GURPS: Ecosystems and Evolution

[Bruno]

Originally Posted by Vaevictis Asmadi

lwcamp is right about the brain being a hungry organ. The theory about human evolution is that our ancestors couldn't have larger brains until they started eating significant amounts of meat. Meat has denser energy than plants and is also easier to digest, allowing us to have smaller guts and shorter intestines.

There's also the recent evidence of an island-bound goat, now extinct, that adapted to a poor and restricted environment by reducing metabolic rate more and more and more... and one of the primary casualties was its brain, which was reduced to reptilian proportions. They're guessing it actually became virtually ectothermic by the end, before IIRC human sailors showed up and ate it.


EDIT: Good source:
http://www.physorg.com/news177755291.html

Humans settled and ate it. Also they reduced eye size significantly, another complicated organ.