It’s an interesting conundrum that I remember discussing with Nicholas Carr in the run up to his Google Making Us Stupid pieces. That is: has selection pressure (as operationally defined by sexual fitness) relaxed or at least qualitatively changed since our con-specifics were hunting and gathering? Seems to me that there are several questions embedded here:
First, modern humans emerged perhaps 50,000 years ago. Is that enough time for evolution to really make a difference? Further, the human technological advances that really start this discussion are at most only two centuries old. Is 200 years enough time?
Second, how exactly has selection pressure changed? From a selfish gene point of view, the rules haven’t changed even as we do live longer. Human traits are still selected for on the basis of the reproductive success of the trait holders. Neither the Internet nor our smart phones make any difference to that piece of the equation.
But might selection pressure change in the near future? Might we someday acquire attractive genes to acquire attractive traits? And how would those acquired genes play into reproductive success as opposed to some other kind of success (say economic)?
Finally, what about the role of epigenetics in selection? That is, might epigenetic modifications to genetic material have evolutionary consequences?
In any case, here’s a piece by Michael White on the question. Money quote:
Does this mean that we’ve transcended the messy process of evolution and made ourselves largely immune to natural selection? Not quite—just because our children aren’t eaten by predators or don’t succumb to childhood diseases does not mean that evolution has lost its power over our species.
Those genes haven’t lost their selfish personalities….
Discoverers and Discoveries 