The woolly mammoths that once roamed the Earth met their demise about 4,000 years ago on a remote Arctic island. The reason for their extinction has long been a mystery, but new genetic analysis suggests that a rare event, like an extreme storm or a plague, might have been the cause. This challenges the previous theory that harmful genetic mutations from inbreeding led to their downfall.
Researchers found that the mammoth population on Wrangel Island had low genetic diversity but had been stable for thousands of years before disappearing suddenly. This contradicts the idea that their small population size was the main reason for their extinction. Professor Love Dalén, an evolutionary geneticist, stated that it was likely a random event that wiped out the mammoths. If that event had not occurred, mammoths might still exist today.
Woolly mammoths used to roam Europe, Asia, and North America during the ice age. As the climate warmed and human hunters became a threat, they moved northwards and eventually went extinct on the mainland 10,000 years ago. A group on Wrangel Island survived for an additional 6,000 years due to rising sea levels cutting them off from the mainland.
The genetic analysis of mammoth specimens from Wrangel Island and the mainland revealed that the population on the island went through a severe bottleneck with just eight breeding individuals at one point. However, they managed to recover and maintain a stable population of 200-300 mammoths until their disappearance. The genomes of the island mammoths showed signs of inbreeding and low genetic diversity, making them more vulnerable to new pathogens.
Dr. Vincent Lynch, a biologist not involved in the research, highlighted that extinction is usually caused by a combination of factors, including inbreeding, small population size, harmful mutations, and sometimes, bad luck. This study provides new insights into the final days of the woolly mammoths and how a genetically compromised group might have been unable to adapt to environmental changes like new pathogens.
Understanding the fate of the woolly mammoths can shed light on the ongoing biodiversity crisis and the genetic consequences of a population bottleneck. The study of these ancient creatures can help us learn more about how species respond to challenges and how we can prevent similar extinctions in the future.
