From an article by Roger Highfield, in "The Telegraph":
"Now a relatively new method has been used to work out the origins of the victims tossed into a mass grave of skeletons, and so distinguish one tribe from another, revealing that neighbouring tribes were prepared to kill their male rivals to secure their women some 7000 years ago."
Previous tests proved inconclusive; however a "new method was used to separate the victims by geographic origin, it was clear that the local group was special - local because it was the only group with any young children, and special because it was the only group without adult women, despite being the largest group.
The researchers conclude the absence of local females indicates that they were spared execution and captured instead which may have indeed been the primary motivation for the attack.
Interesting theories .....
Roger Highfield has written a couple of other articles that may be of some interest:
"Now it seems that the reason is that our prehistoric male ancestors kept female harems and fought over them to procreate: because male life was nasty, brutish and short, evolutionary forces focused on making males big and strong, rather than long lived.
The discovery is reported today [17th October 2007] in the Proceedings of the Royal Society Biological Sciences by Prof Tim Clutton-Brock of Cambridge University and Dr Kavita Isvaran of the Centre for Ecological Studies, Bangalore, India.
"Our prehistoric male ancestors kept female harems and fought over them to procreate: because the potential number of offspring was greater for males, competition for mates was severe. As a result, evolutionary forces focused on making males big and strong, rather than long lived.
Prof Tim Clutton-Brock of Cambridge University and Dr Kavita Isvaran of the Centre for Ecological Studies, Bangalore, India found that the difference in lifespan between males and females in creatures such as red deer, prairie dogs, lions, baboons, geese, mongooses, wild dogs, beavers and others grows in direct proportion to the degree to which an animal's society is polygynous, that is a society where one male enjoys the attentions of several female breeding partners.
Thus the very fact that men age faster and die younger than women suggests human Stone Age society was polygynous."