THE NATURE'S TAP : PRECIS

 

The last stand of the mammoths. Tiny herd probably had genetic abnormalities that led finally to extinction.

When the Wrangel Island mammoths disappeared 4,000 years ago, mammoths became extinct for good.

For two decades, Love Dalen, a geneticist at Stockholm University, and his colleagues have been extracting bits of DNA from fossils on Wrangel Island.

In recent years, they have gathered entire mammoth genomes. Last month, they published a reconstruction of the genetic history of these enigmatic animals.

The scientists concluded that the island's population was founded about 10,000 years ago by a tiny herd made up of fewer than 10 animals.

The colony survived for 6,000 years, but the mammoths suffered from a host of genetic disorders.

Oliver Ryder, the director of conservation genetics at San Diego Zoo Wildlife Alliance, said the study held important lessons for trying to save species from extinction today.

It shows that inbreeding could cause long-term harm.

The World Students Society thanks Carl Zimmer.