms of Mesopotamia (Babylon, Hatti, Egypt, Mitanni and Assyria)
Fourth, is dendochronology corroboration. Using wood from Egyptian monuments and ships (Uluburan shipwreck, Sneferu's Cedar Ship) we can count rings back and obtain dates as well.
Fifth is Radiocarbon Dating. This one is interesting, because Answers in Genesis is known for rejecting it as a dating method outside of the very recent. Interestingly enough, they have kindly given us a maximum for radiocarbon dating's efficiency and it's 5730 years. The vast majority of Egypt's history falls inside these constraints and supports conventional Egyptian Chronology.
Part 6: TL;DR
The history of ancient Egypt is but a single example of archaeologic findings which present what I find to be insurmountable problems for Young Earth Creationism. Furthermore, to accept a global flood one must cling to a universally panned alternative chronology (with it's own insurmountable problems) or the idea that the pyramids could survive a flood without damage, and the people who resettled the location simply picked up where the former left off.
This is a case in which we have what YEC's so frequently complain we don't have: eyewitnesses.
And they speak for themselves.
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Transitional Species Handbook: Tetrapods (Mammals, Reptiles, Amphibians) are Definitively the Descendants of a Lineage of Pelagic Sarcopterygians (lobe-finned fish)

7/13/2019

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Let's talk fish this evening fellow tetrapods!
Credit again to Donald Prothero for the diagrams pulled from his book: "Evolution: What the Fossils Say and why it Matters" Second Edition. 
Tetrapoda is a superclass including all mammals, reptiles (birds as well) and amphibians. This group is considered by mainstream science to have emerged sometime in the Devonian period around 350 to 380 MYA from a line of sarcopterygians, or lobe finned fish. This group includes modern coelacanth and itself is likely an evolutionary lineage descending from the proto-lungfish known as Dipterus.
How do we know this? Are there any criticisms?
The following post will examine the various fossil transitions we have from Eusthenopteron to the Tetrapodomorphs (and Temnospondyls), and examine the YEC criticisms of this lineage.
Part 1: A Fish Called Eusthenopteron
As always, the first task with examining transitional species is to identify the primary differing traits between the organisms with traits considered more "primitive" and that with traits considered more "derived". These terms aren't ideal, and it should be noted that in this post we are primarily using them to denote change in traits through geologic time.
Eusthenopteron Traits
  • “Fish” style skull (tall and narrow, sockets to the sides)
  • No neck or cervical-style vertebrae
  • No distinct hind-limbs
  • “Webbed” tailfin
  • No distinct digits
  • No true wrist
  • External Gills (with gill chamber)


Tetrapodomorph Traits
  • “Tetrapod” style skull (flat and wide, sockets angled forward)
  • Neck and cervical vertebrae
  • Distinct hind-limbs
  • Reduced tail that usually drags
  • Distinct digits
  • True Wrist
  • No External gills


Part 2: The Land Before Spine
The Devonian period was an odd time. It is generally known as the "Age of Fishes", but it should be noted that at this same time vast fern-like forests were beginning to stretch across the land, continuing their invasion from the Ordovician millions of years earlier. This is important, as the more the plants dominate, the more available habitat for the arthropods: a future food source for the tetrapods!
But for the most part this is a warm and humid time; ideal for more invaders from the sea. With the coast as free real estate, the sarcopterygians of the pelagic zone have an opportunity to seize.
Euthentopteron (385 MYA)
Euthenopteron is definitely a fish, but it bears unique characteristics that will come in handy in it's descendants future on land. It is the only organism in the sea during this time to have labrynthodont teeth, a trait found in the first tetrapods, as well as the skull roofing pattern and appendicular bones which appear in the vertebrate land lubbers. Its fin endoskeleton, which appears to be a more advanced version of the Devonian coelacanth’s, bears a distinct humerus, ulna, and radius (in the fore-fin) and femur, tibia, and fibula (in the pelvic fin). However, this animal is still clearly a fish. It bears gills and a webbed tail fin, lacks a neck, a true wrist and tetrapod vertebrae.
Panderichthys (380 MYA)
While again, clearly still a fish (gills, fins, webbed tailfin, no neck or true wrist) we see the beginnings of the wrist and forearm developing skeletally. Compared to Eusthenopteron, the skull shares more in common with tetrapods than fish, both in roofing and in shape (flatter than it is tall). The pelvic girdle continues to develop as well, and the dorsal and anal fins have vanished. The vertebral column is ossified and beginning to look more like the spine of a tetrapod. Nares are moving to a tetrapodomorph position as well. This animal likely did not leave water, but the pectorals are developed enough that it is possible it was capable of squirming from closely located bodies of water.
Tiktaalik (375 MYA)
Neil Shubins famous transitional! Tiktaalik is a lovely mosaic of traits: Head is flat and wide like the tetrapods, a wrist that is continuing to advance (bones differentiating), the interior bones of arm/wrist are stronger and padded for “pushing up” and the eyes are on the TOP of the skull. Tiktaalik bears bones for heavy pectoral muscle attachments allowing it to push up and out of the water. A NECK has appeared, along with muscle attachments for moving head side to side, and accompanied by cervical vertebrae. However, it has fins, no digits and scales (the tetrapods have primarily skin). And perhaps the most telling transitional trait: Tiktaalik has both gills AND lungs. This animal likely could easily migrate from pools of water, although it's life is still primarily spent there.
Ancanthostega (365 MYA)
This animal was certainly spending some time outside of the water, although it would have been somewhat cumbersome. Digits are fully developed, but wrists still are not, thus, due to the wrist immobility, it likely still spent most time in the water and clung to plants with it’s “hands” Teeth remain labrynthodont and the skull is entirely tetrapod-like. Interestingly enough, there are eight digits on each limb not the five we've expect from tetrapods. But even with these odd hands, four limbs, each with digits, are present meaning this animal could likely move between pools of water. Gills are present still, along with lungs (as with lungfish).
Ichthyostega (365-360 MYA)
Ichthyostega differs from Acanthostega in two primary ways: it's ribs and it's wrists. Ichthyostega's ribs are far more robust, and they overlap, meaning this animal would not have struggled under it's own weight while walking. It also has full mobile wrists, meaning it could traverse land far easier simply due to it's enhanced mobility. Interestingly enough, Ichthyostega has only seven digits per hand/foot, a step towards our standard of five. The various fossils we have indicate it was more adept at terrestriality as a juvenile, returning to a primarily aquatic life as an adult, which would suit it just fine as it's gills are still present.
Tulerpeton (365-360 MYA)
The seven toes diminish to six in this animal. It possesses all the land attributes which gave Ichthyostega an edge, and has lost it's gills. However, a new adaption give Tulerpeton an additional trick: it's neck and pectoral girdle aren't connected. This means it can lift it's head up and down rather than just side to side, allowing it to peek above the waters while obscuring the rest of it's body. A considerable hunting advantage. The plants it's fossils were found with indicate a brackish habitat where salinity and water level varied wildly. This paints a picture of a stealthy pool-hopper patrolling the deltas.
From here, the various forms take off even more, specializing in odd ways for over 30 million years. And down the line we have a clear example of a "typical" tetrapod in:
Proterogyrinus (330 MYA)
This enormous tetrapod (6-7 feet long) is likely not the first of the typical tetrapods, but it is a very well preserved example. A monstrous early tetrapod, Proterogyrinus is fully terrestrial, five-toed and squat with a flat, salamander-style head. It has a non-webbed tail dragging behind, true wrists and five digits, while being robust and able to move quickly on land
So with the players in the lineage outlined, lets examine some of the additional facets of tetrapod evolution before diving into the criticisms.
Part 3: The Terrestrial Mystery Tour
So why leave water in the first place? At a light glace, it seems like these animals had it made in the sea. But the water sported many dangers which likely pushed the sarcopterygians into the pegalic zones, coasts and deltas. Heavy set predators such as dunkleosteus lurked in the deep water, along with the continued reign of the sharks. Once in the shallows, it is likely these animals wandered into hybrid territories such as mangrove swamps or shallow deltas.
Now, already adapted to breathe air and move around in shallow waters near land as a protection (similar to modern fish and amphibians, which often spend the first part of their life in the comparative safety of shallow waters like mangrove forests before migrating outward) these animals occupied two very different niches partially overlapped with one other.
The land along the water thus became the less crowded, less dangerous option for those juveniles living nearby, and those species who could take advantage of it were rewarded with a directional selection for terrestriality.
Those who ventured onto land also gained a new food source to take advantage of: the arthropods living there.
Of course there are some enormous challenges to switching from the sea to the land (or vice versa). We covered already the skeletal changes which needed to occur, as well as the steps to breathing air exclusively (gills, gills AND lungs, lungs) but what about the chemistry of it? The nature of pulling O2 from water is very different from pulling it from the air.
The tetrapod evolution article on wikipedia has a nice summary:
"In order for the lungs to allow gas exchange, the lungs first need to have gas in them. In modern tetrapods, three important breathing mechanisms are conserved from early ancestors, the first being a CO2/H+ detection system. In modern tetrapod breathing, the impulse to take a breath is triggered by a buildup of CO2 in the bloodstream and not a lack of O2. A similar CO2/H+ detection system is found in all Osteichthyes, which implies that the last common ancestor of all Osteichthyes had a need of this sort of detection system.
The second mechanism for a breath is a surfactant system in the lungs to facilitate gas exchange. This is also found in all Osteichthyes, even those that are almost entirely aquatic. The highly conserved nature of this system suggests that even aquatic Osteichthyes have some need for a surfactant system, which may seem strange as there is no gas underwater. The third mechanism for a breath is the actual motion of the breath. This mechanism predates the last common ancestor of Osteichthyes, as it can be observed in Lampetra camtshatica, the sister clade to Osteichthyes.
In Lampreys, this mechanism takes the form of a "cough", where the lamprey shakes its body to allow water flow across its gills. When CO2 levels in the lamprey's blood climb too high, a signal is sent to a central pattern generator that causes the lamprey to "cough" and allow CO2 to leave its body. This linkage between the CO2 detection system and the central pattern generator is extremely similar to the linkage between these two systems in tetrapods, which implies homology."
We can look into the genetics as well, covered a bit in this post on the inner ear and the genetics involved. I will paste a portion below:
Fish have what is known as a Lateral Line along both sides to detect movement, vibration, and pressure gradients in the surrounding water. The Lateral Line is composed of neuromasts (small receptors with hair-like projections which extend into a jelly-like sac ). The Lateral Line pits are found in the fossils of ancient fish as well, dating back hundreds of millions of years ago. The Lateral Line formation is controlled by the gene known as Pax 2, and the same exact gene is responsible for the formation of the inner ear in mammals and the varying levels of auditory ability in reptiles and amphibians (so all our tetrapods)
The receptors for BOTH these taxa appears in amphioxus in the form of hair-like epithelial cells and connecting neurons. Coincidentally, this organism is thought to be the precursor for all chordates.
To put it all more plainly: same gene that controls the formation of the lateral line (detecting prey, orientation, schooling) controls the formation of the mammalian inner ear (modern balance/hearing organ) and the ancestor of BOTH has the genes for the receptor type's origin.
Can we go back any further though?
Box jellyfish are incredibly "primitive" animals. They have a sort of ancient eye (unique to sea jellies), but certainly lack any type of ear or lateral line.
What do their genes say? They don't have Pax 2 (balance/hearing) OR Pax 6 (sight) but have a single gene for their primitive eyes that is a genetic mosaic of BOTH Pax 2 and Pax 6.
The implication here is that perhaps ancient cnidarians hold the key to the eventual duplication or point mutation that progenated Pax 2 and Pax 6 from the precursor mosaic.
So the genetics are in place by the time we reach the Sarcopterygians like Eusthenopteron, what about the physical form? The actual inner ear bones? Eusthenopteron's stapes is nearly in place, and by the time we meet the early amphibian Tulerpeton, the first inner ear bone is in place, although hearing would have been incredibly poor.
With this in mind, we essentially have directional selection and mutation taking advantage of open niches and the safety of a new habitat. Basically, Evolution working as is should.
Part 4: Examining the YEC Response
Up to bat is my personal go-to for YEC opinion: Answers in Genesis.
Thankfully there is an easily accessible article on their site, one originally posted in the Journal of Creation back in 2003. I was hoping that their primary page on the subject would be a bit more up to date, but we will analyze it anyways.
Paul Garner, Bsc Environmental Science, is Skeptical
The very first thing you should notice is the date that this paper was written, 2003, is a year prior to the discovery of perhaps the most important fossil of tetrapod evolution: Tiktaalik (2004). And even with that piece missing, there is quite a bit of floundering going on in this article (pun).
For instance, Garner presents a very misguided idea of what "intermediate" means in the context of a fossil form. Mind you, I have met very few Creationists (anecdotally) who will define what a transitional form would even look like. But here is what Garner has to say:
" Evolutionary theory might lead us to expect examples of intermediate structures, but there is nothing intermediate about, for example, the internal gills of Acanthostega, its lateral line system, or its limbs. They are fully developed and highly complex."
I wish someone would inform Garner that his idea on Evolutionary theory is incorrect. Evolutionary Theory predicts small morphologic changes accumulating over time thanks to natural selection and mutation. This means there will never be an intermediate species that is plagued by incumbent or lethal morphologies. This patently goes against the entire idea.
But let's check a more recent article shall we?
David Menton at it Again(ton)
Menton specifically covers tiktaalik here thankfully. But he doesn't go more than skin deep. Essentially Menton argues that tiktaalik is "still a fish" (something no one disputes) and that it couldn't walk on it's fins (which is a rather general statement).
Of course as we covered it is likely that if tiktaalik did move from different bodies of water it would be quite cumbersome, but not impossible. Similar to how modern mudskippers get about.
Menton's argument here boils down to calling tiktaalik a fish and mentioning coelacanth and lungfish to support the idea that fish can do the things tiktaalik can do. He doesn't dare go more than surface level on skeletal changes in the lineage over time.
But no AiG dive would be complete without the assertion that it's the evolutionary assumption that's the real problem.
Evolutionary Assumption = Bad
Here we see an unlisted author talk about Ventastega (not covered in this post). This is another transitional form somewhere between tiktaalik and terrestrial tetrapods. The article quotes the actual paper on the finding and rounds itself off with this:
" What the scientists in this study did not do, was examine alternative ideas about what Ventastega represents. For example, if we start from the Bible—that God created the earth and all animal kinds in six days about 6,000 years ago, then we would likely conclude that Ventastega, like Tiktaalik, represents both the amazing creativity and economy that God has used in the multitude of diverse designs He made. "
Essentially, Ventastega doesn't support evolution so long as you start with a worldview that already precludes evolution as a possibility.
I don't think I need to go into why this is not science in any shape or form. Beginning with a conclusion is never good in the world of science, be it biology, chemistry or physics.
Part 5: TL;DR
Tetrapod evolution is well documented in the fossil record and tracks morphologic change from aquatic sarcopterygians to terrestrial tetrapods. Criticisms of these fossils are poor to non existent and can be summarized as a slander of evolutionary theory simply due to it's implications. Valid criticisms point out we still have much to learn about this lineage, particularly in the realm of biochemical change, but this is classified as a lack of evidence in a facet of a well documented biological trend rather than what would be required for a YEC alternative: evidence to the contrary.
Thank you for reading!
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Transitional Species Handbook: Birds are the Definitively Living Descendants of a Lineage of Theropod Dinosaurs

7/13/2019

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(Book photographs are from Donald Prothero's "Evolution: What the Fossils say and Why it Matters" Second Edition All credit to this amazing Paleontologist for diagrams!)

Let's talk about the little dinosaurs we see every day.
The current near-universal consensus among paleontologists is that birds evolved from a group of dinosaurs known as Theropods.
YEC website Answers in Genesis, very much disagrees. This article was written by David Menton, who is not a paleontologist. He makes some very broad claims about the nature of our knowledge of bird evolution, most notably, that we do not have any feathered dinosaur fossils outside Archaeopteryx lithographica, which Menton insists is a true bird.
In the following post, we will explore the dozens of transitional forms between ancient scaled theropods and modern birds, including A. lithographica, who is definitively not a "true bird" as Menton suggests. Near the end we will touch on the molecular evidence as well.
Part 1: The Recipes for Non-Avian Dinosaurs and Modern Birds
In the realm of systematics, we have traits that classify organisms as one taxa or another. Below are the criteria of non-avian dinosaurs (in this case, theropods) and of Modern Birds. This is important to keep in mind as we examine the transitional forms because, as you will see, a neat line cannot be drawn to distinguish birds as a separate "kind" from their theropod ancestors.
Non-Avian Dinosaurs (Theropods)
  • Scales, or a mixture of feathers and scales
  • Non-keeled sacrum, and non-flexible shoulder joints
  • Unfused Pelvis
  • Comparatively heavier bones
  • Teeth
  • Grounded (not capable of flight)
  • Bony Tail
  • Gastralia (Unique to Sphenodons and Crocodilians, a rib attachment site)
Modern Birds
  • Feathers
  • Keeled sacrum and flexible shoulder joints
  • Fused Pelvis
  • Hollow, lightweight bones
  • Beaks without teeth
  • Primarily flight capable
  • Pygostyle
  • No Gastralia
Thus the evolutionary lineage should roughly look like so: non-feathered theropods > feathered non-avian dinosaurs > archaeopteryx > transitional birds > birds
Let's dive in!
(Some listed are species, some are genera)
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​Non-Feathered Theropod Likely Relative
Compsognathus (Late Jurassic): Almost entirely like a “normal dinosaur”. Like most theropods (but NOT living birds) Compsoganthus had many classic traits: Bony tail, skull with teeth, gastralia, midway bird/saurian hip, no feathers and theropod vertebra. BUT this animal also had a semilunate carpal (wrist) which is only seen in bird relatives and modern birds. This bone is actually the primary bone necessary in the downward flight stroke in avians today.
Semilunate Carpal
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​Non-Avian Feathered Theropods
Eosinopteryx (Late Jurassic): Non-Flight capable, but covered in down with proto primary feathers on wing it also has a semilunate carpal but lacked any other modern characteristics. Like most theropods, it had a non-fused pelvis and non-keeled sacrum but it is one of the first examples of feathers in theropods chronologically.
Anchiornis (Late Jurassic): Potentially a Microraptor relative, due to the proto-wings on both arms and hind legs, which had primary AND secondary feathers but no barbules so no flight. The wing is a mosaic of traits of theropod arm and the wing seen in archaeopteryx lithographica. Semilunate carpal present. The first to have more lightweight bones comparative to it's size.
Sinosauropteryx (Early Cretaceous): Covered with a coat of simple filament-like feathers whose coloration has actually been preserved in some specimens, indicating a reddish brown banded color for the animal. Excellent preservation has also shown this species has a more crocodilian-style respiratory system NOT as closely related to Archaeopteryx as some others to be covered, and is in fact likely a direct relative to compsognathus according to some paleontologists. Lightweight but not hollow bones and the ever present semilunate Carpal.
Protarchaeopteryx (Early Cretaceous): Well developed vane-style feathers from tail and a member of the oviraptors, (thus a step closer to Archaeopteryx). This animal had hollow bones and emergence of wishbone as well as the semilunate Carpal! NOT flight capable though, due to symmetrical feathering (modern birds with symmetrical feathers are not flight capable either, such as ostriches and emu.)
Sinorthosaurus (Early to Mid Cretaceous): Feathers most similar to modern birds thus far: a down like covering over the entire body, with arms almost converted entirely to wings. However, not flight capable, as the wings only have the primary barbules, not the secondary. Full wings combined with hollow bones and semilunate carpal indicate gliding may have been possible and small size as well as fossil location indicates arboreal lifestyle. Micro-cell analysis agian gives pigment to feathers, giving the animal a yellow-brown-black color. Sinorthosaurus had a wishbone and birdlike shoulder semilunate carpal and the first to exhibit a transitioning pelvis (to fused).
Caudipteryx (Early to Mid Cretaceous): Lineage of winged, feathered grounded dinosaurs with less advanced arm wings than Sinorthosaurus, however, primary feathers are arranged as in modern birds. "Primitive" body skeleton, but with hand and wrist transitioning towards archaeopteryx. Body is comparable to MODERN flightless birds with: uncinate rib processes,very few and reducing teeth, and a partially reversed first toe. Semilunate carpal and wishbone still present.
Beipaiosaurus (Early to Mid Cretaceous): Largest “for-sure” feathered dinosaur found with more advanced down feathers, arm-feathers (not quite wings though) and tail plume feathers 4-7 inches long. Beipaiosaurus had a large skull, lightweight bones and transitioning pelvis as well as semilunate carpals and a wishbone.
Microraptor (Early to Mid Cretaceous): Four winged dinosaur likely capable of at least gliding and likely flight due to the wings and skeleton. Primary and secondary flight feathers on large wings just like modern birds, semilunate carpal, advanced nearly perfectly modern bird shoulder, hollow and light bones. Flight was likely somewhat cumbersome however, in comparison to modern birds due to a not-QUITE modern shoulder, disallowing full modern motion. Theropod traits still present: teeth, claws and bony tail as well as a non-fully keeled sacrum and a partially fused pelvis
Zhenyuanlong (Early to Mid Cretaceous): The first to have a fused Sacrum (derived) but still has the unfused pelvis (primitive). Short arms (non-flight capable) but advanced wings, bringing questions as to the initial purpose of wings, and what may have driven their evolution. This species lack hindlimb feathers, has a semilunate carpal, wishbone, transitional pelvis and a tail that is analogous to Archaeopteryx lithographica.
Mei Long (Early to Mid Cretaceous): Feathered with down covering the body and somewhat "primitive" wings. Famous for death during sleep, and it's fossilized posture is identical to modern birds: neck tucked under the wing. This behavior further links birds and theropods. Mei Long had teeth, a bony tail (with feathered end), and was certainly grounded due to small arms/wings.
​Pictured Below are Caudipteryx and Sinosauropteryx
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Archaeopteryx lithographica: The Mosaic
This species is found in the Late Jurassic, notably earlier than some of these "less derived" theropods listed above. This is an excellent example of the branchy, bush-like nature of emerging adaptions in species. A trait may appear in several lineages and take entirely different directions. For instance, today the feathers in ostriches and emu are used for balance while running, not unlike Caudipteryx may have done.
The post is illustrating the nature of evolutionary trends. We see many different iterations of feather types, wing types and skeletal posture, but the trend is still the same: feathers initially evolved and persisted in theropod dinosaurs in a time period in which birds do not appear in the fossil record (Late Jurassic, "Modern Birds" show up in the Cretaceous). These new adaptions try all sorts of things in varying forms, but inevitably trend towards the successful morphology seen in modern birds.
So. What about Archaeopteryx. Is Menton correct? Is Archaeopteryx a "true bird"?
Absolutely not.
Let's do a trait check in shall we?
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​"True" Theropod:
  • Bony tail
  • perforated skull with teeth
  • theropod vertebra and shoulders
  • gastralia (rib formations exclusive to dinos)
  • A pelvis transitioning, but still more similar to that of a theropod
  • Theropod ankle with a short hallux
Archaropteryx lithographica:
  • Bony tail is present but SHORT compared to all other theropods
  • Teeth are present but un-serrated, unlike all other theropods, but skull is perforated and theropodian
  • Big toe is fully reversed (Modern Birds)
  • Wishbone, fused collarbone and modern bird shoulders
  • Unique modern feather symmetry suggesting more even flight
"True" Birds:
  • Pygostyle instead of bony tail
  • Non-perforated "avian" skull
  • NO teeth (egg teeth are not actual teeth, and are developmentally unique from true teeth)
  • Varying toe reversal
  • Wishbone, fused collarbone and shoulders
  • Modern feather symmetry
Is it a transitional form? Or a "True Bird"? Most certainly it is not the first species to wear feathers. Many theropods possessed these incredible structures prior to Archaeopteryx and some 50 species of decidedly non-avian dinosaurs had feathers (including the many mentioned).
The reason Archaeopteryx is transitional is supported by it’s many mosaic traits that place it as more advanced than those previously mentioned but still primitive to modern birds.
But enough about the transitional form poster child, let's continue onward.
Transitional Birds: Denizens of the Mezozoic
Rahonavis (Late Cretaceous): Indeterminate as to whether this animal is a member of avialae (birds) or a dromeosaurid, as arguments have been made for both. Still maintains many theropod traits including the tail, teeth, skull shape and some vertebral elements, but was certainly flight capable and had many of the derived traits as well (semilunate carpal, wishbones, fused skeletal elements etc). Some have proposed Rahonavis to be a relative of A. lithographica directly.
Confuciornis(Mid to Late Cretaceous): Most primitive bird relative to have a beak, however, skull was still predominantly theropodian in nature with nasals to the side of the snout etc.Although, the beak shape along with transitioning orbits are looking more modern. We see a pygostyle rather than bony tail but large claws tip the wings.
Sinornis (Mid to Late Cretaceous): More “advanced” than archaeopteryx in that it has a more modern bird-like pelvis, has teeth however, as well as clawed wings. Extremely modern skull lacking in most theropod perforations and capable of perching with modern bird derivations of the feet and legs. More modern blade-shaped shoulder blades as well, although we aren't quite at modern birds.
Ichthyornis (Late Cretaceous): Most modern bird on the list so far. This animal has almost entirely modern bird traits, save the teeth it still possesses. Was likely a sea-faring bird who utilized it’s teeth in hunting given fossilized location.
And upon losing these small teeth, we arrive at modern birds.
Looking at the pictures of these fossils will reveal what Menton seems to have entirely ignored or simply not researched: Dozens of theropods have feathers and Archeopteryx lithographica is certainly NOT a true bird.
But Menton has his reasons I suppose. While he could not have possibly seen the fossils (benefit of the doubt, lest we accuse him of flagrant dishonesty) he has a number of logistic problems in his proposal. Let's review and address them now.
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​Part 2: I know Why the Caged Archosaur Sings
Alternative title: Menton's Lament(on)
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1- Birds are Endotherms, Dinosaurs are Ectotherms
"Seemingly forgotten in all the claims that birds are essentially dinosaurs (or at least that they evolved from dinosaurs) is the fact that dinosaurs are reptiles. There are many differences between birds and reptiles, including the fact that (with precious few exceptions) living reptiles are cold-blooded creatures, while birds and mammals are warm-blooded. Indeed, even compared to most mammals, birds have exceptionally high body temperatures resulting from a high metabolic rate." -Menton
When one bisects a theropod bone, they find that the bone is immensely more similar to mammalian (endotherm) and avian (endotherm) bone than it is to that of modern reptilian ectotherms! UCMP researchers have been working on dinosaur bone histology (the thin-sectioning of bone to see its structure). And their work suggests that dinosaur growth rates are far more consistent with those seen in endotherms.
And more recent research seems to suggest most dinosaurs weren't ectothermic at all, but were actually mesoderms. Precisely what we would expect to see for an "intermediate" between birds and non-dinosaurian reptiles.
2- A Hugely Concerning Misnomer Misadventure ft. David Menton (and the AiG Gang)
alternative title: Bird hip/Lizard hip
" All dinosaurs are divided into two major groups based on the structure of their hips (pelvic bones): the lizard-hipped dinosaurs (saurischians) and the bird-hipped dinosaurs (ornithiscians). The main difference between the two hip structures is that the pubic bone of the bird-hipped dinosaurs is directed toward the rear (as it is in birds) rather than entirely to the front (as it is in mammals and reptiles). But in most other respects, the bird-hipped dinosaurs, including such bizarre creatures as the armor-plated ankylosaurs and the horned ceratopsian dinosaurs, are even less bird-like than the lizard-hipped, bipedal dinosaurs such as the theropods. This point is rarely emphasized in popular accounts of dinosaur/bird evolution." - Menton
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It is widely thought that birds evolved from Theropods, known “lizard-hipped” Dinos. This is a bit of a misnomer, and the answer to why lies in the ornithischians. “Bird” hips actually evolved twice, a concept called Convergent Evolution. So lizard-hipped theropods eventually diverged a group with functional bird hips, and simultaneously, ornithischians walked the earth with their own “bird” hips.
Why does Menton not know this? Why does he assume that the initial bird-hipped dinosaurs evolved into birds, and a type into google would have cleared this up?
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3- A Theropod in the Hand is worth Two in the Bush
alternative title: The Digit Issue
"One of the main lines of evidence cited by evolutionists for the evolution of birds from theropod dinosaurs is the three-fingered “hand” found in both birds and theropods. The problem is that recent studies have shown that there is a digital mismatch between birds and theropods. Most terrestrial vertebrates have an embryological development based on the five-fingered hand. In the case of birds and theropod dinosaurs, two of the five fingers are lost (or greatly reduced) and three are retained during development of the embryo. If birds evolved from theropods, one would expect the same three fingers to be retained in both birds and theropod dinosaurs, but such is not the case. Evidence shows that the fingers retained in theropod dinosaurs are fingers 1, 2, and 3 (the “thumb” is finger 1) while the fingers retained in birds are 2, 3, and 4" -Menton
This problem seems to be a bit of a semantic one as there is no ontogenical (developmental) basis to definitively state which digits are which on a theropod hand (because no non-avian theropods can be observed growing and developing today), the labelling of the theropod hand is not absolutely conclusive. Basically, no one agrees because they aren’t even sure they’re talking about the same thing. Also this is not one of the main lines of evidence.
4- David Menton versus the Respiratory System
"While fossils generally do not preserve soft tissue such as lungs, a very fine theropod dinosaur fossil (Sinosauropteryx) has been found in which the outline of the visceral cavity has been well preserved. The evidence clearly indicates that this theropod had lung and respiratory mechanics similar to that of a crocodile—not a bird.6 Specifically, there was evidence of a diaphragm-like muscle separating the lung from the liver, much as you see in modern crocodiles (birds lack a diaphragm). These observations suggest that this theropod was similar to an ectothermic reptile, not an endothermic bird." -Menton
Sinosauropteryx is listed as an example to refute the avian lung/air sac appearance as well as flight, given it had feathers and small arms. But sinosauropteryx is a compsognathid, and not a true member of the bird lineage. It is an example belonging to the aforementioned group of non-avian dinosaurs which had feathers but never yielded birds. Additionally, Large meat-eating dinosaurs had a complex system of air sacs similar to those found in modern birds, according to an investigation led by Patrick M. O'Connor of Ohio University. In theropod dinosaurs (carnivores that walked on two legs and had birdlike feet) flexible soft tissue air sacs likely pumped air through the stiff lungs, as is the case in birds. "What was once formally considered unique to birds was present in some form in the ancestors of birds", O'Connor said
5- Feathered Folly
alternative title: David Menton pretends feathered dinosaurs don't exist and no one knows have feathers evolved
"Structures described as “protofeathers” in the dinosaur fossils Sinosauropteryx and Sinithosaurus are filamentous and sometimes have interlaced structures bearing no obvious resemblance to feathers. It now appears likely that these filaments (often referred to as “dino-fuzz”) are actually connective tissue fibers (collagen) found in the deep dermal layer of the skin. Feduccia laments that “the major and most worrying problem of the feathered dinosaur hypothesis is that the integumental structures have been homologized with avian feathers on the basis of anatomically and paleontologically unsound and misleading information.”
Firstly, see the above list to examine the numerous feathered dinosaurs Menton doesn't cover. And ALSO note something odd: Mention suggests Sinosauropteryx's feathers are simply collagen. But we can chemically examine these structures enough to discern their color using methods for feathers, a structure made of keratin. Collagen cannot be, for instance, red with brown bands, yellow or black. At least not any that I have seen.
"If birds evolved from dinosaurs or any other reptile, then feathers must have evolved from reptilian scales. Evolutionists are so confident that feathers evolved from scales that they often claim that feathers are very similar to scales. The popular Encarta computerized encyclopedia (1997) describes feathers as a “horny outgrowth of skin peculiar to the bird but similar in structure and origin to the scales of fish and reptiles.”12
In actual fact, feathers are profoundly different from scales in both their structure and growth. Feathers grow individually from tube-like follicles similar to hair follicles. Reptilian scales, on the other hand, are not individual follicular structures but rather comprise a continuous sheet on the surface of the body. Thus, while feathers grow and are shed individually (actually in symmetrically matched pairs!), scales grow and are shed as an entire sheet of skin.
The feather vane is made up of hundreds of barbs, each bearing hundreds of barbules interlocked with tiny hinged hooklets. This incredibly complex structure bears not the slightest resemblance to the relatively simple reptilian scale. Still, evolutionists continue to publish imaginative scenarios of how long-fringed reptile scales evolved by chance into feathers, but evidence of “sceathers” eludes them." -Menton
As it turns out, the evolution of feathers from scales is not all that complicated. Essentially, elongated filaments appeared first on Theropods, followed by down and eventually body and flight feathers. This seems like a complicated process, but scales develop from a structure called placode. This structure, when “on” genetically, produces scales, but if “off” a ring of fast-growing cells on the top of the placode builds a cylindrical wall that becomes a bristle. We see in birds the bristle undergoes development and becomes a fully fledged feather66. But the point is that once a filament is evolved via scale mutation, feathers are not far off! This is very contradictory to Dr. Menton’s idea that the structures are vastly different, and yet this is a well founded and observable phenomenon. How so? Birds still have scales that remain “on” genetically on their legs!
Part 3: To Briefly Mention Mary Schwietzer
In all the hubub Creationists make about Schwietzer's work, they seem to ignore one of the major aspects of her findings regarding "soft" tissue in fossils. She discovered medullary bone in her female Tyrannosaur. This is was previously found ONLY in modern gravid birds.
Once again linking even the most classically "scalely" theropods to the sparrow outside your window or the terrifying Canadian geese heckling you on your daily walk.
TL;DR
Modern birds are the descendants of theropod dinosaurs, and both are considered archosaurs. This is known through the dozens of transitional forms, molecular data and behavioral similarities preserved taphonomically.
Normally, I would list here how this could be refuted, but I don't really think it can be done in this instance. To refute this you would need to find direct evidence for Progressive Creation, and I am not exactly certain how that could even be done.
Besides, rejecting such a fine example of evolutionary lineage and molecular support is for the birds anyways.
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Transitional Species Handbook: Cetaceans (Whales and Dolphins) are Definitively the Descendants of Terrestrial Artiodactyls (Even-Toed Ungulates)

7/13/2019

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Cetaceans roam our oceans today as both immense predators and gentle giants. From the tiny Vaquita to the enormous Blue Whale (the largest animal currently known to inhabit our planet in all it's history) these marine mammals occupy some of the niches left open by the extinct sea-going reptiles of old. They began this journey some 50-55 million year ago as a terrestrial hoofed mammal no larger than a housecat.
What drove this return to the sea? What evidence do we have to support it? How could it occur so quickly?
This post aims to document the evolutionary transitions of cetaceans from their humble terrestrial beginnings to the majesty of the great organisms roaming our seas today, as well as examine the genetic and embryologic evidence for this journey. Finally, we will examine some of the qualms YEC sites have with the entire idea.
Key Sources:
Comparing Skeletal Structures (Excellent)
On Joint Transitions Specifically (Site is a bit messy)
Vestiges (Concise)
Genes Etc (Great)
Theistic Evolution Site (Informative)
Basic Wiki (For the Lazy)
Let's get started!
Part 1: Feet and Fins
As usual with these posts, we must identify what separates our "starting" species or genus from our "ending" species or genus. It is important to keep in mind that our classifications of organisms is an attempt to categorize a gradient of ever-changing forms; it's somewhat arbitrary. That said, these classifications serve to help us observe evolutionary trends.
Although first we must define some of the aspects of our modern cetacean's classification.
Modern cetaceans are apart of the order Artiodactyla, or, the even-toed ungulates. These are hoofed animals who bear weight on an even number of toes. But they have other defining characteristics, such as their scapula shape and unique joints (trochlear hinges) built for maintaining stability at high speeds.
The latter, is why we classify cetaceans in artiodactyla: They have hind limbs that are stunted in development, but display artiodactyl characteristics: the trochlear hinges (astragalus)
These traits are absolutely unique to artiodactyls, and all modern animals classified as such possess them: including the cetaceans.
Which leads us to out most basal form: Indohyus.
Indohyus lived some 48-55 million years ago, and has all the traits one would desire in an artiodactyl: four limbs under the body, a rostral pair of nostrils, hooves with trochlear hinges, mobile scapula, a short skull, conical tail, bulky shape and not much else. Except... it does have a unique trait: the involucrum. This is a bony middle ear structure which is today, UNIQUE to cetaceans and no other animal. Additionally, Indohyus has bone density similar to Hippos, the most genetically close relative to cetaceans in living organisms.
This is why we start with Indohyus:
Indohyus Traits
  • Four limbs below body
  • nasal opening at end of snout
  • bulky non-streamlined shape with weight-bearing pelvis
  • short skull
  • terrestrial
  • Heterodont Teeth
  • Conical tail
  • Involucrum
Modern Cetacean Traits
  • Two distinguished fins no hindlimbs (save the non-weight-bearing pelvis and reduced femur)
  • blowhole (dorsocranial nasal opening)
  • streamlined shape
  • elongated skull
  • aquatic
  • Monodont teeth
  • tail flukes
  • Involucrum
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Part 2: The Whales of this Tale
The evolutionary change takes place over 13-15 million years. This seems like a short amount of time, but this will be addressed later. First lets take a look at the organisms in this lineage.
As usual, it is important to remember the bushy nature of life, taphonomy and fossilization. Even though we have what appears to be a concise and stepwise transition of forms, species can persist past their progeny's emergence and forms are likely not truly direct, but rather depict a gradient of traits appearing and overall evolutionary trends.
If this is not properly understood or outright rejected there is not much point in further discussion.
This is seen in practice when we meet the "next" on the line, whose fossil exists before and alongside Indohyus:
Pakicetus: 52-48 MYA: More wolf-like, Pakicetus has a narrower snout, and has lost the characteristic dental trait of mammals: specialization of the teeth (heterodontia), and a deducible dental formula. Instead, it has the conical teeth most carnivorous cetaceans have (monodontia).
Now this animal has webbed feet rather than hooves. How do we know it's related to indohyus? It has the ARTIODACTYL KNEE AND ANKLE, complete with troclear hinges. This is stunning, because no carnivorous animal today HAS artiodactyl knees/ankle... but all cetaceans have the remnants of them. Pakicetus ALSO has the involucrum. It's bone chemistry suggests a freshwater lifestyle with excursions into, but not permanent living in, the water.
Currently it is suggested that Pakicetus and Indohyus shared a common ancestor with an involucrum, and not the the latter begat the former. This is especially due to the existence of the Mesonychids: hoofed carnivores who also lived in the Eocene. These organisms are in a similar position as Pakicetus: hoofed animals with toes (hoofs becoming a sort of nail analogue). It has been proposed that the Mesonychids gave rise to the pakicetids, but molecular evidence has rejected this hypothesis.
The reason Indohyus is included however is due to it's possession of the involucrum which is unique to cetaceans and no current terrestrial life making it a relative, if perhaps a more distant offshoot.
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​Ambulocetus: 47.8-41.3 MYA arrives on the scene next, Mid-Eocene, and resembles a large mammalian crocodile. Bone analysis shows a delta-lifestyle with some time in saline and some in freshwater. It also has the artiodactyl joints (TH) and the involucrum, but unlike pakicetus, ambulocetus is beginning to grow sluggish on land. It's hindlimb structure is just not quite as conducive to terrestrial locomotion.
In comparison to the pakicetids, these guys have more robust feet and a more flexible spine. They also have transitioning orbits (positioned dorsally but not yet frontated) precisely like current amphibious mammals such as hippos. This is ideal for peering out of the water while submerged!
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​Rodhocetus 48.6-40 MYA AGAIN have the involucrum and the artiodactyl joints. This guy has a new cetacean-only trait in the making: four of it's sacral vertebra are partially fused. In cetaceans today, ALL the sacral vert. are fused. This animal has a bone density of saltwater exclusivity, and has nostrils beginning to move up dorsally. This is not surprising, as we now have the pressure to breathe without the effort a rostral nostril would require.
This organism likely lived alongside Ambulocetus for a while, especially since they occupied different niches. Species exist in both the rodhocetid and ambulocetid genera that actively display the variety even within these larger categorizations.
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​Dorudon: 40-33.9 MYA. Still, involucrum and artiodactyl joints. Now the sacrum is fully fused as well, and the nostrils are MORE dorsal than before. Eyes have moved frontally now, and some paleontologists have suggested the existence of tail flukes. Hind limbs are still "useful" in and of themselves, but gone are the webbed feet: it has flippers. Wholly marine, dorudon has all the traits of a modern cetacean save the fully dorsal blowhole, fully developed melon organ, fully interal hind limbs and large brain.
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​Basilosaurus 40-35 MYA is enormous and nearly a full cetacean. It has all of Dorudon's traits (including that involucrum and the artiodactyl knee/ankle) as well as it's general streamlined shape. The blowhole is even more dorsal in comparison though, and the hind flippers are all but internal. The braincase is still somewhat small from the social cetaceans of today though. But for intents and purposes, this is a near-cetacean.
Additionally are the Remingtoncetids (47-43 MYA) who are considered relatives of modern cetaceans, but as offshoots or "cousins". These strange beasts resembled mammalian gharial with narrow muzzles stacked with thin teeth. They have been found with the protocetids (rodhocetids) as well as with ancient crocodiles, sirenians and catfish. Never with indohyus, pakicetus or ambulocetus who predate this genera in some cases and vary in habitat in others. They also posses the involucrum and artiodactyl joints.
Thus in the lineage for cetaceans a rough separation can be made:
Basal hoofed Goup
Indohyus and perhaps Indohyus and Pakicetus's CA
Most Basal Cetaceans
Pakicetids and Ambulocetids
Protocetids and Remingtoncetids
Rhodocetus and the Remintongtoncetids
Basal Obligate Marine Whales
Dorudon and Basilosaurus
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Part 3: The Timeline (and molecular data)
Timetree.org allows one to pull general timelines from compiled molecular data (How they do it). This source backs up the timeline for cetacean proliferation over the course of 13-15 million years. This kind of change seems quite large over that period of time, but empirically it is supported by mutation rates and transitional fossils.
The same site, among many others, support our own evolution from the chimpanzee-like S. tchadensis in a mere 7-9 million years.
What these two events (and many others of "fast" evolution) have in common is that they are seemingly spurred by environmental change. In our own lineage this resulted from the East African Rift creating a sparse savanna not idea for arboreal quadrupeds. And in the cetaceans we see the opening of the niches left by the marine reptiles.
This is seen in modern times as well with the Pod Mrcaru Lizards.
Essentially, individuals from a parent population on one Italian island were relocated to a new island (5 pairs, so 5 males and 5 females) back in 1971. Researchers then checked in on them 50 years later, and found that the lizards had undergone rapid evolutionary change in response to a new food source.
The lizards on the parent island were insectivorous, but the new population had switched to herbivorous habits. The new lizards had adaptions for herbivory seen in only 1% of all lizards: cecal valves, hindgut bacteria for digesting foliage and a new skull shape built for managing leaf eating. All in just 50 years!
Selection becomes highly directional when there is enough environmental pressure is the long and short of it.
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Part 4: It's all Genes to me
If evolutionary theory in this case is valid, than the genes will tell us. Since evolution works by tweaking precursor structures (even at the molecular level), we should find remnants of cetacean's terrestrial past in their genome. The first place to look would be for the formation of hindlimbs in embryological development, but we will go over that in embryology.
Shubin goes over this very topic in his book "Your Inner Fish". He notes that all mammals have some 3% of their total genome dedicated to odor detection, including cetaceans. But in these animals, who have over one thousand genes dedicated to smelling and picking up scents in the air (just like all mammals), every single gene is non-functional.
As a result, they also lack a proper gustatory sense (taste), and some believe this contributes to the proportionally high number of cetaceans ingesting toxic debris.
Bone mass has also been identified genetically, and found to have been positively selected for:
" Comparative genomic analyses of cetaceans and their terrestrial relatives provided several novel insights into the distinct evolutionary scenarios of adaptation to a fully aquatic lifestyle. Genes associated with oxidation–reduction and immune process were found to be accompanied by pseudogene copies. Genes under positive selection in the cetaceans were related to reproduction, keratin protein, learning, and energy turnover. This was interesting given their special lifestyle compared with other mammals. Our study also documented the bone microstructure across mammals and marine mammals, and for the first time, revealed the benefit of using a phylogenetic comparative approach to study the evolution of bone compactness. Our findings offer valuable information on genes critical for adaptation to aquatic life of mammals in diverse environments. "
Just these two examples pose some large questions to the proposal of intelligent design and progressive creationism.
Part 5: Embryology
Equally as fascinating as the genes is the development. Just as we as humans bear some of the traces of our fore-bearers in-utero, so do cetaceans.
Modern cetaceans undergo a stage in their embryological development where they begin to develop hindlimbs, just as they do their forelimbs. This is what is considered business as usual. But the development of the hindlimbs terminates soon after the buds form, and they waste away until only the pelvis and some femoral remnants are left (as they are first to form).
You can find these stages pictured here by actual cetacean embryos.
What has appeared to have happened is that a mutation halts the development at a predetermined point each time a pup develops. Studies have pinpointed what happens here : "... cetacean embryos do initiate hind-limb bud development. In dolphins, the bud arrests and degenerates around the fifth gestational week. Initial limb outgrowth in amniotes is maintained by two signaling centers, the apical ectodermal ridge (AER) and the zone of polarizing activity (ZPA). Our data indicate that the cetacean hind-limb bud forms an AER and that this structure expresses Fgf8 initially, but that neither the AER nor Fgf8 expression is maintained."
Some Creationists have proposed the existence of the pelvis is for copulatory purposes in the male cetaceans, and it may well be, but this is not an explanation for the hindlimbs themselves, nor the convoluted process that forms both.
Part 6: YEC perspective
As a forward here, much of these arguments boil down to "You have Pakicetus and Ambulocetus but wheres the transition between those two!" and "Not enough Time".
ICR starts us off with: "Scientific Roadblocks to Whale Evolution"
" A number of land animals have been proposed as the whale's ancestor, including Darwin's bear, grazing ungulates, wolf-like carnivores (Mesonyx), and the hippopotamus. In each case the morphological differences are significant. If whales (cetaceans) did evolve from land mammals, they did so at an unbelievable rate, accruing an amazing number of "beneficial" mutations and adaptations."
This is appealing to the issue of time, and also never actually mentions the proposed first cetacean: Pakicetus. It goes so far as to suggest Ambulocetus the following paragraph:
"The skeletal features would need to change radically, as well as the physiology (the collective functions of an organism). For example, the supposed early "whale," Ambulocetus, drank fresh water probably throughout its life "50 million years ago," and Indocetus was a saltwater drinker "48 million years ago." This means that in perhaps three million years there had to be an extreme change in the physiology of these creatures."
This article was written in 1998 and pakicetus was found in 1981 so I'm not sure why it is never mentioned. Additionally this salinity "problem" ignores the analysis of ambulocetus's bones, which show a clear brackish lifestyle in between pakicetus's more freshwater and rodhocetus's more marine.
It goes on to complain about maintaining heat in the cold recesses of deepwater, apparently ignorant of both blubber and polar animals who possess it in favor of creating an issue with homeostasis that is not problematic.
AiG is also out and about with "Fossil Evidence of Whale Evolution"
This involves Terry sending a message to talkorigins which is both brave and malinformed. This article doesn't simply pose nonpromblematic issues, but presents a very flagrant misunderstanding of what it is trying to refute. Some highlights:
" Certainly there has been diversification within the whale kinds (see what I mean about “kind” in point 2 below). But how do you know that what you have been told about certain fossils is really evidence of the evolution of whales from some land animal? How do you know that the fossils can be arranged in a nice neat record of successively younger rocks? You are not a paleontologist and didn’t dig up the fossils. Given the statement by Raup about horse fossils (in the first part of this article), I certainly will not trust evolutionist claims without careful examination. "
The fossils are arranged according to the age of the rock they are found in (via radiometric dating, a very accuratemethod of telling the age of igneous rock). Because these fossils can be separated by general age, the trend of the emergence of traits can be observed, creating a succinct means of examining change over time.
I do appreciate the "You weren't there" aspect of "historical science" being applied to literally digging up a fossil, followed by a warning not to trust "evolutionists". Frequently AiG likes to bring up paleontologic hoaxes, unaware they are quite rare in comparison to hoaxes of artifacts of historical antiquity and art.
"I have no idea what you mean by saying, “‘Arrival of the fittest’ is of course a biological question and has little to do with evolution.” Isn’t evolution a hypothesis about the origin of biological life? Do you mean that the origin of the first living cell is a question that has little to do with evolution? If so, I disagree. It has everything to do with it. If evolutionists can’t explain how the first living, reproducing cell came into existence by time, chance, and the laws of nature working on non-living matter, then the theory of evolution is dead. Natural selection and mutations can only work on living, reproducing organisms."
Dreadful. This false equivalency is why so many secular (and religious but conventional) scientists are quick to be wary of Creationists. Abiogenesis is not evolution, and it simply doesn't matter how much Terry misunderstands this or blatantly disagrees because it is a hard and fast definitions game.
" Actually, time is not the hero of the plot, but the villain. Time doesn’t create anything. With the help of the Second Law of Thermodynamics it destroys things. The more time we have, the more mutations destroy genetic information, as Spetner’s and Sanford’s books above persuasively show."
A misunderstanding of what constitutes "new" genetic information (for which AiG lacks a definition for anyways) in conventional science, and another misuse of the 2nd Law. The Earth is not a closed system Terry!
"Evolution and millions of years hopelessly fail to explain our world. They don’t explain the origin and diversification of genetic information, the origin of incredible design in living things, and the origin of human language, which is vastly different and superior to any animal communication. They don’t explain the fossil record or the thousands of feet of sedimentary rock layers (some of which extend for tens of thousands of square miles). They don’t explain the orderly design of the solar system. And while evolutionists assume the validity of the laws of nature, their evolutionary ideas cannot explain why those laws are valid. And the evolutionary view provides no basis for purpose and meaning in life or any absolute morality."
I think this is something of a "cart before the horse" scenario given he's already fighting a version of evolutionary theory that does not exist. But I would love to see Terry tackle the issues geology, cosmology and paleontology present to his worldview once he's gotten a grasp on what he's actually against.
Conclusion/ TL;DR
Through 13-15 million years of geologic time the transition of terrestrial hoofed mammals to the cetaceans of today is well documented in transitional fossils. The persistence of identifying morphologic traits (involucrum and artiodactyl joints) supports this notion along with current molecular data, genome maps and embryology.
Critics tend to focus on the intangible (prove specific mutation X in a lab) or the non-problematic (timescale), and in the context of this post are not educated in the area in which they are critiquing.
If you have any of your own critiques feel free to voice them, but be aware I am certainly not an expert and this information is simply compiled opinions and data by people who are.
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Transitional Species Handbook: Humans are Definitively the Descendants of A Lineage of Ape-Like Ancestors and Thus We are Still Apes (Hominids)

7/13/2019

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​It is difficult to find a more scrutinized facet of Evolutionary Biology than that of our own evolutionary history. This is due to our inherent desire to feel apart from nature as it's master, rather than acknowledge our original spot seated firmly in the middle of the Serengeti food chain. There is a humbling that must occur to see oneself in the ancient apes of yesterday, scraping about in the dust of the East African Rift Valley, and yet this past of ours it written in our very bones: from how we walk to how we talk.
The following post will explore this journey from the first true hominid to ourselves, and examine why our evolution is irrefutable morphologically, paleontologically, genetically and archeologically. I will try my best not to romanticize, but this is a topic I am very passionate about so forgive me if I get a bit flowery.
First, let's quote our friends at Answers in Genesis to set the scene of Human Evolution denial before we attempt to prove it as a fact:
“Clearly, there is nothing suggesting a transition between apes and humans. All we can see from the fossil record is either apes, or humans. Saying something is a human ancestor just because its an extinct “kind” of ape, doesn’t make something a human ancestor.”
The path to humanity from the first mammal begins with the plesiadapiforms, specifically, a former resident of Montana named Purgatorius. The development of the Old world monkeys (Cercopothecoids) which led to apes will not be discussed as the topic of discourse is strictly from apes to humans, not old world monkeys.
The first relative, and the original perpetrator of habitual (occasional) bipedalism is found in the East African Rift, in what is today Kenya, Tanzania and Ethiopia. The East African Rift is the boundary between two tectonic plates that sprawl across Africa and India, which now separate the lush tropical rainforests of West Tanzania and the Congo from the flat Serengeti that dominates where our ancestors first climbed down from the trees out of necessity. So who were these ancestors? There are some 17 species of well documented Hominids. 20, if you count some of the less supported fossils.
Let's Dive in!
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Part 1: The Recipes for Genus Sahelanthropus (oldest ape -like ancestor) and Homo sapiens
Sahelanthropus tchadensis
  • Low encephalization (Brain case size: 300-350 cm SQ)
  • Habitual Bipedality (No valgus knee, opposable toes, Foremen Magnum more behind the skull, Shorter Hindlimbs)
  • Dentition (2:1:2:3 but no parabolic palate and large canines)
  • Face morphology (High Prognathism, reduced zygomatics, saggital crest, no forehead, heavy browridge)
  • Reduced Sexual Dimorphism (This will rise with the Australopiths and reduce again in Homo)
  • No tool use
  • No culture
Homo sapiens
  • High encephalization (Brain case size: 1200-1300 cm SQ)
  • Obligate Bipedality (Valgus knee, Bowl shaped Pelvis, Inline Big toe, Ventral Foremen Magnum, Longer Hind Limbs)
  • Dentition (2:1:2:3, Parabolic Palate, Reduced Canines)
  • Face Morphology (Reduced Prognathism, Sharper Zygomatics, Loss of Saggital Crest, Elongated Forehead, Brow Ridge Reduction)
  • Reduced Sexual Dimorphism
  • Tool use (Fire, Stone Tools, etc)
  • Culture (Cave Art, Jewelry Etc)
Part 2: The Players in the Game (Brain Cases in cm SQ)
The Early Hominids
3 Genera
Sahelanthropus
Orrorin
Ardipithicus (Kadabba and Ramidus)
Highly variable
Bipedal at least habitually (more than chimpanzees and bonobos)
Dentation microwear indicates frugivory and some omnivory
Mostly ape-like
Sahelanthropus tchadensis (7 MYA):
Brain case: 300-400
Sahelanthropus tchadensis is one of the oldest known species in the human family tree. Walking upright may have helped this species survive in diverse habitats, including forests and grasslands, although it definitely spent time in the trees.
This species had a combination of ape-like and human-like features:
Ape-like features included a small brain (even slightly smaller than a chimpanzee’s), sloping face, very prominent browridges, and elongated skull.
Human-like features included small canine teeth, a short middle part of the face, and a spinal cord opening underneath the skull instead of towards the back as seen in non-bipedal apes. The spinal cord opening (foremen magnum) is what tells us this animal was at least partially bipedal, although it was likely cumbersome at times due to no in-line big toe!
Found in Chad
Orrorin tugenensis (6 MYA)
Brain Case: 300-400
Living around 6 million years ago, Orrorin tugenensis is the one of the oldest early humans on our family tree.
Individuals of this species were approximately the size of a chimpanzee and had small teeth with thick enamel, similar to modern humans.
he most important fossil of this species is an upper femur, showing evidence of bone buildup typical of a biped - so Orrorin tugenensis individuals climbed trees but also probably walked upright with two legs on the ground similar to Sahelanthropus.
Orrorin is at the base of the human family tree, and has more ape-like features than human-like ones -- except that it walked upright on two legs when on the ground.
Found in Tugen Hills, Kenya
Ardipithicus kadabba (5.8-5.2 MYA)
Brain Case: 300-400
Ardipithecus kadabba was bipedal (walked upright), probably similar in body and brain size to a modern chimpanzee, and had canines that resemble those in later hominins but that still project beyond the tooth row.
One bone from the large toe has a broad, robust appearance, suggesting its use in bipedal push-off.
Yohannes Haile-Selassie discovered 11 specimens from at least 5 individuals
Found in Middle Awash in Eithiopia
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​Ardipithicus ramidus (4.4 MYA)
Brain Case: 350-400
The foot bones in this skeleton indicate a divergent large toe combined with a rigid foot – it's still unclear what this means concerning bipedal behavior. The pelvis, reconstructed from a crushed specimen, is said to show adaptations that combine tree-climbing and bipedal activity.
The discoverers argue that the initial ‘Ardi’ skeleton reflects a human rather than a Pan ancestor as Ardi was not chimpanzee-like (bipedality, low sexual dimorphism and higher encephelization).
A good sample of canine teeth of this species indicates very little difference in size between males and females in this species. Ardi’s fossils were found alongside faunal remains indicating she lived in a wooded environment.
Discovered in Middle Awash Eithiopia
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​The Australopiths (Savannah Bipeds)
Likely gracile with larger overall size than chimpanzees.
Larger brain size (even accounting for overall size) than chimpanzees
Dentation is megadont and the palate is midway between human and chimpanzee in regard to parabolic shape. Molars getting larger.
Arms still longer than legs, foremen magnum continuing to move ventrally.
More bipedal than the ardipiths, but still some time in trees.
Thick tooth enamel (a human trait)
Still apelike development (rapid infant growth)
Australopithicus anamensis (4.2-3.9 MYA)
Complete enough brain case not found, brain cc unknown
Australopithecus anamensis has a combination of traits found in both apes and humans.
The upper end of the tibia (shin bone) shows an expanded area of bone and a human-like orientation of the ankle joint, indicative of regular bipedal walking (support of body weight on one leg at the time). Long forearms and features of the wrist bones suggest these individuals probably climbed trees as well.
Found in Kanapoi, Kenya
Australopithicus afarensis (3.8-2.9 MYA)
450-500 cc brain
Au. afarensis had both ape and human characteristics: members of this species had apelike face proportions (a flat nose, a strongly projecting lower jaw), and long, strong arms with curved fingers adapted for climbing trees. Despite climbing, big toe is almost completely in line, indicating frequent time on the ground as well.
They also had small canine teeth like all other early humans, and a body that stood on two legs and regularly walked upright with a valgus knee similar to modern man.
Their adaptations for living both in the trees and on the ground helped them survive for almost a million years as climate and environments changed.
Remains from over 300 individuals have been found, and indicate heavy Sexual Dimorphism (perhaps in line with modern chimpanzees)
First found in Hadar, Eithiopia (Lucy)
Australopithicus africanus (3.3-2.1 MYA)
480-500 cc brain
Au. africanus was anatomically similar to Au. afarensis, with a combination of human-like and ape-like features.
Compared to Au. afarensis, Au. africanus had a rounder cranium housing a larger brain and smaller teeth, but it also had some ape-like features including relatively long arms and a strongly sloping face that juts out from underneath the braincase with a pronounced jaw.
Like Au. afarensis, the pelvis, femur (upper leg), and foot bones of Au. africanus indicate that it walked bipedally (valgus knee and inline big toe), but its shoulder and hand bones indicate they were also still well adapted for climbing.
Found in Southern Africa (potentially a migratory branch of A. Afarensis)
Our Paranthropine Cousins (The "Robust" Australopiths)
Known as the “robust” Australopiths
Brain size slightly larger than their Australopith cousins
Huge megadont teeth (primarily molars)
Massive zygomatics and sagittal crests in males
Despite being a cousin (and not direct relative) to us, the hominid trends continue: Bipedal (ventral FM), reduced canines, ^ brain, ^ size, almost inline big toe, valgus knee and bowl-trending pelvis.
Differences that make them likely cousins rather than relatives: HIGH sexual dimorphism (males were much larger), Huge zygomatics and sagittal crest, massive molars suggesting a heavily plant based diet.
Due to character restraints, the Paranthropines will not be covered in depth. There are three well known species, P. aeithiopicus, P. robustus and P. Boisei (2.7-1.2 MYA)
They are fascinating though! Check them out and perhaps we can cover them in another post.
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​Homo habilis (2.4-1.6 MYA)
Brain case: 550-700
The first animal classified as genus Homo, rather than an australopithicine. It has reduced prognathism, smaller canines and a smaller brow ridge. It's small, like it's predecessors, but it's body ratio is trending towards human, although the arms are still "too long". It was certainly obligately bipedal, due to it's knees and ventral foremen magnum. H. habilis is found frequently with stone tools. Sexual dimorphism is shrinking again, and long species reign shows a broad range of encephilization. Ape like traits include brain case, face morphology (brow ridge and small s. crest still present, prognathism reduced but still accounted for).
Homo rudolfensis (1.9-1.8 MYA)
Brain Case: 775
Considered unique from H. habilis, but only recently so. It has unique features not within species variety in the constraints of natural selection: "larger braincase, longer face, and larger molar and premolar teeth. Due to the last two features, though, some scientists still wonder whether this species might better be considered an Australopithecus, although one with a large brain!" If H. rudolfensis is a transitioning form of H habilis, it likely used tools as well although to my knowledge no direct tools have been found with it.
Homo georgicus (1.7 MYA)
Brain Case: 600
is somewhat controversial in it's ranking. It has a small braincase size for Homo and more "old traits": showing a species primitive in its skull and upper body but with relatively advanced spines and lower limbs, providing greater mobility. They are now thought to represent a stage soon after the transition between Australopithecus and Homo erectus, and have been dated at 1.8 million years before the present. Tool use is observed both in finding tools with the specimens and cuts in animals bones found alongside specimens.
Homo ergaster (1.9-1.5 MYA)
Brain Case: 600-910
Also is controversial in it's ranking. It's high cranial diversity and occipital traits make it likely that H. eragaster is either a late transition of Homo erectus or is actually early representations of H. erectus itself. However,H. ergaster may be distinguished from H. erectus by its thinner skull-bones and lack of an obvious supraorbital foremen, and from H. heidelbergensis by its thinner bones, more protrusive face, and lower forehead. Tool use, just as the previous.
Homo erectus (1.8 MYA- 145,000)
Braincase: 900-1000
One of the best represented fossils in many regards. It can be difficult to pinpoint exactly how many due to it's many subspecies and reputation as a highly variable species. It sports unique teeth from modern humans, as well as many cranial features (such as zygomatics). It's brain case is far smaller than even our smallest range for a normal phenotype, and yet, H. erectus settlements show fire use and more sophisticated tools than it's predecessors. This animal is found nearly all over, from Africa to Europe to Asia. It is likely it proliferated into the H. neanderthalensis (we have genetic hybrid bones) Denisovans and H. floresiensis.
And of course for reference, Us!
Homo sapiens: 300,000-present
Brain case: 1200-1350 cm SQ, 4-6 ft
Homo sapiens is known to have several traits which place it in genus homo, and a few which make it unique from the others also in it. Tall, lanky posture with enormous brains (focused on the frontal lobe) and advanced tool use. Anatomically modern humans can be classified by lighter build skeletons than their predecessors. Skull is thin-walled and high-vaulted with flat, near vertical foreheads. Reduced prognathism and brow ridges as well, small mandibles and teeth comparatively. Narrow hips support the most efficient biped hominid of all time.
The trend over all can be seen as so:
Sahenanthropus, Orroren, Ardipiths
-bipedality develops
-face morphology begins to change
-bipedality becomes more efficient
Australopiths
-encephilization begins to increase at a faster rate
-face morphology changes to accommodate brain case
-Pelvis morphology changes to accommodate brain case size during birth
Homo
-Growth rates slow, and longer adolescence is seen
-Brain case allows for development of frontal lobe
-Frontal Lobe development instigates tool use
-Tool use eases life, allowing for culture
Below is a slightly more in depth look at the trends:
- Bipedalism
a) How? Reshaping of the pelvis, knee, ankle, foot and location of the foremen magnum.
b) Why? The reason for the journey out of the trees and onto the ground has been subject of dispute for decades. The current theory suggests that the East African Rift split separated a population of the Common Ancestor of Humans and Chimpanzees/Bonobos, leaving the latter in a flatter, less-forested Savanah and the former in the lush jungles. This forced the ancient hominids from the dwindling trees and onto the ground, where the grass was tall and seeing over it (to locate predators) was invaluable. We know they already could stand and walk bipedally (all great apes today can for periods of time) it became a matter of doing it often. Those who could, survived to reproduce and we see a trend of Bipedality. Additionally, this freed the hands for carrying young, bringing food back to a “home base” and later, tool use.
- Brain size
a) How? Reducing prognathism and the size of teeth and expanding the brain case.
b) Why? Intelligence increases fitness! But then, why do we not see this in other species? We do see a trend for increasing “smarts” in some, such as cetaceans or the great apes, but upping intelligence takes mutation and an environment that selects for it heavily. It is difficult to see it evolve in a lifetime.
- Culture
a) How? Increasing intelligence and social relationship dependency.
b) Why? With intelligence comes empathy and existential questions. These three factors lead to the development of new innovations for survival (smarts), Helping the downtrodden members of the group (empathy) and the advent of burial and symbolism (existential questioning).
Other factors such as
- Loss of hair: Humans are one of the most efficient animals in the world at avoiding overheating by dissipating it through sweat.
- Speech: We sacrificed the ability to eat and breath at the same time for advanced vocal cords. Human babies’ larynx match adult chimpanzees until juvenile development.
- Loss of Sexual Dimorphism: Human partition work more equally due to a more minute difference in the genders (5-11% dimorphic)
- Dental adaption: Loss of canines and increased molars came with brain size increase, and the smaller teeth came to no detriment as we began to use tools.
Part 3: We're All Damn Dirty Apes (Closing)
“Clearly, there is nothing suggesting a transition between apes and humans. All we can see from the fossil record is either apes, or humans. Saying something is a human ancestor just because its an extinct “kind” of ape, doesn’t make something a human ancestor.”
Sorry Answers in Genesis. This is abjectly false.
Human beings are bipedal, intelligent hominids that reign supreme on this Earth in regards to dominion over every other species. We are all encompassing on this planet and using our powerful brains and ability to hunt persistently we managed to rise from the grasslands of East Africa and become the formidable species the world sees today. We are not just a part of nature, we are the very essence of it. A perfect story of evolution yielding an unstoppable (not necessarily a good thing) force.
Humans are animals. But what separates us from other organisms is our intelligence and our incredible empathy. Neither are totally unique to us, but no other animal sees it in the spades we do. Humans represent a beacon of emotion and passion and artistry. We create endless symphonies, sculpt mighty megaliths and write epic tales that wind through time and generations. We learned to navigate using the stars and reached every continent, and when the sea was sated we created planes to explore the sky. The gravity of our planet couldn’t even hold us back as humans journeyed into the stars and set foot on the moon above. We craft medicines and cure diseases, suck oil from the ground to power our cars, build towers that scrape the belly of the sky. Humans care deeply for one another, and for other species as well, domesticating animals that once hunted us for the sake of companionship. We stand apart in the Animal Kingdom as creatures forged in the dust of the Savanah and gifted with the spark of curiosity. We don’t learn so that we may survive, we survive so that we may learn more about this grand, extravagant world we roam.
TL;DR Through the 17 + Hominids of the fossil record, we see morphologic trends that connect humans and our ancestors. These trends bind us to the animal kingdom and allow us to peer into our rich ancestry as we try to learn more about ourselves.
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The Transitional Species of the Mammalian Ear

7/13/2019

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​The evolution of the auditory ossicles is a story that most think begins in the synapsids (early amniotes of the late Carboniferous, sometimes referred to as the "Mammal-Like Reptiles"). We picture the classic dimetrodons lumbering about the early forests, it's anterior mandible beginning to separate and differentiate into what would become the mallus and the incus.
These synapsids already had their stapes though, the most interior of the inner ear bones. When did this happen? How? What about the nature of hearing itself?
We begin our story in the genes of our deep sea relatives. Fish have what is known as a Lateral Line along both sides to detect movement, vibration, and pressure gradients in the surrounding water. The Lateral Line is composed of neuromasts (small receptors with hair-like projections which extend into a jelly-like sac ). The Lateral Line pits are found in the fossils of ancient fish as well, dating back hundreds of millions of years ago. The Lateral Line formation is controlled by the gene known as Pax 2, and the same exact gene is responsible for the formation of the inner ear in mammals and the varying levels of auditory ability in reptiles and amphibians.
The receptors for BOTH these taxa appears in amphioxus in the form of hair-like epithelial cells and connecting neurons. Coincidentally, this organism is thought to be the precursor for all chordates.
To put it all more plainly: same gene that controls the formation of the lateral line (detecting prey, orientation, schooling) controls the formation of the mammalian inner ear (modern balance/hearing organ) and the ancestor of BOTH has the genes for the receptor type's origin.
Can we go back any further though?
Box jellyfish are incredibly "primitive" animals. They have a sort of ancient eye (unique to sea jellies), but certainly lack any type of ear or lateral line.
What do their genes say? They don't have Pax 2 (balance/hearing) OR Pax 6 (sight) but have a single gene for their primitive eyes that is a genetic mosaic of BOTH Pax 2 and Pax 6.
The implication here is that perhaps ancient cnidarians hold the key to the eventual duplication or point mutation that progenated Pax 2 and Pax 6 from the precursor mosaic.
So the genetics are in place by the time we reach the Sarcopterygians like Eusthenopteron, what about the physical form? The actual inner ear bones? Eusthenopteron's stapes is nearly in place, and by the time we meet the early amphibian Tulerpeton, the first inner ear bone is in place, although hearing would have been incredibly poor.
The synapsids though, hold the key for the mallus and the incus. Through the following organisms (some species some genera) , we find the inner ear bones separating out from the ramus of the mandible and moving interior nearer to the stapes. This is an evolutionary trend, meaning there aren't known synapsids, therapsids or cynodonts in the mammalian lineage who violate this theme of separating and migrating ossicles "primitive" to the modern "derived" malus and incus.


Stapes In Modern Position
Dimetrodon: Post mandibular bones are beginning to separate and diminish in size
Sphenocodontid: Mandibular bone migration continues to the interior of the skull, size continues to diminish
Eotitanosuchus: More bone migration and diminishing, but specifically focused on the quadrate rami (incus)
Gorganops: More bone migration and diminishing, as well as an inflated vestibule a potential primitive cochlea for primitive sound detection.
Lycaenops: In addition to the previous continued bone migration and diminishing, we see some developments in the formation of the modern tympanic membrane (eardrum): "...shows that the reflected lamina covering the angular notch is extremely thin but stabilized by low, radial crests; it seems most likely that the thin bony plate covering the recessus mandibularis already functioned as an inefficient forerunner of the tympanic membrane, although the pressure ratio must have been very low."
The author continues, addressing the idea of a partiathrinl tympanic membrane: " ‘evolutionary optimization is not measured in absolute terms, but by its relation to contemporaneous and sympatric competitors, i.e. it must have been good enough for the Permian world’ (p. 316). Luo & Crompton (1994) carefully analyzed the structural and functional transformation of the quadrate into an incus in advanced cynodonts. "
Thrinaxodon: The articular bone (malus) is in or almost in position, and is the appropriate size. And in addition, we see the development of some of the outer ear as well, the tympanic membrane now being located inside the skull. " The otic region is defined by the regions surrounding the temporal fenestrae. Most notable is evidence of a deep recess that is just anterior to the fenestra ovalis, containing evidence of smooth muscle interactions with the skull. Such smooth muscle interactions have been interpreted to be indicative of the tympanum and give the implications that this recess, in conjunction with the fenestra ovalis, outline the origin of the ear in Thrinaxodon. This is a new synapomorphy as this physiology had arisen in Thrinaxodon and had been conserved through late Cynodontia."
Furthermore, more information can be gleaned in relation to the location of the tympanic membrane, including the nature of what would become the muscles which allows mammals to move their ears about: " The remainder of this pit opens to an "un-ossified" region which comes somewhat close to the cochlear recess, giving one the assumption that inner ear articulation occurred directly within this region."
Key Information Regarding Thrinaxodon
Thrinaxodon's skull looks very much like a modern mammal, the Kangaroo Rat, in the middle of it's embryological development, only to finish up as an adult with a modern mammal inner ear. This of course supports the notion that some aspects of embryology mirror evovlutionary history (at least in utero or newborn in marsupials). Fascinatingly enough, in the link below the squamate Agama lizard, newborn and adult Kangaroo-rats and Thrinaxodon are compared.
Notice anything interesting?
Stapes and Malus In Modern Position
Cynognathus: With two ear bones in place, we are now watching the incus, which is properly diminished but still migrating. Additionally, this animal's mandibular joints are evolving as well. Generally reptiles have two jaw joints while mammals have one one. Cynognathus has two joints, like reptiles, but one of these joints is mammalian in nature!
Yanucodon: We now have one mammalian jaw joint, a nearly in place incus and an in-place malus and stapes.
Stapes, Malus and Incus in Modern Position
Eomaius/Sinodelphys: True mammals from the Early-Mid Cretaceous. Inner ear is fully functional! The former, Eomaia, is a placental mammal while the latter, Sinodelphys, is a marsupial suggesting the inner ear developed prior to the placental/marsupial split!


The picture can be painted clearly: the genetics for function and the paleontology for form are easily traced through history and present day. The two show our relationship to all other animals, from box jellies to ancient synapsids.
The study of the inner ear is, in my opinion, one of the most fascinating examples of evolution and it is all encased in the sides of our skulls by three tiny bones.
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Radiometric Dating is Corroborated by Plate Tectonics (And thus proven accurate...yet again)

7/13/2019

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YEC's will often admit that radiometric dating can be accurate for a few thousand years, but tend to insist that it fails when applied to older rocks due to presuppositions.


Dates can only be reliable if
  • radioactive decay rates haven't changed
  • the systems have remained closed
  • the rocks were't overheated
  • samples haven't been contaminated


And to them, that's a lot if "ifs". You can propose the fact that multiple dating methods agree, and they may respond that it is possible the decay rates have been slowing proportionally. You can propose coral reefs, dendochronology and ice cores, and they might wave these away as well with various statements on fast-growing reefs, double annual rings or corrupted ice samples. None of these excuses are valid, but anyone using these particular excuses won't care.
So what other methods can we use to determine the accuracy of Radiometric dating? Well, for one there is an enormous heat problem when invoking faster decay: A 70,000 C/km kind of problem actually
In conjunction with the Oklo Reactor we know the rates have remained constant.
But let's say for argument's sake that none of that is good enough either. This is when we can turn to Plate Tectonics.
When we look at a map of the Atlantic seafloor, we can make out an enormous mountain ridge, the mid-Atlantic Ridge, which divides NA and SA from Europe and Africa. Magma wells up at this ridge, which is volcanic in nature, and adds new crust thus continuing the division of these continents and the expansion of the seafloor.
Now, the ages of the rocks at the ocean crust tell a story. The closer to the ridge, the newer the igneous rock formed and thus the younger the rock. As we move outwards towards the continents on either side, the rocks get older with a maximum age of about 180 million years.
We can measure the rate of separation of the continents by using the rock ages and the distance between the landmasses as well, yielding a rate of 1.2 in per year. Changing the location (perhaps we measure at varying longitudes) we get a range of 1.2 in to 1.7 in per year.
So how does this help us test Radiometric Dating?
Satellite stations on each continent allow us to precisely measure distance movement, down to the scale of mere inches or less. Long-term measurement over the decades has given us a rate of movement around 1 inch per year, which is noticeably close to 1.2 inches per year: the rate determined by Radiometric Dating.
Let's take a moment to think on these implications. Flood Geologists claim NA and Africa separated during Noah's Flood extremely rapidly, and that the rates have slowed to their current rate by some means. For this to be the case, two entirely unrelated processes, plate movement and radioactive decay in isotopes, must have slowed down at precisely the same rate in order to give the appearance that the two corroborate one another.
Now from a science standpoint this is clear. But what about biblical? Can the literal reading of the bible justify God engaging in this kind of behavior? It would be very uncharacteristic. Romans 1:20 tells those who are religious that we can know God through Creation. If we can know Him through Creation, Creation is inherently not deceptive in nature.
What this means, is that if nature says it is 4.8 billion years old, that it is in fact 4.8 billion years old. It also means that our fossils are old as well.
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