Its been clear for a long time that there are mechanisms for retaining environmentally acquired changes in the genetic code and not simply through crude and aimless natural selection.
I’ll never forget how theatrical my Genetics 101 teacher at UC Berkeley 1963 appeared when he departed from his usually dry lecture style to rail like a holy man against Lysenko. It seemed inappropriate, for a general survey course, to get that carried away by an obscure bit of heretic genetic theory. His self righteousness, seen from a 50 year perspective, says a lot about what is wrong with academia today.
But to a certain extent, some of this COULD be explained by crude and aimless natural selection.
Suppose in some medieval European village there were two men, neither who had yet fathered children. And then there was a terrible famine. Man 1 burned through his daily calories very efficiently, and man 2 did not. Man 2 had a gene that limited insulin’s ability to be absorbed into the body’s cells while man 1 had no such problem. Because of this, man 2 has gained a little weight by not burning all his calories. His liver is also affected, storing extra sugar. His metabolism is down, and he’s often sleepy and non-energetic, even to the point that some think he’s lazy.
However, now, due to this famine, man 1’s reduced diet makes him succumb to starvation, but man 2 hangs on a little longer. The winter wheat crop finally does not freeze solid this winter, and the famine is over. Man 2 gets to pass on his genes, even this problematic insulin resistance gene, while man two, of course, being dead, does not.
Anyways, that’s not saying events occurred this way, only how natural selection could still be the driving factor.