Harrison W. answered • 01/04/20
PhD Neuroscience Student, BA Biology.
It seems pretty clear that human behavior continues to change, or at least be re-purposed, to manage new cultural and societal demands, but the degree to which those behavioral changes are due to genetic/neural changes is less clear. The question of epigenetics is an even more recent question, but there is on going research at many universities (including Emory Univerisity) to explore how epigenetic changes (non-nucleotide-sequence changes to gene expression) might underlie heritable changes in brain development, behavior, or the response of the stress-axis (hypothalamic-pituitary-adrenal axis).
Regarding the question of whether humans are still genetically evolving, I think the answer is of course yes, they are. Evolution never stops. Though human evolution may seem stalled on the incredibly short timescale of a few human generations, it's important to remember that evolution takes place on the scale of deep time. We can't conflate a period of relative environmental stability and low selection for an absence of evolution.
Humans may have implemented systems of altruism and social safety nets on a larger scale than other animals, abating some of the seemingly harsh immediate effects of natural selection, but that doesn't mean evolution has stopped. It's important to remember that the timescale of evolution is gradual, but lineages also experience periods of punctuated equilibrium, where more stable environments result in less rapid selection and changes in allele frequency (aka evolution). Even within the modern human era of seemingly slowed evolution it's likely that evolution is still proceeding by way of both sexual and natural selection, as the traits that made a human desirable 200,000 years ago are likely not the same traits that make a human fit or desirable today.
