A 2014 book
on the origin of whales (Fig. 1) by Dr. JGM ‘Hans’ Thewissen just had another burst of publicity from Discover Magazine online (see link below). Article headline: “How ancient deer lost their legs and became whales”
Dr. Thewissen is a professor
at Northeast Ohio Medical University.
According to the Discover article by Joshua Rapp Learn:
“Cetaceans include everything from dolphins to whales.”
in the large reptile tree (LRT, 1818+ taxa; subsets Figs. 5, 6) Cetacea is no longer a clade. That’s because traditional ‘whales’ are diphyletic with separate ancestries still not recognized by whale experts like Dr. Thewissen. Odontocetes (toothed whales, Figs. 2, 6) arise from tenrecs (which also echolocate). Mysticetes (baleen whales, Figs. 3–5) arise from mesonychids, hippos, anthracobunids and desmostylians.
According to the Discover article:
“Indohyus belonged to the even-toed group of ungulates, which today includes giraffes, horses, pigs and cetaceans. Indohyus basically looked like a tiny little deer, a deer the size of a cat,” says Hans Thewissen, a professor at Northeast Ohio Medical University who has studied whale evolution for years and wrote the book The Walking Whales: From Land to Water in Eight Million Years. Today, a distant deer-like relative called the water chevrotain (or African mouse-deer) can be found from central to southern Africa. These deer eat flowers and fruits and live near rivers, which they use as escape routes to flee land-based predators or even eagles.
Ungulates have no relationship to whales in the LRT.
Think of it. Four, two or one-toed hooves to flippers? That’s untenable, but evidently that’s what taxon exclusion gives you. Simply adding taxa in the LRT (Figs. 2–4) shows that Thewissen’s study suffered from taxon exclusion prior to Pakicetus (Fig. 2), the most basal taxon common to both studies.
According to the Discover article:
“Thewissen’s research examining stable isotopes in Indohyus fossils shows they ate land plants, but their dense bones suggest they spent a lot of time in the water. The hippopotamus — the closest living relative of whales that live outside the ocean — also has dense bones, which help weigh it down while walking along the bottom of lakes or rivers. The evolutionary descendant of Indohyus, called Pakicetus, began to adopt a more aquatic lifestyle as they abandoned a vegetarian diet, based on the way their teeth look, Thewissen says.”
So this explains why Thewissen did not answer my emails.
Two years earlier he had authored a book (Fig. 1) that promoted the myth of a single origin of all whales originating from hoofed ungulates. The news I sent him, that whales were not a single clade, was probably upsetting, considering the time, treasure and reputation Thewissen put into his career and his publications. You can’t fix print once it is printed.
It should be up to professionals and PhDs
to build matrices and run analyses of fossil taxa. That’s what they are getting paid to do. They are the ones who know how to run the analyses. They are the ones who have access to fossils. They have professional colleagues, post-docs, PhD candidates, undergrads, volunteers and grants. Since the pros and PhDs have chosen to exclude so many pertinent taxa, amateurs are taking up the slack, hoping to contribute to this ancient science we call paleontology.
Taxon exclusion remains the number one problem
vexing paleontology and paleontologists. Adding taxa to minimize taxon exclusion is what the LRT is all about. It resolves problems like the origin of whales with taxa that document in detail the gradual accumulation of traits (Figs. 3, 4) we expect from microevolution over deep time, now back to Ediacaran nematodes.
Since this is science,
anyone can repeat this experiment simply by following the materials and methods. You don’t have to be a scientist. You don’t have to be an expert. That will come with time and study, the same way it comes with time and study for those who pay dearly for their education. Don’t trust me. Don’t trust others, even paid professionals with PhDs. Build your own matrix and run the analyses yourself to find out for yourself that deer, or any other ungulate, did not give rise to whales.
Thewissen JGM et al. (4 co-authors) 2007. Whales originated from aquatic artiodactyls in the Eocene epoch of India. Nature 450:1190–1194.
Nature Comment: “Adding taxa documents the origin of odontocetes from anagalids, leptictids and tenrecs (which echolocate) leading to Indohyus and Pakicetus apart from the origin of mysticetes from mesonychids, hippos, anthracobunids and desmostylians with Desmostylus closer to right whales and Behemotops closer to rorquals. Cladogram here: http://reptileevolution.com/reptile-tree.htm and manuscript here: https://www.researchgate.net/publication/328388746_The_triple_origin_of_whales”
Thewissen JGM 2019, 2014. The walking whales. From land to water in eight million years. University of California Press. 256pp.
ResearchGate.net manuscript on the triple origin of whales
article by Joshua Rapp Learn in Discover Magazine online: how-ancient-deer-lost-their-legs-and-became-whales