Methinks it is like a sauropsid


Eugene McCarthy, the author of that crackpot stabilization theory, has discovered my review and is now making a noise on twitter. He’s gone from thanking me profusely for mentioning him, to whining that I stole his figures, to complaining that I don’t understand his theory at all, all in the last 24 hours.

But here’s the fun part. Recall that one of his bizarre claims is that whales did not evolve from terrestrial artiodactyls, but from mosasaurs, mesozoic marine reptiles, instead. But the anatomy shows that mosasaurs are derived squamates, reptiles, with a completely different skeletal organization than a mammal. This has attracted the attention of Darren Naish and Tom Holtz, fully qualified comparative anatomists and paleontologists, who actually know a great deal about the structure of these animals, and are giving him a spectacular ass-whooping. Browse it on Twitter.

The basis of his claim is that mosasaur teeth “look like” sperm whale teeth. That’s not a good criterion, and it’s not true; as has been pointed out to him, basal mosasaurs are pleurodont (that is, the teeth are fused to the inner side of the jaw bone), not socketed as are sperm whale teeth. He’s also now claiming that mosasaurs swam by vertical motions of their tails, like whales…but he’s citing articles with poor comprehension. The cited articles show evidence that mosasaurs propelled themselves with axial motions of the tail, which is a far more general statement; they moved by sweeping their tails like oars, but it says nothing about vertical vs. horizontal undulations.

So I went back to McCarthy’s book to see how he backed up this ridiculous claim. He doesn’t. He cites Pieter Camper, an 18th century anatomist, as proposing the idea that whales are related to mosasaurs. His critics are citing contemporary and detailed papers. This, however, is really the totality of McCarthy’s argument:

The varanid theory was based on Adriaan Gilles’ assertion that certain skeletal characters found in mosasaurs are not found in modern whales. However, a glance at figures 9.4 and 9.5, will convince most readers that mosasaurs have much in common with early whales. Certainly, they have far more in common with whales than does the late Cretaceous terrestrial insectivore traditional theory posits as the common ancestor of whales and all other placental mammals (it should be emphasized that all of the various forms classified as mosasaurs, too, are of late Cretaceous age). They are also far more similar to whales than is Pakicetus. One would not expect the ancient ancestors of whales to have every characteristic of modern whales. Their dissimilarity with respect to a few minor bony traits should not be allowed to obscure the well established fact that mosasaurs were huge, whalelike, air-breathing animals with whalelike teeth and that they had the same sort of prey as modern whales.

The referenced figures are grainy, low resolution images that do not do an adequate job of displaying the structures. The “dissimilarity with respect to a few minor bony traits” is trivialized; these are actually substantial differences in the arrangement and number of bones in the skull, where the mosasaur displays a fairly standard reptilian pattern and the whales show a mammalian pattern. They only look alike if you don’t look at all closely. How can you say that the jaw joint or the auditory complex of a whale look anything like that of a reptile? Only by not looking.

His other argument is that it would take fewer evolutionary changes to transform a mosasaur into a whale, than a shrew into a whale. This is nonsense. Turning a reptile into a mammal requires a major reorganization of the bones of the skull, and further, requires that those shifts exactly mimic the pattern found in other mammals. There is no reasonable way to accomplish that. Again, the basis of his entire argument is a complete ignorance about the anatomy!


This is the well-supported pattern of whale evolution. Notice: no mosasaurs.

whale_evo

Comments

  1. F [nucular nyandrothol] says

    For a half second I was hoping there to hear about a crackpot stabilization theory, but I rapidly recognized that you were talking about that crackpot stabilization theory.

    I’m now also looking for headasplody stabilization, so if anyone has a theory or method for this, I’ll listen.

  2. Mario says

    Have I just read in the tweeter exchange that he denies the existence of scales? Yes, it seem I have. I’m going to have a lay down.

  3. noastronomer says

    One thing that bothered me about McCarthy’s theory from your original post:

    Even if whales did evolve from mosasaurs, where did mosasaurs come from?

    Mike.

  4. says

    basal mosasaurs are pleurodont…not socketed as are sperm whale teeth.

    In all seriousness, fuck I love science. It’s like this wonderfully mystic, but fully accessible and understandable, way of thinking.

  5. Ogvorbis says

    Even if whales did evolve from mosasaurs, where did mosasaurs come from?

    Obviously, they were a crossbreed of a proto-lobster (trilobite?) and a lizard. Explains the up-down and left-right problems with the tail motion, right?

  6. Crip Dyke, MQ, Right Reverend Feminist FuckToy of Death & Her Handmaiden says

    Oooh! Ooh!

    I have a theory.

    Mosasaurs and whales are both narrower at the very front, get big in the middle, and get narrower again at the tail. See? Common descent!

    — Anne Elk

    PS. Darn it! Now I’ve connected my true identity with my online pseudonym.

  7. Ogvorbis says

    Mosasaurs and whales are both narrower at the very front, get big in the middle, and get narrower again at the tail.

    So does a perfecto cigar.

  8. says

    Mosasaurs and whales are both narrower at the very front, get big in the middle, and get narrower again at the tail.

    So does a perfecto cigar.

    But sometimes a cigar is just a cigar.

  9. Epinephrine says

    Is the split between the Mysticetes and the Odontocetes really so early? I thought that the baleen whales were newer, appearing maybe 25 mya.

  10. indicus says

    Does anyone else remember Kent Hovind explaining how chameleons are really just Ceratopsian dinosaurs which shrunk after the Fall of Man, blah, blah, no more warm climate due to earth’s ice atmosphere, blah, blah? Sounds exactly like it, no? Can someone send in the nice guys with the white blazers that button up in the back?

  11. mudpuddles says

    Hello PZ, can you give a reference / source for that pictorial of whale evolution? I’d like to use it.

    Thanks!

  12. indicus says

    “Don’t use mental illness as an insult. It’s assholy.”

    First of all, its a common refrain just like calling a person you consider an idiot a ‘retard’. Second, its in the same vein as calling these people batshit crazy… doesn’t mean they are literally crazy, just plain ‘ol batshit.

  13. Rumtopf says

    No, indicus, those slurs are ableist too and none of that shit is welcome here, which is incidentally what makes Pharyngula one of my favourite places. Read the rules, specifically the “No splash damage” part.

  14. neutrinosarecool says

    What you have here on the part of diehard creationists (or racist/sexist atheists) isn’t developmental-neurological retardation – but it could be a form of mental illness known as the idee fixe.

    Merriam-Webster Medical Dictionary: “a usually delusional idea that dominates the whole mental life during a prolonged period (as in certain mental disorders) – called also fixed idea.”

    One characteristic of this condition is a refusal to adjust one’s viewpoint / beliefs / etc. when faced with contradictory evidence – which is what any good scientist must do. In contrast, religious thinking is fundamentally opposed to reconsidering cherished beliefs in the face of contrary evidence (and this pattern is also seen among diehard racists, sexists, etc. – which is why it is called prejudice, as in pre-judging a question before seeing any evidence).

    Take whales – for example, you don’t need to rely on morphological characteristics alone, you can also look at DNA evidence, for example see this highly cited 1993 Nature paper:

    “Revised phylogeny of whales suggested by mitochondrial ribosomal DNA sequences”

    Complete version:

    http://www.evolutionsbiologie.uni-konstanz.de/pdf1-182/P020.pdf

    How anyone can read that and still hold on to some bizarre notion of whales evolving from marine reptiles is a mystery.

  15. ChasCPeterson says

    can you give a reference / source for that pictorial of whale evolution?

    The art is by Carl Buell, and it’s from Carl Zimmer’s evolution textbook, The Tangled Bank.

  16. says

    Image is Figure 1.1 from Carl Zimmer’s The Tangled Bank.

    If you want a more detailed review of the (nearly current) status of whale origin studies (behind a paywall, unfortunately), there is Uhen, M.D. 2010. The Origin(s) of Whales. Annual Review of Earth and Planetary Sciences 38:189-219. doi: 10.1146/annurev-earth-040809-152453

  17. says

    Oldest known mysticetes are later Early Oligocene (and aren’t even “baleen” whales yet), but since crown-group odontocetes are their sister taxon and go back earlier, we can infer presence of mysticetes at the Eocene/Oligocene boundary (~34 Ma). These are the fossil dates; the figure in the book might use molecular divergence dates.

  18. Amphiox says

    I always thought Basilosaurus looked kind of like a generic mosasaur, in a general sort of way. But I always knew that was an example (and a weak one) of convergent evolution.

  19. Ogvorbis says

    And I remember, when I was younger, wondering if, in addition to Basilosaurus, there was also a Garlicasaurus, Oreganasaurus, or, perhaps, a Pestosaurus.

    Which almost makes more sense than this crackpot stabilization theory (use either of F [nucular nyandrothol]’s versions).

  20. Ogvorbis says

    Looking at the graphic, I am struck by how superficially similar the skulls of Pakicetus and Rhodocetus are to some of the less derived ceratopsians. Completely different diets, completely different lineage, completely different environment, but oddly, though very superficially, similar.

  21. Lofty says

    Another case of a rough resemblance being reclassified as exactly the same by someone without modern scientific tools.

  22. Amphiox says

    And just look at those skulls. See how one of the most prominent features in many of them is the giant single synapsid hole?

    Mosasaurs, naturally, are diapsids.

  23. David Marjanović says

    What, that macroevolution guy is Eugene McCarthy?

    Is the split between the Mysticetes and the Odontocetes really so early? I thought that the baleen whales were newer, appearing maybe 25 mya.

    On the mysticete side, Llanocetus dates from the Eocene-Oligocene boundary.

    If you want a more detailed review of the (nearly current) status of whale origin studies (behind a paywall, unfortunately)

    No, it’s not behind a paywall! I just downloaded it at home!

    I am struck by how superficially similar the skulls of Pakicetus and Rhodocetus are to some of the less derived ceratopsians.

    Heh. In dorsal view, yes – but those holes are the temporal fenestrae, filled with jaw muscles, while ceratopsians have that frill (which usually contains holes) behind the rest of the head.

    Mosasaurs, naturally, are diapsids.

    To be scrupulously fair, though, the lower temporal fenestra is open at the bottom.

  24. Ogvorbis says

    but those holes are the temporal fenestrae,

    Wait. Those are the temporal fenestrae? Damn.

    [looks more closely at image]

    Damn. That’s cool.

    (off topic: I am currently reading Clack’s book about the evolution of tetrapods and am really enjoying it)

  25. johnharshman says

    No, it’s not behind a paywall! I just downloaded it at home!

    Perhaps you have a home Annual Review subscription you don’t know about, because I went straight to the paywall.

    Oldest known mysticetes are later Early Oligocene (and aren’t even “baleen” whales yet), but since crown-group odontocetes are their sister taxon and go back earlier, we can infer presence of mysticetes at the Eocene/Oligocene boundary (~34 Ma).

    Hey, just because crown group odontocetes exist, we can’t infer that crown group mysticetes exist; only total group mysticetes. To infer crown group mysticetes you need an actual crown group mysticete. Does Mysticeti have a branch-based definition?

  26. Owlmirror says

    I just want to re-post the link @#23 (thanks Antiochus).

    A phylogenetic blueprint for a modern whale

    Because even though the paper is not open-access, the figures are available — and they are by the same Carl Buell who did the illustrations for the figure in the OP, and is a generally excellent illustrator of science and biology.

  27. anchor says

    “…a glance at figures 9.4 and 9.5, will convince most readers that mosasaurs have much in common with early whales.”

    Heh. Yes, a glance is just what it takes to get it so wrong.

    McCarthy whole thesis seems based on copious glancing and citing antiquated sources for smidgeons that support his glances.

  28. Azkyroth Drinked the Grammar Too :) says

    Um, insofar as this guy posits that distantly related organisms regularly hybridize, given the extent of bestiality over the years, why aren’t zoomans a thing?

  29. mrheteronormative says

    Oh my gosh! This is a post about.. Science?!

    PZ. I think you’re making a mistake here. This blog is about feminist agitation and republican hate. We don’t want no stinkin’ science here!

  30. says

    McCarthy showed up back in June 2012 on Wikipedia speaking highly of his self-published book in the third person under a pseudonym, testing to see how regular editors there at the Tree of Life project would respond to his ideas. Just more attention seeking behavior, I believe. He’s also quite the bully when not getting his way as he quickly turned abusive but then mellowed after being revealed to be McCarthy.

  31. meursalt says

    You should have left the whale issue alone, PZ. Now we know you’re full of it. All it takes is one look at the name “Basilosaurus” to tell me whales are descended from reptiles.

    Skeletal differences are trivial. What really matters is streamlining, and swimming, and stuff. Those features would be almost impossible to duplicate without common descent through hybridization. Also, it’s totally no big deal for reptiles to independently evolve mammary glands and placentas and all that icky girly stuff.

    QED. Case closed. Checkmate, atheists!

    [crossing my fingers since “preview” is broken for me in the new layout.]

  32. David Marjanović says

    Perhaps you have a home Annual Review subscription you don’t know about, because I went straight to the paywall.

    Stupid me. I was using the link in comment 34, posted by Tom Holtz on Twitter.

    A phylogenetic blueprint for a modern whale

    Now that’s an impressive paper.

  33. texasaggie says

    Save that graphic so that the next time some dork claims that there are no transitional fossils, you can show it to him/her.

  34. leonpeyre says

    [Mosasaurs] have far more in common with whales than does the late Cretaceous terrestrial insectivore traditional theory posits as the common ancestor of whales

    So? Dolphins have far more in common with sharks than they do with, say, goats, at least if you look at certain traits rather than others–but that’s no indication that dolphins are fish rather than mammals.