Thread by @HermanPontzer

Still wrong, even in less “humorous” form. This sort of poor evolutionary thinking is a big problem esp as medicine adopts a more evolutionary perspective (which is great when done well).

Hold my beer I’m writing a thread! 1/

https://twitter.com/ProfTimNoakes/status/1162283816842477571

Argument is: Species X needed to evolve trait Y, and so adopted behavior Z. Folks, doesn’t work that way.

First, for any “crucial” trait, there are 10000s of species that lack it. Theres always many solutions. Thinking the trait was inevitable / necessary is wrong. 2/

In the specific case of hominins it’s clearly false that Australopithecus (ancestral genus to Homo) *needed* to get bigger. They lasted 3+ million years, longer than Homo has. And lots of other species (like baboons) thrive on savannah at small body size 3/

Second, it’s clearly not true that species need to eat meat to get bigger. Plant eaters tend to be larger than meat eaters. (Jarman Bell principle). 4/

In primates specifically, the species that depend on animal protein tend to be the smallest, and the largest are dedicated vegetarians. See for example tarsiers vs gorillas 5/

Also, the only other ape that eats an appreciable amount of meat - chimps - are not larger or brainier than other non-human apes 6/

In our own hominin lineage 1) meat eating precedes larger body size, 2) larger body size precedes larger brains, and 3) there are meat eating spp of Homo that remain - or re-evolve - small brains and bodies. H naledi, H floresiensis prob others. 7/

Sloppy uninformed evolutionary arguments are unhelpful & pollute the application of evolutionary thinking to health / medicine etc. Even when it’s meant to be “humourous”. Evolution is deceptively subtle & deserves careful thought & study 8/

If you’ve made it this far, think about donating to @NCSE to promote strong education in evolution. It might be too late for some but I haven’t given up hope! 🙂