When did humans start cooking and what did they cook ...

Did Cooked Tubers Spur the Evolution of Big Brains? Article from 1999 reports that Harvard anthropologist Richard Wrangham (and colleagues) suggest "cooking--in particular, cooking tubers--sparked a crucial turning point in human evolution."

Now, in 2007, this article (Did Primordial Chefs Feed Our Giant Brains?) reports that cooked meat --what happened to the tubers?-- is what Wrangham is proposing may have effected that "quick and dramatic evolutionary impact" on our brains.

Richard Wrangham (along with Dale Peterson) is also one of the authors Demonic Males: Apes and the Origins of Human Violence (Washington Post review, National Review Book Review).