Risk-tak­ing mam­moths died young

Sunday News - - WORLD -

STOCK­HOLM Time and again, from Ken­tucky to the Ber­ing Straits, woolly mam­moths ap­pear to have died af­ter blun­der­ing into nat­u­ral traps such as thin ice, mud­flows or pools. This has left palaeon­tol­o­gists won­der­ing why so many of these clumsy ca­su­al­ties were male.

A study by re­searchers in Swe­den and Rus­sia has shown that two-thirds of the mam­moth re­mains kept in mu­se­ums or sci­en­tific col­lec­tions come from bulls.

The sci­en­tists be­lieve that the males were more likely to get them­selves stuck in places where their corpses would be frozen or fos­silised for pos­ter­ity. They may not have been good at sur­viv­ing, but they had a gift for post­hu­mous self-preser­va­tion.

A team led by Pa­tri­cia Pec­nerova and Love Dalen, of the Swedish Mu­seum of Nat­u­ral His­tory, an­a­lysed sam­ples of DNA from 98 spec­i­mens across Siberia and found that 66 of them were male.

When they com­pared the sex ra­tios of mam­moths from Wrangel Is­land in the Arc­tic, where the last mem­bers of the species hud­dled to­gether be­fore dy­ing out 3600 years ago, and the vast ex­panse of the Rus­sian main­land, the ra­tios were roughly the same.

This means the ac­ci­dent­prone­ness of male mam­moths prob­a­bly had lit­tle to do with their habit of mov­ing far away into un­fa­mil­iar ter­ri­tory, be­cause the Wrangel Is­land males were con­fined in a rel­a­tively small space. The more plau­si­ble the­ory is that they were just not as savvy as the fe­males.

It is not, Dalen says, that the males were un­usu­ally thick. They were only do­ing what evo­lu­tion in­tended – wan­der­ing off on fool­hardy es­capades with their teenage mates.

Much like ele­phants, woolly mam­moths are thought to have lived in ma­tri­ar­chal herds dom­i­nated by fe­males and a sin­gle bull. Shortly af­ter the young males reached ma­tu­rity, be­tween the ages of 13 and 15, they tended to drift off in ‘‘bach­e­lor groups’’.

Dalen said it was likely that these ado­les­cents were driven by a strong ap­petite for risk, be­cause the rewards of seiz­ing con­trol of a herd were so great. This mix of rash im­pulse and so­cial iso­la­tion ap­pears to have sent many males to an early grave. The Times

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