http://www.digitaljournal.com/science/did-a-birth-defect-kill-the-mammoths/article/378770

Did a birth defect kill the Mammoths?

Posted Mar 29, 2014 by Tim Sandle
The woolly mammoths may have succumbed to a shrinking gene pool or intense environmental pressures as their species went extinct, according to a new study.
Model of a woolly mammoth In the Royal BC Museum in Victoria  Canada. The display is from 1979  and ...
Model of a woolly mammoth In the Royal BC Museum in Victoria, Canada. The display is from 1979, and the fur is musk ox hair.
Thomas Quine (CC BY 2.0)
The new research suggests that the last remaining populations of mammoths roaming the Earth became extinct around 10,000 years ago. These last remaining animals were beset with birth defects. The researchers speculate that the birth defects were the result of inbreeding or increased levels of prenatal stress caused by starvation or disease.
The reason why the scientists think birth defects were the cause follows the finding of several fossil vertebrae near the North Sea in Europe. These bones showed signs of cervical ribs, birth defects that can be a sign of widespread and serious developmental disturbances, Live Science has reported.
The shape of the necks shows a deformity, Frietson Galis, a paleontologist at the Naturalis Biodiversity Center in Leiden, who led the study has told The Scientist. These changes were likely the result of inbreeding between shrunken populations of the imperiled creatures, of maternal stress brought on by dwindling resources or disease, or both.
The findings have been published in the journal PeerJ; the paper is titled "Extraordinary incidence of cervical ribs indicates vulnerable condition in Late Pleistocene mammoths".