I'm wondering, is this from marks on their bones from wounds? Or the fact that their bones were so strong?
I think it's both but mainly due to the thickness of the bone. Cordain and others explain how the bone gets very mildly damaged by sport activity(like muscle) and when it repairs itself numerous times after very heavy physical activity, it becomes much thicker.At any rate, every study on the subject indicates that Palaeo humans were at least as good as modern athletes or better, judging from the evidence re bones.
And I certainly heavily disagree re the notion that people have evolved beyond the level of palaeoman. Not only is this unlikely given lack of adaptation to many foods(try eating raw grains, for example in large quantities), but scientists have actually suggested that palaeoman was more advanced on the evolutionary scale than modern man. For example, we have smaller brain-sizes than palaeoman(8-11% less, depending on intepretation of dates), but also palaeoman was, most of the time, subject to a high degree of natural selection along with a combination of living in largely isolated communities, and those 2 factors(not present in Neolithic times) would have ensured a higher level of evolution. By contrast, we are now actively promoting the continued survival(and breeding) of people with cystic fibrosis and other genetic diseases, which means we are progressively becoming sicker as a population.