You have to be brain-dead to deny the fact of Evolution these days. Well, these last 150 years actually… Apparently though, at least 40% of USians (other Americans are smarter), are indeed just so cerebrally demised. Hopped the neurological twig as it were. Zombified the gray matter. Deceased the thinking apparatus.
Now why would we worry? These are sister-shagging Bible belt rednecks who still think the South actually won the Civil War, aren’t they? ‘Oh no man we just kinda took a time out for a mint juleps n some grits n shit them gaddamn Yankees done called time on us!’ So who cares what they think?
There are two forms of Selection involved in Evolution. Both were described by Darwin.1 One is Natural Selection, which is the cumulative effect of the environment on organisms, and the other is Sexual Selection, which is how individual organisms choose their partners. Key to Sexual Selection is attraction: we select partners we find attractive. In humans, this is important, because we have overcome most of the environmental factors that impinge upon us.
While the effects of Sexual Selection are best known in domestic animals, where humans do the selecting, we have shaped ourselves through it, by choosing our sexual partners and at the same time, by making ourselves appealing to our targets.2
Cooking is now seen as the definitive characteristic of modern humans, from which all others followed. It seems to have directly led to the development of tools, especially blade design, but it had many other consequences.
Cooking, particularly of meats and fats but also starches, partially pre-digests the food, making more energy available to us and allowing us to use less to digest it. We put this extra energy into growing brains. Growing big brains burns many calories and just running them consumes a significant part of our daily food intake. We know that the physical structures which allow us to speak were evolving at the same time as our brains were growing larger. Speech allowed more complex and efficient communication and cooperation. This encouraged conceptual thinking and other intellectual skills, again leading to the development of bigger brains.