re: #211 Obdicut

Yes— because that provides an actual benefit.

There are definitely differences in metabolism of alcohol among humans— and metabolism of opioids, which are heroin. There are no drugs that exist that can affect us that don’t hook into things that have evolved.

There is no purpose to alcohol tolerance, evolutionarily. There is no benefit that it actually has. It is likely that the enzyme that helps bind ethanol evolved for some other purpose— probably dealing with intracellular ethanol.

We have enzymes that deal with opioids. We have enzymes that deal with ethanol.

Don’t fall into the trap of believing evolution is all about preserving only the beneficial. There are far too many complexities to how a species evolves to assume a trait only needs to be beneficial to be retained.

On a strictly selection basis, which is just part of the mechanism of evolution, a beneficial trait is most likely to be retained when the cost/benefit ratio is < 1. The ability to drink milk has a very low cost, it is just a delay in the triggering of a regulatory sequence and the benefit can be substantial. That isn’t true of alcohol.