Ancient Male Wooly Mammoths Lacking Female Leadership Wound Up Dead

Life was dangerous for males without a female to guide them.

Flickr / rpongsaj

The clumsy man who needs a woman’s help to survive has become something of a trite stereotype. Look no further than primetime family sitcoms like Modern Family or The Simpsons for examples of a boorish man who’d probably be dead from his own mistakes if not for his responsible wife. Problematic as this stereotypical portrayal may be, a Current Biology study published Thursday suggests it seems to bear out in one of our distant mammal relatives.

The international team of geneticists, archaeologists, geologists, zoologists, and ecologists behind the study report that, according to their DNA research on wooly mammoth (Mammuthus primigenius) fossil remains, male woolys were much more likely to die from accidents. They suggest that this happened because the way mammoth social structures were set up deprived inexperienced males of female leadership.

In their sample of 98 wooly mammoth fossils collected in Siberia, the team used paleogenomic sexing to establish that 69 percent (nice) of the sampled fossils are from males, whereas only 31 percent came from females. What struck them as odd was that there was such a disproportionately high number of intact male fossils and relatively few female ones.

This table shows the sex distribution of mammoth fossil samples from Siberia. As you can see, there's a huge difference between males and females.

Pečnerová et al

Mammals (including mammoths’ living relatives, elephants) typically exhibit evenly matched sexual distribution, so the fact that 69 percent of the fossil samples came from males was strange. Sexual dimorphism — the observation that male and female individuals of the same species have different physical characteristics, such as size — is an unlikely explanation for the disparity since members of both sexes left huge carcasses behind.

Something, then, must have happened during the preservation process to skew the sex ratios. The scientists argue that the higher rate of male fossil preservation was the result of more males dying of accidents that preserved their fossils — like falling into pits of ice or mud. The females, meanwhile, died out in the open more often, leaving their remains exposed to erosion by the elements, preventing fossilization or permafrost preservation.

“Therefore, one possible explanation for the skewed sex ratio that we observe in our samples could be that samples preserved for thousands of years in permafrost represent, to a disproportionate extent, male mammoths that have died in these types of natural traps,” write the study’s authors. “However, why males would die more frequently than females in such traps remains to be answered.”

They have some ideas, though.

This mammoth tusk was found on Wrangel Island, off the coast of Siberia.

Patrícia Pečnerová

The higher accident rate among inexperienced males, the researchers suggest, could be explained by a lack of female leadership among wandering males. We can use modern mammals, especially elephants, as a model for this social structure. A common habit among mammals is “male dispersal,” in which female members of a group are geographically restricted by tending to their offspring, whereas males often wander to areas with less sexual competition. If young male mammoths wandered the planes of Siberia, they likely encountered environmental hazards like mud pits and thin ice that they hadn’t been taught to properly navigate.

That being said, there’s no solid evidence to confirm this hypothesis, and there may well never be. But that’s how scientists must study extinct animals, By using the available fossil evidence and comparing mammoth death habits to modern elephants social structures, the scientists suggest that male mammoths could have benefited from some feminine wisdom and experience.

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