

Why are Neanderthal and modern human skulls shaped differently?

Historically, scientists figured there were adaptive purposes at work: Neanderthals needed an architecture for the all-purpose tool of their extra-big teeth, while our own comparatively sunken faces were better for articulating complex languages.

These theories are plausible enough, reflecting both stereotype (Those simpleminded, oafish Neanderthals! No wonder they died!) and reality (thanks to language, humans are pretty darn smart). But evolution doesn't always have a good reason.

But University of California, Davis anthropologist Tim Weaver and colleagues compared skull measurements of 2,500 humans and 20

neanderthals, then contrasted the results with genetic data from another 1,000 people. The result of all the number-crunching? Natural selection doesn't appear to have anything to do with the difference.

We conclude that rather than requiring special adaptive accounts,

Neandertal and modern human crania may simply represent two outcomes from a vast space of random evolutionary possibilities.

There but for the grace of ... something ... go we.

Were neandertal and modern human cranial differences produced by natural selection or genetic drift?[Journal of Human Evolution]

Handsome By Chance: Why Humans Look Different From Neanderthals [Press Release]