When I made the part environment (including exercise and diet), part selection comment was partly motivated by a Scientific American article I read a couple of years ago. The article described differences in Mexican Indian skeletons from the periods before and during the Mexican takeover.
In comparison with earlier skeletons, those of the Indians enslaved by the conquistadors had two noticeable features: first, heavier bones, which was attributed to heavy forced labor, and second, worse teeth, which was attributed to a diet that had more corn and less meat. Clearly, these factors were environmental, not genetic, because the pre-and post- conquest periods were adjacent in time.
Thats very interesting...
Not sure I understand why that might be...you say forced labor: wonder how it differed from what they were doing previously. Longer hours maybe....