Wrangel island mammoths: Isolated survivors of genetic mystery

10,000 years ago, on Wrangel Island off the coast of Siberia, a unique population of mammoths began to form. Scientists published their findings in the journal "Cell" and speculated how these mammoths became extinct.

Scientists from the international research team found that rising sea levels cut off a few, a maximum of eight, of these prehistoric animals from the continent. As a result, mammoths survived on this isolated island for the next few thousand years.

Data analysis shows that over approximately 20 generations, the mammoth population on Wrangel Island grew to 200-300 individuals. However, their DNA studies indicated that these animals practised inbreeding, resulting in low genetic diversity.

Nevertheless, scientists believe these factors may not have led to their extinction. "These findings suggest that the mammoths were suffering from genetic diseases for hundreds of generations after the recovery," explains Love Dalén, an evolutionary geneticist from Stockholm University and co-author of the publication.

Dalén adds that the probable cause of the mammoths' extinction on Wrangel Island was an unforeseen event. If it had not occurred, the mammoths might still live there today.

The research team conducted a genomic analysis of 21 woolly mammoths — 14 from Wrangel Island and seven from the continental population. The samples covered the last 50,000 years of these animals' existence.

Compared to their continental ancestors, the genomes of Wrangel Island mammoths showed signs of inbreeding and low genetic diversity. The studies also revealed decreased diversity in a group of genes known to play a crucial role in immune response.

The genetic diversity of the island's population declined over six thousand years, but this process was slow. This suggests that the population size remained stable until its extinction.