"Meat-Based Diet Made Us Smarter"

A nice piece, to be filed under "duh".

"As we got more [meat], our guts shrank because we didn't need a giant vegetable processor any more. Our bodies could spend more energy on other things like building a bigger brain. Sorry, vegetarians, but eating meat apparently made our ancestors smarter — smart enough to make better tools, which in turn led to other changes, says Aiello."

This falls under the category of things which you would already know if you'd read Larry Niven.  It's a large category.

In one of his stories, discussing herbivorous intelligences, he asks the question, "How much intelligence does it take to sneak up on a blade of grass?"

Now anyone who's dealt with horses, for instance, knows they're not brainless, but it's a pretty good point.  Carnivores have a lot more pressure to evolve intelligence.

So the next time a vegetarian tells you we didn't evolve to eat meat, you'll know better.