Answering Bechly's challenge

Günter Bechly has a new article on Evolution News that ends in a challenge of sorts. Apparently, Bechly is of the opinion that, should a pair of species diverge and go off on their evolving ways, one would expect to see (inevitably, invariably?) dramatic differences in such species pairs as time passes. Bechly presents different a number of different species pairs that have been happily evolving for millions of years or more, but still bear striking morphological resemblances to each other. Apparently, this is a problem for evolution.

Participants here can explore this proposition, that I will confess makes no sense to me. What I would like to focus on in this post is the following assertions and challenge (I have added some emphasis to highlight the assertion I am addressing):

Two Indisputable Facts

These examples could be expanded endlessly but should be sufficient to establish the point. There are clearly limits to what unguided evolution can do within a few million years, and these limits are far below the level of any major body plan transitions. Thus, we can safely conclude that there are two indisputable facts that require an adequate explanation:

1.) There are many examples of fossil species pairs with very different body plans that diverged within a window of time of 5 (±5) million years. This is even more remarkable if we consider that there are only about 350,000 described fossil species (extrapolated based on data in Teichert 1956, Valentine 1970, Raup 1976, and Alroy 2002), which represent only a tiny fraction of the estimated 5-50 billion species that have ever lived on Earth (Raup 1991).

2.) There exist no living species pairs with even remotely similar differences in body plan that are dated to have diverged in a similar time frame. This is even more remarkable if we consider that there are an estimated 8.7 million living species (Mora et al. 2011, Strain 2011, Sweetlove 2011), of which more than 2 million are described (IISE 2012). Previous estimates of the total number of living species varied from 3-100 million species (May 1988, Tangley 1997, Chapman 2009), but if microbes are included, it could even be up to a trillion living species (Locey & Lennon 2016, Latty & Lee 2019).

Considering the fact that windows of time of only 5-10 million years account for most of the abrupt appearances of new body plans in the fossil record (Bechly & Meyer 2017, Bechly 2021), the Bayesian likelihood of not finding a single example of similar morphological disparity having originated on a similar time frame among the millions of living species is basically close to zero. I consider this simple argument as a final nail in the coffin of Darwinian unguided evolution.

A Public Challenge

Having made my case, I here formally and publicly pose the challenge again to prove me wrong. My dear Darwinist friends and colleagues, please find in the vast database of 97,000 species at TimeTree.org just a single example of any pair of different species that have diverged about 5 million years ago (give or take a few million years) according to a consensus of multiple molecular clock studies, and that exhibit a morphological disparity in their body plans comparable to, say, Pakicetus and Basilosaurus .

No Conceivable Reason

There is no conceivable reason why a disparity like that between Pakicetus and Basilosaurus should be limited to the fossil record, where it can be found in numerous examples among all groups of organisms, while being totally absent among the millions of recent species. So, let’s be generous and not restrict the challenge to the TimeTree database. Just find any pair of species among the millions of living species to meet the challenge. Only one!

A long, long time ago, on another Ev/Cre discussion board, I discussed one collection of examples that meet this challenge. The board itself (the ARN discussions) is long since defunct, but Nick Matzke captured the post for posterity here. To sum up my response: The Hawaiian Silversword Alliance is a collection of plant species native to Hawaii that undeniably shares a common ancestry and have evolved into a myriad of different plant body plans, the range of which I would argue far exceeds anything that is seen in mammals. In my opinion, this is exactly the sort of example Bechly is asking for (and that I suspect he believes cannot exist).

I am not sure how this affects his argument, since the argument itself doesn’t make much sense. But regardless, the Silverswords are, to a tee, a " pair of different species that have diverged about 5 million years ago (give or take a few million years) according to a consensus of multiple molecular clock studies, and that exhibit a morphological disparity in their body plans comparable to, say, Pakicetus and Basilosaurus ."

I won’t bother trying to upload photos - instead, visit the web site for some dramatic examples.

(Aside for @pnelson, if you still check us out from time to time - here is an excellent opportunity for interlocution. I invite you to avail yourself of this opportunity to explore some fascinating biology. Better still, assuming that you communicate with Bechly, pass along my personal invitation for him to visit us here and explain things a bit more.)

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