Stockholm, Sweden – The last woolly mammoths on Earth made their last stand on a secluded Arctic island roughly 4,000 years ago. The reason behind their extinction has long puzzled scientists, with a new genetic analysis pointing to a possible freak event like an extreme storm or a plague.
Contrary to a previous theory suggesting harmful genetic mutations from inbreeding caused a “genomic meltdown” in the isolated mammoth population, recent findings indicate that the real cause of their demise may have been a random catastrophic event. The research, led by Prof. Love Dalén of the Centre for Palaeogenetics, challenges the notion that the mammoths were simply doomed to extinction due to their small population and genetic deficiencies.
During the ice age, woolly mammoths roamed across vast regions of Europe, Asia, and North America before retreating northwards as the climate warmed and human hunters posed a growing threat. The population on Wrangel Island, however, persisted for an additional 6,000 years after the mainland extinction, providing an invaluable insight into the species’ fate.
By analyzing the genomes of mammoth specimens from both Wrangel Island and the mainland over a span of 50,000 years, researchers unveiled a population bottleneck on the island that dwindled to just eight breeding individuals at one point. Despite this, the group managed to rebound to a stable population of 200-300 mammoths until their eventual disappearance.
Compared to their mainland counterparts, the Wrangel Island mammoths exhibited signs of inbreeding and low genetic diversity, making them more susceptible to new pathogens like a plague or bird flu. The study’s first author, Marianne Dehasque, highlighted the relevance of mammoths in understanding ongoing biodiversity crises and genetic consequences of population bottlenecks.
Dr. Vincent Lynch, a biologist not involved in the study, emphasized that extinction, when not caused by humans, often results from a combination of factors such as inbreeding, small population sizes, harmful mutations, and unforeseen events. The research sheds new light on the final days of the woolly mammoths and underscores the importance of genetic diversity in species survival.