Cladist fundamentalism takes on new meaning

51OftfuYlSL._SY344_BO1,204,203,200_One of the strangest things I’ve read in a while in The Monkey’s Voyage:

What Nelson and Platnick were saying was that, if the evolutionary and tectonic patterns matched, one could infer that the human lineage-meaning people as people, not as porto-humans or tree-living apes or any more distant ancestor-extended back to 66 million years and more to the Mesozoic, which was…the Age of Dinosaurs. Never mind that the intensively studied human fossil record indicates that the genius Homo is only a few million years old. Never mind that the genes of humans and chimps are so similar that they suggest that the common ancestor of these two lineages…existed only 7 million years or so ago. Never mind a whole host of fossils showing that a success of progressively deeper human ancestors-the first hominids, the first apes, the first monkeys-were not around in the Mesozoic. All that evidence is worthless. Molecular clocks don’t work. The fossil record is hopelessly incomplete. People might have lived with dinosaurs.

The author is referring to a portion of Systematics and Biogeography (free PDF at link), a text which was at the forefront of the cladistic revolution which was in full swing in the 1970s. Cladistics was an important development, in that the discipline introduced rigor in systematics and a more formal scaffold onto evolutionary phylogenetic methods. But many evolutionary biologists believe that the movement has lost its way and become ossified into a dogmatic philosophy at best, and a cult at worst.

Dinotopia_LAFT_coverSo as to not fall into the trap of woolly and ad hoc thinking which was common in evolutionary biological methods of systematics and taxonomy in the first half of the 20th century, the cladistic school tends to hew very strongly to a set of methods, and follow their implications to their logical, if weird, conclusions. Here you see it on display. Human phylogeographic variation does reflect continental scale structuring, and continents have emerged on the order of tens of millions of years. Ergo, a hypothesis that is being entertained above is that human differentiation is due to vicariance, where a panmictic population is separated by geographic barriers. So the authors are seriously suggesting that humans have developed tens of millions of years ago, and modern differences emerged due to the separation enforced by Plate Tectonics! (the author of The Monkey’s Voyage emailed one of the author’s of the text to make sure that this section wasn’t a weird tongue-in-cheek thought experiment, and it seems it wasn’t)

Often science gives strange results. We mustn’t shy away from that. But we also need to be wary of the crazy. The punctilious to a fault adherence of cladists to a very precise and delimited set of methods can be commended on some level, and it was certainly useful in past decades. But more recently they’ve withdrawn into a weird intellectual ghetto as the world has moved on.

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