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Trên đường mòn của người Denisovan
05 Mar, 2024
DNA chỉ ra rằng loài người tuyệt chủng phát triển mạnh trên khắp thế giới, từ Siberia lạnh giá đến Tây Tạng ở vùng cao – thậm chí có thể ở các đảo Thái Bình Dương
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Neanderthals may have vanished 40,000 years ago, but they are no strangers to us today. Their stocky skeletons (bộ xương) dazzle in museums around the world. Their imagined personas star in television ads. When Kevin Bacon noted on Instagram that his morning habits are like those of a Neanderthal, he did not stop to explain that our ancient cousins interbred with modern humans (người hiện đại) expanding out of Africa.
But there’s no such familiarity with the Denisovans, a group of humans that split from the Neanderthal line and survived for hundreds of thousands of years before going extinct. That’s largely because we have so few of their bones. In a new review paper, anthropologists tally all of the fossils that have been clearly identified as Denisovan since the first discovery in 2010. The entire list consists of half a broken jaw (sái quai hàm), a finger bone, a skull fragment, three loose teeth and four other chips of bone.
The evidence offers a picture of remarkable humans who were able to thrive across thousands of miles and in diverse environments, from chilly Siberia to high-altitude Tibet to woodlands in Laos — perhaps even in the Pacific islands. Their versatility rivals our own.
Researchers there found part of a jaw dating back more than 160,000 years with Denisovan-like teeth. It also contained proteins with a molecular structure (cấu trúc phân tử) that might be expected from a Denisovan, based on their genes. The following year, the researchers reported that the cave floor contained Denisovan DNA.
But in the highlands, the Denisovan genes with the evolutionary (tiến hóa) advantage are active in the brain. Michael Dannemann, an evolutionary geneticist at the University of Tartu in Estonia who led the New Guinea study, speculated that at high altitudes in New Guinea, people might face periods of food shortages (thiếu lương thực). “You might have to adapt body parts that use a lot of energy, and one that consumes a lot of energy in humans is the brain,” he said.
source: nytimes,
Tags: Hồng Nhungscience
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