Did We Just Outrun the Bears Better?

You'd beat a Neanderthal in a race 

As the joke goes, if you and I were walking in the woods and we met an angry or hungry grizzly bear, I don't have to outrun the bear, I just have to outrun you.

There have long been claims that Neanderthals were weaker runners than modern humans, says David Raichlen of the University of Arizona in Tucson, but until now, there was no convincing evidence.

In runners, the tendon acts as an energy store, stretching like a spring as the foot lands then bouncing back to help lift it again. Raichlen reasoned that the more energy is stored within the tendon, the more efficient the runner.  He began by studying eight endurance runners on treadmills to find out how much energy they used at given speeds. By looking at MRI scans of their ankles, he found that the distance between a point on the heel bone just below the ankle bone, and the back of the heel bone where the Achilles tendon attaches, was proportional to the runner's efficiency. The shorter this distance, the greater is the force applied to stretch the tendon - and the more energy is stored in it. This means that people with shorter distances are more efficient runners, using less energy to run for longer.

Raichlen then turned to Neanderthal skeletons, and found that our distant cousins' heel bones were consistently longer than ours. Neanderthals, he concludes, would have lost a race against Homo sapiens (Journal of Human Evolution, DOI: 10.1016/j.jhevol.2010.11.002).

So, aside from the problem of angry bears (and husbands), how did Neanderthals lack of sprinting ability contribute to their downfall?

John Stewart of Bournemouth University, UK, points out that H. sapiens remains tend to be associated with animals from open habitats, while Neanderthals are found with animals from closed habitats. He and Finlayson believe that when the forests of northern Europe were wiped out by the most recent ice age, Neanderthals were squeezed out of existence as well.

Archaeological evidence shows that as ice advanced from 50,000 years ago, and northern Europe's dense forests became tundra, Neanderthals were pushed into small, isolated forest refuges in southern Europe. H. sapiens were able to adapt to hunting on the expanding European tundra. Neanderthals, says Finlayson, found themselves out of step with the environment while modern humans were perfectly suited to it. "We were in the right place at the right time," he says.

I'm not sure I'm buying all of this.  The last glaciation was just one of several similar glaciations over the last 600,000 years, and the Neanderthals had survived all of them, until about 30,000 years ago when "modern man", i.e. Cro-Magnon Man came on the scene.

The first proto-Neanderthal traits appeared in Europe as early as 600,000–350,000 years ago. Proto-Neanderthal traits are occasionally grouped to another phenetic 'species', Homo heidelbergensis, or a migrant form, Homo rhodesiensis.

By 130,000 years ago, complete Neanderthal characteristics had appeared. These characteristics then disappeared in Asia by 50,000 years ago and in Europe by about 30,000 years ago, with no further individuals having enough Neanderthal morphological traits to be considered as part of Homo neanderthalensis.

I think we did Neanderthal in, probably by a combination of competition for food and space, warfare, and a little bit of interbreeding.  You don't have to out run the bear...

...but it helps.