This is the blog for GW students taking Human Evolutionary Genetics. This site is for posting interesting tidbits on: the patterns and processes of human genetic variation;human origins and migration; molecular adaptations to environment, lifestyle and disease; ancient and forensic DNA analyses; and genealogical reconstructions.

GWHEG figure

GWHEG figure

Monday, February 24, 2020

Ancient DNA puts a face on the mysterious Denisovans, extinct cousins of Neanderthals


Today, the only Homo species walking on earth is us, Homo sapiens. In comparison, the late pleistocene could be imagined as the world of Homo where several hominin species were living at the same time. The one that sparks the most curiosity would most certainly be the Denisovans. Known only through genetic data and a few fossil fragments, how Denisovans look like remains mainly a mystery. However, many scientists are still itching to find out the morphology of this mysterious human species. 

Ancient DNA might be able to help ease this itch until more fossil evidence is discovered. Using a method based on epigenetics, researchers were able to compose the face of a Denisovans girl. In the process of DNA methylation, cytosine degrades overtime and researchers were successful in creating a methylation "map" using ancient DNA. They then compared the signals they retrieved from this map with modern human phenotype data and created the composite in the picture above. 

This research sheds new lights to the morphology of the cold-adapted Denisovans. However, as we know that even early Homo sapiens had various morphs, it is important to remember that phenotypic data derived from individual DNA might not be representative to the entire species. 

Ancient DNA puts a face on the mysterious Denisovans, extinct cousins of Neanderthals


Monica Cheung– Feb 24th, 2020

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