As I understand it, birth defects are like 99.999% of the time unhelpful. But that 0.0001% of the time the genetic freak is a huge advantage and that gets passed down in the gene pool and thus, over many many generations, evolution.
Alcohol, which is known to increase birth defects, should increase the speed at which that happens. Right? Like playing the lottery with more tickets.
Of course!
You need to have evolutionary pressure to have directed evolution, and “alcoholism is a disadvantage” is as good as any. By drinking more, one reduces their and their kids’ chances to survive, making those alcoholic genes less frequent.
By the way, I hear propensity to alcoholism is also an inheritable trait.
I wonder if that cuts the wrong way in humans.
Alcoholism generally keeps people down societally, but I imagine a shitload of babies are born because drunk people didn’t worry about a condom