MSNBC's Birthday Present to Charles Darwin: Puff-Pieces on Evolution (Part 4) - Evolution News & Views

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MSNBC's Birthday Present to Charles Darwin: Puff-Pieces on Evolution (Part 4)

In Part 3 of this series, I discussed a recent article published on MSNBC titled, "Fossils reveal truth about Darwin's theory" that puffs the fossil evidence for evolution. In that installment, I discussed the fact that the article relied entirely upon evolutionary scientist Donald Prothero touting various examples of alleged transitional forms -- but that Prothero's arguments didn't disclose the real history of the fossil record, and included much speculation and assumption-laden evolutionary interpretation.

One of the showcase fossils in the article is the alleged "frogamander," which is supposedly a transitional form between frogs and salamanders. Frogs and salamanders are of course both amphibians, and indeed the article admits that the fossil is simply "a toothed amphibian" (nothing extraordinary), and asserts this fossil is special because it purportedly has "a wide skull and large ear drum (like frogs) and two fused ankle bones as seen in salamanders." A brief analysis of this alleged transitional fossil shows its underwhelming features.

The Nature paper that first reported the fossil opens with a striking retroactive confession of evolutionist ignorance, as it states: "The origin of extant amphibians (Lissamphibia: frogs, salamanders and caecilians) is one of the most controversial questions in vertebrate evolution, owing to large morphological and temporal gaps in the fossil record." So does this one fossil solve all these questions? Of course not. And of course the fact that this field is one where transitional links are strikingly missing is not discussed by Prothero in the MSNBC article.

The Nature paper further explains that "strikingly, the broad skull shape, the greatly enlarged vacuities on the palate, and the shortened vertebral column and tail give the immediate impression of a Palaeozoic batrachian." Batrachians include frogs, toads, and other tail-less amphibians, so in other words, the body of this fragmented fossil is largely like a frog or toad. This fossil appears extremely froglike, apart from its allegedly "fused ankle bones." Behold, below are the incredible purported "frogamander's" transitional fused ankle bones, each about 1-millimeter in size (labeled bc and dt3):


(Adapted by permission from Macmillan Publishers Ltd: Anderson et al., "A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders," Nature Vol. 453:515-518 (May 22, 2008), Fig. 3b)

Are you convinced by these two amazing <1 mm sized bones that this is a transitional form worthy of touting in Foxnews or MSNBC headlines? You shouldn't be, because a lot of assumptions went into the claim that it had salamander-like ankle-bones. The original Nature paper shows that the limbs of this fossil were highly fragmented and largely missing, as seen in the diagram below:


(Adapted by permission from Macmillan Publishers Ltd: Anderson et al., "A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders," Nature Vol. 453:515-518 (May 22, 2008), Fig. 1b)

Their argument that this fossil has salamander-like ankle-bones rests on 2 assumptions: (1) That the millimeter-sized bones were found in their real-life location, and (2) That the ankle bones that aren't there, aren't there because they hadn't hardened yet, not because were lost from the fossil. While many limb bones (including many tarsal and carpal bones) are missing from this fossil, the authors assume that the missing ankle-bones bones weren't lost from the fossil (like many other bones clearly were), but that they hadn't ossified yet, and thus this fossil allegedly exhibits a salamander-like developmental pattern. But if the other ankle-bones bones are just plain missing -- like many other bones in this fossil are obviously missing -- then their case for salamander-like ankle-bones is greatly weakened. Given that we know that a lot of tarsal (ankle) bones are missing from this fossil, it's entirely possible that the bones normally found in a frog foot are just plain missing. Evolutionary assumptions -- not the raw data -- are what is driving this interpretation.

Even if they're right about the fossil reconstruction, we're still talking about an evolutionary story based upon two millimeter-sized ankle bones -- not exactly a shining example of transitional features. And even if this is an ancestor of frogs and salamanders, their story isn't neat and tidy. It requires some pesky evolutionary reversals, as the Nature piece states: "If our interpretations are correct, the preaxial pattern of digital development is either independently derived in Gerobatrachus and salamanders, or primitive in batrachians but reversed in frogs." Indeed, their phylogenetic tree for various living and extinct amphibians has a consistency index of only 0.250, meaning that ~75% of the character data conflict with the phylogenetic hierarchy in their tree (i.e. HOMOPLASY). To say the least, this does not inspire confidence in the integrity of their claimed evolutionary relationships.

Of course none of this is mentioned in the MSNBC puff-piece on evolution, which simply calls this fossil the amazing "frogamander" that demonstrates the "truth about Darwin's theory."

I think that Niles Eldredge would beg to differ, as he would say that the truth about Darwin's theory is also revealed in the largescale pattern we see in the fossil record where evolutionary change is not documented by fossils. As I quoted in Part 3, the words of evolutionary paleontologist Niles Eldredge are again appropriate: "...we have proffered a collective tacit acceptance of the story of gradual adaptive change, a story that strengthened and became even more entrenched as the synthesis took hold. We paleontologists have said that the history of life supports that interpretation, all the while really knowing that it does not."

Eldredge's criticism of his own field seems to be ripe for application against Donald Prothero, the geologist that MSNBC uses as its singular authority on evolution and the fossil record. This MSNBC puff-piece on transitional fossils provides an illustrative case study in the conflicting views surrounding these allegedly transitional fossils. And when they rely on polemical authors like Donald Prothero who misrepresent views on the nature of some of these fossils, you can be sure that the goal is to pay homage to Darwin, not careful or objective scientific analysis.