> The point here is that paleo time was very long. About 2,3 million
> years. It
> is the evolutionary significant time in which we had our genes
> "formed".
> That is when our needs were formed. The realities that were present at
> that
> time formed us. The 10.000 years after is too short a time, too few
> generations to have changed any genes.
>

This is not quite true. One thing to remember is that our genes are
ALWAYS "behind the curve", playing catch-up to whatever new conditions
mother nature throws at us. Our genes were designed for some period in
the past, not whatever is occurring now, and this has always been the
case. Going from tropical Africa to glacial Europe must have been a big
stress, after those millions of years of tropical adaption, but it
happened, and in a quite short period of time, if the archeologists are
to be believed.

Back to the point. New genes don't need to form for a species to adapt.
If any small number of individuals has an adaptive gene already that
his fellows do not, over time that gene will spread. In conditions of
stress, famine or pestilence, when large parts of the population die,
beneficial gene variants can spread very quickly, going from rare to
predominant in a single generation.

In the case of milk, since it is a staple food in so many countries,
undoubtedly these super-selection events have occurred many times over
the centuries, as famines come and go. Since we are in fact adapted to
milk drinking over a many millions of years time span, I would guess
that the gene variants that allow for adult milk drinking were always
common in the population. Certainly men have always gotten milk as
adults!

By the way, the same logic works for grain eating. If any were adapted
to grain, it should be common now. That so many have trouble with
grains suggests that there was very little, weak and poor
pre-adaptation to grains prior to the neolithic. Milk and grains are
totally different in our level of adaptation.