Has Sin changed Humans Biologically?

I think there's an argument to be made that sin not only corrupts the soul of men but over generations even our genes.

We see this in nature. When the environment changes some individuals in an animal species survive and many die. Those who survive are often different from the survivors. Over a period of time this can warp a species into something quite different than what it began as.

Why should we assume this hasn't happened with humans as sin has altered our social environment?

How can we be sure that the Fall of man didn't have a gradual biological component as well as a spiritual one?

In the first generation after Adam we see the murderer (Cain) having many offspring while the innocent has none (Abel).

It seems likely to me that we as people would seem to be another species to those early people who had only recently been corrupted by sin. They had not suffered from generations of natural selection under the regime of sinful man.

This is why I'm not surprised when scientists link something we call "sin" to a biological predisposition. Why shouldn't sinful nature favor biological adaptations to the new sinful world we compete in?

I'm not offering eugenics (God forbid), I'm simply offering that we shouldn't be surprised that the lineage of mankind has become corrupt.