“I want a caveman, I want a brave man”

Posted on June 2, 2011

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Oh. My. God.

Wild Men? The First Fred Flintstones Were Left Holding the Baby yells the Daily Express.

Not much better, when you discount the popular culture reference, is the US News & World Report: Even Ancient Men Seemed to Like their Man Caves.

Urk. I cannot believe I just typed the words “man cave”. There, I did it again. Someone stop me…

USA Today manages to come up with an even more stereotypic angle: Human ancestors were Mama’s boys, their story is titled.

Lest we miss the point, Michigan’s ABC12 classified its version of the story (derived from the AP, with the title Wandering Women) under the heading “Bizarre News”, producing the unbelievably awful juxtaposition Bizarre News: Wandering Women.

The marginalization of the AP story is too bad, because the writer managed to get it basically right, while playing off stereotypes and popular culture in an amusing way:

Remember that old Dion song, “The Wanderer?” It was about a guy who would never settle down. But researchers say it was our female ancestors who did the wandering, while the males stayed put. A study in the journal Nature concludes that females from two pre-human species hit the trail. The researchers say it was probably to prevent inbreeding. The study analyzed mineral variation in fossilized teeth. Lead author Sandi Copeland, from the University of Colorado, says it would make sense for the males to stay put in order to develop a common defense.

The research, published in the June 2 edition of  Nature, is described without gender stereotypes by the New Scientist.

Strontium isotopes were analyzed in teeth from two African australopithecene species, Australopithecus africanus and Paranthropus robustus.

The distinction between more local (within 50 km) and less local (beyond 50 km) strontium isotopes could not, of course, be directly correlated with sex: tooth size was used as a proxy. Larger teeth turned out to be local; smaller teeth non-local. Assuming sexual dimorphism among australopithecenes is correctly understood, larger teeth should belong to males.

Lead researcher Sandi Copeland, of the Max Planck Institute, argues that australopithecene populations may have depended on male bonds for defense of territory, requiring females to move “to find mates among unrelated males”. This would make these human ancestors most like chimpanzees and bonobos, our closest primate relatives, which in itself is not entirely surprising.

What is neat, though, is to have concrete data about individual migration histories. That makes this research worth more than the treatment accorded it by the press.

The proposed social structure is acknowledged to be speculative, and among the uniformly positive assessments of the research, there is a great deal more variation about whether Copeland’s proposed explanation for the observed pattern is yet warranted.

Somewhat lost in the popular press spin is the fact that the pattern is not perfect:

eight of nine large-toothed individuals — presumably males — grew up in the area where they died, whereas at least five of 10 small-toothed individuals — thought to be females — grew up elsewhere

Science News tells us.

I actually find this variability more interesting, as it suggest something more complicated is going on.

The Vancouver Sun suggests that there are divergent opinions about how to interpret the data among the researchers themselves:

U.S. anthropologists on the team are depicting the males as “stay-at-home-kind of-guys when compared to the gadabout gals.”

Their British colleagues at Oxford University said the findings “suggests early cavemen had ‘foreign brides.’”

In other words: the British researchers emphasize male agency; the US researchers consider the agency of both males and females.  The majority– but not all!– males chose to stay locally– perhaps because they liked the locally available foods, the researchers suggest. Meanwhile, about half of the females at these sites grew up elsewhere, and so must have been motivated to travel longer distances.

Almost lost in the press coverage is the fact that the original research hypotheses were not concerned with sex differences at all. Instead, the researchers were expecting to find possible territorial differences between the two species, which overlapped in South Africa 1.8 million to 2.2 million years ago.

As Alan Boyle explains in MSNBC’s Cosmic Log,

Eight of the teeth came from the Sterkfontein Cave and were traced to a species known as Australopithecus africanus, dating back about 2.2 million years. The other 11 teeth came from the Swartkans Cave, and are attributed to Parathropus robustus, a species that lived about 1.8 million years ago. Australopithecus is thought to be a closer ancestor of modern humans than Paranthropus.

But the researchers found no systematic difference between the two species.

Rather, their data tells a story about tendencies toward greater and lesser mobility varying between larger and smaller individuals, a story that should be read, properly, as demonstrating that already at this early period, behavioral plasticity was high, not just between the sexes, but even within them.

We need to remember the one nonconformist male who came from somewhere else. We need to think about models that take into account that half of the females were from the local area.

None of that is helped by the kind of gender role stereotyping that the mainstream media indulged in.