Stephan Schuster lab, Penn State

This is not any old hairball. It is a very old hairball. It comes from a woolly mammoth that was buried in the Siberian permafrost. An analysis of its DNA, and the DNA from 17 other mammoths, by Stephan Schuster, of Pennsylvania State University and published in the Proceedings of the National Academy of Sciences, suggests the species was composed of two genetically distinct groups. One of these groups became extinct 45,000 years ago, well before people arrived in the area mammoths inhabited. That re-opens the question of whether it was people or climate change that finally did the species in.