In my chapter on the perils of bipedalism - called The Downside of Upright - I deal with theories developed by Harvard professor of evolution Dan Lieberman, and assorted colleagues, which posit that the ability for endurance running first evolved with Homo erectus, in the African savanna, some 2 million years ago. Lieberman points out that while these human ancestors were actually poor sprinters (in fact even Usain Bolt today could be outrun by a rabbit), they would have been able to literally run prey animals to death in the stifling heat, because they could dissipate heat through sweating whereas prey species could not pant and deep breathe at the same time - quickly exhausting them to the point where a bang over the head from a rustic club would have been more than enough to finish them off.
Now a group of scientists from the University of Cambridge have explored a possible link between exposure to testosterone in the womb, prowess at endurance running, and attractiveness to females. Such prowess "may have been used by females as a reliable signal of high male genetic quality during our hunter-gatherer past, as good runners are more likely to have other traits of good hunters and providers, such as intelligence and generosity." they say. One of the study's authors, Danny Longman, expands: “The observation that endurance running ability is connected to reproductive potential in men suggests that women in our hunter-gatherer past were able to observe running as a signal for a good breeding partner. It was thought that a better hunter would have got more meat, and had a healthier – and larger – family as a consequence of providing more meat for his family. But hunter-gatherers may have used egalitarian systems with equal meat distribution as we see in remaining tribes today. In which case more meat is not a factor, but the ability to get meat would signal underlying traits of athletic endurance, as well as intelligence – to track and outwit prey – and generosity – to contribute to tribal society. All traits you want passed on to your children.”
A copy of the full paper can be downloaded from the following DropBox link: https://www.dropbox.com/sh/vbhtt0u4175xmnc/AAAWmI5KEya9WiT1c8EsFzeNa?dl=0
The whole paper which is available from the open access journal PLoS 1.