Can different gravities cause physical and mental variations in the same race over time?
Were humans to settle on another planet that had a stronger gravitational effect on us, then I would imagine that the effects on the human body would include increased bone density and muscle mass. The extra work done against gravity even whilst standing by the extensor muscle groups would be akin to a constant moderate workout (depending on the increase in gravity of course). In essence you would be walking around with extra weight, and similar to if you walked around with a weighted backpack as military training exercises do, your muscles would hypertrophy over time to be able to better cope with the additional burden. Your bones would also have to cope with the additional stresses put upon them. There might well be increases in bone density to produce a stronger matrix, as osteoblast activity would increase, again to cope with the extra stresses. However, the actual nature of the bone matrix produced may differ from currently, as the ideal solution would cause the bone to weigh less
