Mammoth tusk in Siberia. Photo: Love Dalén
Mammoth tusk in Siberia. Photo: Love Dalén

“Lonely Boy” is the researchers’ name for the last woolly mammoth. We cannot know if he was really the last. However, at only 4,000 years old, he is the youngest specimen to have been found. When the climate heated up 10,000 years ago and sea levels rose, Wrangel Island became separated from Siberia. This left a group of a few hundred mammoths stranded on the island. While their relatives on the mainland then died out rather quickly, the island mammoths lived on. The last one died at roughly the same time that man was building the pyramids in Egypt.

Love Dalén and Marianne Dehasque put on protective clothing. Photo: Jens Lasthein
Love Dalén and Marianne Dehasque put on protective clothing before entering the new lab at the Center for Paleogenetics. In order not to contaminate the DNA being examined, the lab must be extremely clean. Photo: Jens Lasthein

Marianne Dehasque, doctoral student at the Department of Zoology, is working hard to sequence Lonely Boy’s DNA. This is a question of finding parts with well-preserved DNA uncontaminated by other organisms. Even though they may be several thousand years old, animals that have lain hidden in permafrost are often astonishingly well-preserved. Mammoths may have fur and soft tissue present. However, teeth, tusks and bones offer the best chance of finding DNA that has not degraded too far.

Model for the demise of endangered animals

Researchers are comparing the DNA of specimens from various periods of the 6,000 years the mammoths were isolated on Wrangel Island. Via this comparison, the mammoth can be used as a model for what happens to the genes of populations that are dying out. Will inbreeding lead to illnesses or to faster selection when sick animals die and their genes are not passed on?
“We don’t yet know why the mammoths died out on Wrangel Island. If it proves to be down to inbreeding, it’s unlikely that this also led to them dying out on the mainland. Nonetheless, it may mirror what is happening with currently endangered species. We have the opportunity to see how the genes of a small population change over a long period,” comments Love Dahlén, professor at the Swedish Museum of Natural History.
The mammoth project is one of many in which his research group is investigating how various populations have changed over time. Previous development of, for example, lemming, mammoth and Eurasian cave lion populations may indicate what happens when there is climate change and how species adapt or die out.

Read more

Old genes in new centre – about the new Center for Paleogenetics