"Fire and tool use means that having a big brain becomes less of a disadvantage and more of an advantage now that you can feed it yea but you have to have the brains to build a fire before it becomes an advantage . sigh ."
"But a slightly larger brain than average is still feasible and offers enough of a benefit in a large social group that its worth the price - however something the size of a modern humans brain is far too demanding . That slightly larger brain can be supported by an organism or society that has n't developed fire , but is also able to discover the uses of it , from then on nutrician is n't the big limiting factor that restricts how big a brain can get from then on ."
"Fire and tool use means that having a big brain becomes less of a disadvantage"
"But a slightly larger brain than average is still feasible and offers enough of a benefit"