Bechly's "Species Pairs" Challenge

Gunter Bechly claims that:

  1. There are “many” examples in the fossil record of species with very different body plans (where “very different” means something like “readily categorized by laypersons as different kinds of creatures”) that diverged from each other in roughly 5-10 Ma (for an unspecified value of “many”, unfortunately, and he only gives one real example here)
  2. There are no two modern species with very different body plans which diverged from each other in less than 10 Ma (or so).

And he considers this a problem with evolutionary theory (implication is that if we see “many” rapid changes in the fossil record, we should see some rapid changes having happened in the recent past). Experts, what are your thoughts on this? I suspect that one or both claims are a bit exaggerated at the very least, but there is probably more to be said in response to this.

Edit: @Art posted a response to the challenge around the same time I made this thread (or at least, our posts received moderator approval at the same time). See his thread here: Answering Bechly's challenge

[MOD NOTE: The other thread has been merged with this one.]


Sea otters and ferrets.

They’re readily classified as different kinds of creatures by laypeople, not least because one is aquatic and the other isn’t, and they diverged just over 10mya.

Oh, and I also think claim 1 is exaggerated. I’ve checked the reference given for his claim of “the origin of trilobites from worm-like ancestors in less than 13 million years”. Not only does it not mention worm-like anything, but it actually says

The first arthropod traces ( Rusophycus ) appear at approximately 537 Ma, shortly after the start of the Cambrian at approximately 540 Ma. Crown group euarthropods (trilobites) appear at 521 Ma…

That’s 16my between trilobites and Rusophycus, trace fossils which are definitely not worm-like because they show signs of being made by legs.

Bechly, like most ID and YEC advocates, must be counting on no-one checking his references.


Brilliant minds think alike. It would seem as if our posts were released from the moderation queue at the same time.


No one seems to have noticed that Bechly includes this among the examples of species pairs undergoing the change he denies could happen thru evolutionary processes:

… … the origin of our own genus Homo and of a globular braincase correlated with the “Creative Explosion” of symbolic thinking within Homo sapiens .

So it seems he has answered his own challenge: Humans and chimps are one example.


I did notice that, though he gives a flimsy reason for excluding that as a valid response (oh, that just demonstrates human exceptionalism!). Honestly I would not be surprised if every example he was offered was met with a similar response. (Otters and ferrets: not different enough! Silverswords: plants don’t count!)


I would prefer to leave both open for now. I have invited Bechly to join us, and used the URL to the other topic as a guide. If things get merged, that may mess things up.

1 Like

Has he suggested a way to choose an impartial panel to judge whether any suggested example really has basically different body plans? He hasn’t? What a surprise!

I’d be surprised if he didn’t.

OK. If Bechly responds, should we offer him visiting scholar status? He might be more willing to participate in a closely moderated discussion. I’m thinking just the two of you, and maybe one or two others you designate.

it’s annoying how rarely ID proponents will engage in an open and free exchange of ideas with people they claim to consider their peers, and instead routinely insist on being utter drama queens about the whole thing. But so it goes. It would be very interesting to see Bechly defend his position against knowledgeable interlocutors. Do we have someone who knows paleontology well in this forum?


Bechly has declined the invite. So I guess a merge of the two threads would be OK. @structureoftruth ?

I am shocked. Shocked.


Yep, I have no problem with the mods merging the threads. Thanks!


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 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.)


From the Bechly article

Here, I want to introduce another new argument and formulate a challenge to my Darwinist colleagues.

This line of argument looks to me just like a reframing of the evolution by jerks vs evolution by creeps discussion, which far from new, has been contended for decades. Bechly seems to maintain that if the only people in your life are creeps, there can be no jerks in the world.

This is a great example in that it also demonstrates an impetus for marked change in morphology: The Hawaiian chain is younger than Bechly’s time frame, and so presented a environmental niche which had not been already fully explored. I am no expert on punctuated evolution, but it seems evident to me that evolutionary novelty is most vigorous given unexploited opportunity, due to environmental shifts such as an asteroid impact devastating the existing biosphere, or a hinge mutations such as antifreeze in fish allowing further downstream distinctive adaptations to arctic conditions.


I’m partly kicking myself, because I recently heard of the Hawaiian Silversword Alliance! But I didn’t think of them when I came across Bechly’s challenge. A Youtube channel called AtlasPro did a video called The Amazing BIOGEOGRAPHY of Hawaii - YouTube and he talks about them a little bit. The section on the silverswords starts about 40 mins 30 seconds in, but the whole video is well worth a watch.

I invoke the diversity of breeds of domestic dogs. Seems to me that the degree of difference among breeds of domestic dogs are pretty large considering their ancestry within the last 15-20k years:

Cauliflower also seems kinda deviant if you ask me, so do some of those peppers:


No conceivable reason huh? No one can conceive of a reason, even in principle, why certain evolutionary transitions only happened when they did and don’t happen all the time all over the place? That’s like saying there’s no conceivable reason why World War II didn’t happen in 2241 BCE. It’s ridiculous on it’s face, and anyone can conceive of reasons why.


So to summarize: Bechly issues his challenge yesterday.

It is answered and debunked today.

Any guesses on for how many more years we will be hearing from the ID Creationists that this challenge has never been answered?


Topics merged, and hopefully not too muddled.

1 Like