This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Between 29,000 and 19,000 years ago, the planet experienced some of its coldest temperatures and drastic landscape changes at the peak of the Ice Age, during the Last Glacial Maximum (LGM), the period of most extensive global ice cover. Humans, despite being unaccustomed to such icy temperatures and surroundings, survived through the age.
A recent study explored an age-old question: How did Homo sapiens thrive in extreme environments as they dispersed across Eurasia? The Jomon people lived across the Japanese archipelago for thousands of years, from around 16,000 to 3,000 years ago, long before the rise of farming. DNA extracted from 42 ancient Jomon remains helped researchers reconstruct where these people came from, understand how they adapted to extreme environments and identify the genetic legacy they left in people living today.
According to findings published in Science Advances, the Jomon genetic lineage separated from mainland East Eurasians between 27,000 and 19,000 years ago during the Upper Paleolithic period. As the Ice Age ended, rising temperatures and sea levels submerged land bridges, isolating the ancestors of the Jomon on the Japanese archipelago and locking in their distinct genetic trajectory. The researchers also found evidence that northern Siberian populations contributed to the Jomon gene pool, helping resolve long-running debates over how East Asia was first populated.
The Jomon also carried unusually high frequencies of three genes—UCP1, FTO and APOA5—involved in how the body stores and uses fat. These variants may have helped their brown fat turn fat into heat, allowing them to stay warm without shivering. One FTO variant linked to heat production is also strongly associated with higher BMI among modern populations.
Nearly three in four Jomon carried FTO gene variants, compared with one in five people in present-day Central Asia and Siberia who still carry these variants. Similarly, 29% of modern East Asians carry the APOA5 gene variant, compared with 89% of the Jomon. Around 50,000 years ago, Homo sapiens began moving through Southeast Asia and gradually into colder regions farther north.
During the coldest phase of the last Ice Age, they faced extreme environmental pressures—but many survived and made it through to the other side. Scientists have long known that some populations endured the Last Glacial Maximum. The bigger question was how.
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