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The reconstructed Denisovan skull is broader than a modern human’s, as though stretched gently apart at the cheekbones. Science illustrator Maayan Harel, working with the scientists to interpret the study, used the skeletal approximation to sculpt a female Denisovan head.

Harel also painted a face. The illustration required some artistic freedom to produce “a face with the skin and eyes and this special gaze,” Carmel said. But it is “as accurate as we as we possibly could do,” he said.

Other research teams previously recovered DNA sequences from Denisovan and Neanderthal bones. Carmel and his colleagues looked for what’s called DNA methylation within those sequences.

DNA strands are built out of four basic building blocks, labeled A, C, G and T. The C type of DNA base can be tweaked with the addition of a methyl residue, which sticks to DNA like a parking boot on a wheel. Methylation alters a gene’s activity, often by turning it off.

Photo by Maayan Harel

Gene activity, not a raw DNA sequence, makes an organism what it is. “You can think about the frog and the tadpole: It’s the same DNA, it’s identical DNA, and yet they are two completely different creatures. One has gills. The other has lungs. One has legs. The other has a tail, and so on,” Carmel said. “And all these differences are not because of differences in the DNA sequence, but these are differences in gene activity patterns.”

The methyl molecule remains attached to DNA long after an animal has died, giving Carmel’s team a proxy for gene activity that took place 100,000 years ago. They studied methylation patterns in three human groups: from a single Denisovan, two Neanderthals and dozens of Homo sapiens, including five who lived thousands of years ago. The researchers also compared these methylation maps to chimpanzees’.