데니소바인, 머리만 큰 게 아니었다! [강석기의 과학풍경]

Genetic information and the flow of material and energy are the two elements sustaining life. Any disruption in the flow leads to aging, illness, or death. However, genetic information can be preserved for long periods if the right conditions are met. The development of techniques to decipher the genetic code of a sealed genome, as well as its resulting protein sequences, has revolutionized paleontology and human studies.

One notable example is the deciphering of the genomes of Neanderthals and Denisovans, which coexisted with modern humans approximately 40,000 years ago.

Denisovan remains are scarce, consisting mainly of a baby's finger and adult toe bones. This scarcity prevented the extraction of DNA from these remains, leaving the physical appearance of Denisovans unknown. However, Denisovan bones have since been discovered in various parts of Asia, with only a few finger bones, fragmented thigh bones, and limited cranial and lower jaw fragments known so far. As a result, the only confirmed features of Denisovans were their large heads and fingers.

In 2019, three human bones (a lower jaw, a big toe bone, and a molar tooth) were found in a net pulled from the waters around Taiwan's Penglai Strait. The location was shallow, indicating that it was land during the ice age. In the previous year, Taiwanese and Japanese researchers analyzed the proteins in the lower jaw bone and confirmed it as Denisovian.

Last month, a joint study by Taiwan and Japan published a follow-up paper confirming that the big toe bone and molar tooth, also found in the Penglai Strait, belonged to Denisovans. Based on bone length measurements, the big toe bone belonged to a person around 180 cm tall, while the molar tooth was likely from someone as tall as 190 cm.

While only two individuals have been identified so far, their cranial and finger bones were notably large, suggesting that Denisovans were robust humans.