The Last Woolly Mammoths Reveal Clues About Their Extinction

New research sheds light on the extinction of woolly mammoths, guiding our understanding of this historical event.

Background of the Woolly Mammoth’s Extinction

Four thousand years ago, the last woolly mammoth took its final breath. Recent data reveal that the common belief regarding their extinction is likely inaccurate. This species thrived on Wrangel Island, situated off modern-day Siberia. Their isolation may have increased inbreeding risks, but that alone did not cause their demise. Inbreeding occurs when closely related individuals reproduce, often leading to offspring struggling to survive or reproduce.

A recent study confirms that the mammoth herd experienced inbreeding. However, data indicate that this genetic isolation may not have directly led to extinction. Over time, the Wrangel Island herd shed harmful genetic mutations, suggesting an unrelated event caused their extinction.

Significant Findings from Recent Research

Published in the journal Cell, the study emphasizes that the inbreeding issue may have been less significant. Joshua Miller, a paleontologist from the University of Cincinnati, calls the findings "remarkable." The insights reveal much about Wrangel's mammoths and show how genetic studies can benefit today's endangered species.

Scientists argue that woolly mammoths faced problems after being separated due to rising sea levels. Forces like environment variations could reduce genetic diversity, progressively harming isolated populations. Love Dalén, an evolutionary geneticist and contributor to the study, explains the important role of genetic variability in species survival.

Genetic Analysis of Woolly Mammoths

Dalén and his colleagues collected tusks, bones, and teeth over the years. From these remnants, they extracted DNA. Through their hard work, they analyzed genomes from 21 individual mammoths over the last 50,000 years.

Using computer simulations, they compared these mammoths’ DNA with modern elephants. This helped scientists to evaluate harmful mutations’ effects. They found that the initial herd size was small, starting with only eight individuals. However, they grew substantially, with numbers reaching 200 to 300.

The most severe mutations lessened over generations, indicating reproductive challenges linked with these changes. Vincent Lynch, an evolutionary biologist at the University at Buffalo, emphasizes that worsening genetic variation wasn’t the direct cause of extinction. Yet a mix of small mutations likely contributed vulnerability towards threats, such as diseases and climate shifts.

Ongoing Mysteries of Extinction

Unfortunately, researchers could not retrieve high-quality DNA from the last mammoths. Thus, their final moments remain elusive. Dalén shares that external disasters might have ended the mammoths' fate abruptly. Had circumstances been different on Wrangel Island, mammoths could be roaming even today.

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