It would seem obvious that rising sea levels that cut off the last population of woolly mammoths on Wrangel Island from the Siberian coast 10,000 years ago caused in-breeding, leading to their eventual extinction. But a new genetic analysis, reported in Cell, counters that claim.
That result was unexpected, since an earlier report indicated that the mammoth population likely built up harmful genetic mutations, according to Love Dalén, a scientist with the Centre for Palaeogenetics of Sweden, and one of the paper’s authors.
“I was fairly surprised both at how few the mammoths on Wrangel Island were in the beginning (less than 10 individuals), and that we did not find any evidence for an accumulation of highly deleterious mutations,” Dalén says. He calls the relative lack of harmful mutations surprising, because an earlier paper published in 2017 in PLOS Genetics predicted they may have played a factor.