Tangled Roots
Mingling among Stone Age peoples muddies humans’ evolutionary story
http://www.sciencenews.org/view/feature/id/342924/title/Tangled_Roots
Of course, defining what a ‘species’ is is challenging to begin with. I am quite interested in human evolution and have read quite a bit on the subject over the years and have never really been sold on the idea that moderns humans drove the Neanderthals out (they appear to have been exceptionally well suited for their environment). However, if, as seems clearly the case based on this article, the two groups were capable of freely interbreeding (in which case I would not be so quick to call them separate species), it seems quite plausible to me that there would be some (perhaps quite a bit) of dallying with one another. Humans, as a group, tend to favor breeding outside of their local group (perhaps the reason why ‘exotic’ women tend to turn heads and attract attention the way they do), so it makes sense to me that there would be interbreeding. Given this article I would have to say that the differences between ‘Neanderthals’, ‘Denisovans’ and ‘Homo sapiens’ are nothing more than archeologists wanting to make a name for themselves. If they can interbreed (as seems clear from the DNA evidence) then the only reason they could be considered separate ‘species’ is if they failed to do so in proximity (such as lions and tigers), which belies the DNA evidence, or were simply separated by physical distance. Since ‘modern’ humans are such prolific travelers, clearly distance was easily overcome, so by my reckoning there is just the one species.
