A group of scientists from the United States, Sweden, Canada, and the UK, has sequenced and analyzed the complete high-quality genomes of two woolly mammoths (Mammuthus primigenius) – one from northeastern Siberia and the other from Wrangel Island, located in the Arctic Ocean. The results appear in the journal Current Biology.
This is an artist’s rendition of a woolly mammoth. Image credit: Flying Puffin / CC BY-SA 2.0.
The scientists produced the genomes from specimens taken from the remains of two male woolly mammoths, which lived about 40,000 years apart.
One had lived in Siberia and is estimated to be 44,800 years old. The other – believed to be from one of the last surviving mammoth populations – lived roughly 4,300 years ago on Wrangel Island.
“We found that the genome from one of the world’s last mammoths displayed low genetic variation and a signature consistent with inbreeding, likely due to the small number of mammoths that managed to survive on Wrangel Island during the last 5,000 years of the species’ existence,” said study senior author Dr Love Dalén of the Swedish Museum of Natural History.
“With a complete genome and this kind of data, we can now begin to understand what made a mammoth a mammoth – when compared to an elephant – and some of the underlying causes of their extinction which is an exceptionally difficult and complex puzzle to solve,” added co-author Dr Hendrik Poinar of McMaster University.
The team used sophisticated technology to tease bits and pieces of highly fragmented DNA from the ancient specimens, which they then used to sequence the genomes.
Through careful analysis, the researchers determined the mammoth populations had suffered and recovered from a significant setback 250,000-300,000 years ago. However, another severe decline occurred in the final days of the Ice Age, marking the end.
“The dates on these current samples suggest that when Egyptians were building pyramids, there were still mammoths living on these islands,” Dr Poinar said.
“Having this quality of data can help with our understanding of the evolutionary dynamics of elephants in general and possible efforts at de-extinction”.
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Eleftheria Palkopoulou et al. Complete Genomes Reveal Signatures of Demographic and Genetic Declines in the Woolly Mammoth. Current Biology, published online April 23, 2015; doi: 10.1016/j.cub.2015.04.007
