As the thread: Why haven't the brain among different species developed in general to a size comparable to Homo Sapiens. And even though the brain among Neanderthal was considered to be bigger than Homo Sapiens, did the evolution considered that it was too "big" or too "clumsy" and the race died? Even though environmental factors and limits are definitive for the time span among species development, I think a bigger, more developed and advanced brain is both increasing social & survival aspects for a species, even though what species I'm referring to. Sure, there are limits for how big a brain can be since human anatomy demand a constant temperature , but wouldn't that "easy part" be adapted by the ambient environment? The nature has facilitated many obstacle for lifeforms around the world, why not the limitations for extended brain size? Or haven't the evolution "caught up" the time span? /An biological Enthusiast.