>
> Right, so when I ask whether "rapid evolution" is the mechanism that
> advocates of neolithic foods like dairy use to explain why these foods would
> be healthy, I'm not referring to the weeks or months it takes for genetic
> changes to occur in mosquitoes bombarded by pesticides, I'm referring to the
> hypothesis that significant human digestive adaptations could take place in
> under 30 to 40 thousand years.
>

Depends. What is 'significant'? Adapting to adult milk drinking
wouldn't seem to me to be much of a change. Adapting to drinking some
other species milk might be though.

Adapting to a type of food previously foreign, like grain, harder
still. But we are omnivores, so we are adapted already to a very wide
range of foods. Being able to get by in  a pinch on whatever awful
food is out there is one thing, going from there to making one of
these emergency foods the main staple is something else.

Personally I suspect that grain was always part of the diet in small
amounts. So a certain amount of adaptation is built in, if true.
Middle Eastern peoples are probably well adapted to Middle Eastern
grains like wheat. Maybe Europeans are adapted more to oats or rye,
Chinese to rice and millet etc.