Uncovering the Past: Scientists Discover Rare Mammoth Tooth and Extract Ancient DNA!

Researchers have recently made an exciting discovery: the oldest-known woolly mammoth fossil in North America. This 216,000-year-old tooth was found along the Old Crow River in Canada’s Yukon Territory. It’s fascinating because it shows that woolly mammoths (Mammuthus primigenius) arrived in North America much earlier than scientists believed—over 100,000 years earlier, in fact.

Camilo Chacón-Duque, who led the study at the Centre for Palaeogenetics in Stockholm, emphasized how unusual this find is. Most fossils from this time in North America belong to other mammoth species that came before the woolly mammoths. He noted, “To our knowledge, the Old Crow mammoth is the oldest North American mammoth fossil that can be confidently identified as a woolly mammoth.”

The research team didn’t stop at finding the fossil; they also extracted DNA, revealing a treasure trove of genetic diversity from various mammoth lineages over the past million years. According to a statement from Stockholm University, this study helps shine a light on the complex ancestry of these ancient creatures.

Interestingly, the DNA from the Old Crow mammoth is among the oldest samples analyzed. However, it is outdone by even older DNA from Russia, estimated to be about 1.3 million years old. The team published their findings on April 9 in the journal Molecular Biology and Evolution.

Mammoths actually have roots tracing back to tropical Africa, closely related to modern elephants. They began moving into the cooler Northern Hemisphere around 3 million years ago, evolving to thrive in much colder environments. For this study, the team analyzed 34 new DNA samples along with data from over 200 previously published samples. Chacón-Duque highlighted the importance of these new samples, which were sourced from places like Siberia and North America.

The researchers used mitochondrial DNA, which is passed down from mothers. To date these samples accurately, they combined traditional radiocarbon dating with a novel approach called molecular clock dating. This method estimates the age of DNA based on mutation rates over time. Chacón-Duque shared that refining this technique was a significant challenge, but it led to accurate age estimates that matched well with geological data. “It was a very exciting moment for me,” he said.

The study’s revelations extend to understanding when mammoths first arrived in North America. Early migrations were made by Columbian mammoths (Mammuthus columbi) about 1.5 million years ago. They were quite large, towering up to 13 feet tall, compared to the woolly mammoths, which stood around 11 feet. Yet, much remains unknown about the lives of both species in North America.

Woolly mammoths are believed to have evolved in eastern Siberia about 700,000 years ago. The prevailing theory suggested they migrated from Siberia to Alaska between 120,000 and 10,000 years ago. However, the Old Crow find indicates they may have been in North America for over 200,000 years—much longer than previously assumed. This aligns with past genetic research hinting at their presence as far back as 400,000 years.

The research reveals that climate has played a major role in mammoth diversity over epochs. According to Chacón-Duque, “During warm periods, mammoth diversity seemed to retreat to refuges but spread again during colder times like the ice ages.” Most mammoths went extinct at the end of the last ice age around 10,500 years ago, but some isolated populations lingered in Alaska and Siberia until about 4,000 years ago.

This study not only sheds light on mammoth history but opens up new avenues for understanding how ancient species adapted to changing environments. It also speaks to the broader impact of climate on biodiversity, a topic that remains vital in our current era.

For a deeper dive into the evolution and history of mammoths, you can explore more through the Natural History Museum’s research.

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