The final population of woolly mammoths on Earth met their demise through a sudden and mysterious event, according to a new study. This population, isolated on Wrangel Island in the Arctic for 6,000 years, was previously thought to have succumbed to genetic problems due to inbreeding. However, a new study has overturned this theory, leaving the cause of their extinction shrouded in even greater mystery.
The research, published in the journal *Nature*, analyzed the genomes of 21 mammoths, including 14 from Wrangel Island and 7 from the mainland population before their isolation. The study found that while the island’s mammoths did exhibit signs of inbreeding and low genetic diversity, these factors were not the primary cause of their extinction. The harmful mutations caused by inbreeding were gradually being eliminated from their genome, and while mildly harmful mutations accumulated, they were not severe enough to explain their demise.
This revelation suggests that the Wrangel Island mammoths, who grew from an initial eight individuals to a population of 300 before their extinction 4,000 years ago, likely succumbed to an unexpected event. “We can now confidently reject the idea that the population was simply too small and that they were doomed to go extinct for genetic reasons,” said Love Dalén, an evolutionary geneticist at the Centre for Palaeogenetics in Stockholm and senior author of the study. “This means it was probably just some random event that killed them off, and if that random event hadn’t happened, then we would still have mammoths today.”
The researchers believe that further investigation into unearthed mammoth fossils from the island’s final 300 years may shed light on the event that led to their extinction. This event, which occurred after the mammoths had thrived for 6,000 years, remains a mystery. “What happened at the end is a bit of a mystery still — we don’t know why they went extinct after having been more or less fine for 6,000 years, but we think it was something sudden,” Dalén said. “I would say there is still hope to figure out why they went extinct, but no promises.”
Despite the lingering mystery, the study’s findings carry crucial implications for understanding present-day conservation efforts. The researchers emphasize that simply increasing population size is not enough to prevent extinction. Active genetic monitoring is crucial to detect and address potential genomic vulnerabilities that may arise over time. “It’s important for present-day conservation programs to keep in mind that it’s not enough to get the population up to a decent size again,” said study first author, Mikkel-Holger Sinding, also an evolutionary geneticist at the Centre for Palaeogenetics. “You also have to actively and genetically monitor it because these genomic effects can last for over 6,000 years.”
This research serves as a stark reminder of the complex factors that can contribute to extinction and highlights the importance of ongoing research and proactive conservation strategies for protecting endangered species.
