NOV 02, 2020 5:08 AM PST

Denisovan DNA Recovered From the Tibetan Plateau

WRITTEN BY: Carmen Leitch

Scientists recovered mitochondrial DNA (mtDNA) from a hominid species called Denisovans from samples of sediment excavated from Baishiya Karst Cave (BKC) on the Tibetan Plateau. The researchers determined that the group of Denisovans represented by these samples are closely related to ones identified at Denison Cave in Altai, Russia. Their work, which suggests that Denisovans lived on the Tibetan Plateau for long enough to adapt to high altitudes, has been reported in Science.

The first Denisovan fossil was discovered in 2010 by researchers led by Professor Svante Pääbo, and suggested that Denisovans were widespread in the area in the late Middle Pleistocene. Denisovans are hominins, a tribe in the subfamily of Homininae, which includes humans and chimpanzees.

Investigators led by Professor Chen Fahu at the Institute of Tibetan Plateau Research (ITP) of the Chinese Academy of Sciences (CAS) started recovering artifacts, bones and other samples from BKC. The artifacts were simple, and animals like gazelles and foxes were in the upper layers, while hyenas and rhinoceros were predominant in lower layers. Some animal bones bore cut marks, suggesting that humans had been living there for some time.

The researchers used radiocarbon dating on bone fragments and sediments from different layers of the excavation. This effort suggested that the deepest layers carried simple stone artifacts that were over 190,000 years old, while sand and stone artifacts from upper layers built up over years until about 45,000 years ago, or later.

In this work, the scientists analyzed 35 samples of sediment and extracted any mtDNA they contained. They identified 242 types of mammalian and human mtDNAs, and have expanded our catalog of DNA from ancient hominids.

Human mtDNA associated with Denisovans was found in samples that were deposited in the layers between about 60,000 and 100,000 years ago. Hominid mtDNA from about 60,000 years ago was found to share the closest links to Denisovan DNA found in Russia. The human mtDNA fragments from about 100,000 years ago were more separated, however.

Collecting sediment DNA samples (YAO Juanting and CHEN Xiaoshan) / Credit: HAN Yuanyuan

This genetic evidence shows that Denisovans did not only live in the area we now know as Siberia. They seem to have also adapted to life on the Tibetan Plateau. There are still many things we don't know about these hominins, however. Top layers of the sediment have been mixed, so we can't know whether these Denisovans were around long enough to encounter modern humans, for example.

Sources: AAAS/Eurekalert! via Chinese Academy of Sciences Headquarters, Science

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
AUG 23, 2020
Genetics & Genomics
Genetically Engineered Mosquitoes Will be Released in Florida
AUG 23, 2020
Genetically Engineered Mosquitoes Will be Released in Florida
After years of development, testing, and regulatory approvals, a genetically engineered mosquito will be released in Flo ...
SEP 21, 2020
Neuroscience
Scientists Compare Structural and Functional Evolution with First Atlas of Cavefish Brains
SEP 21, 2020
Scientists Compare Structural and Functional Evolution with First Atlas of Cavefish Brains
Cavefish are fish that dwell in caves, unable to access the outside world. Often, they were separated from their closest ...
OCT 11, 2020
Genetics & Genomics
Using Terahertz Waves to Control Gene Expression
OCT 11, 2020
Using Terahertz Waves to Control Gene Expression
Terahertz waves sit in the far infrared/microwave portion of the electromagnetic spectrum, and can be generated by power ...
OCT 15, 2020
Genetics & Genomics
Gene Variants Influence Aging and Mobility in the Elderly
OCT 15, 2020
Gene Variants Influence Aging and Mobility in the Elderly
Small changes in a gene that is involved in controlling the levels of the neurotransmitter dopamine could influence how ...
OCT 22, 2020
Cell & Molecular Biology
How a Gene Variant Raises the Risk of Multiple Sclerosis
OCT 22, 2020
How a Gene Variant Raises the Risk of Multiple Sclerosis
Now that sequencing the whole human genome is easier, faster, and cheaper than it used to be, scientists have been able ...
OCT 27, 2020
Immunology
The Genetics of Skin Inflammation, Seen With Unprecedented Clarity
OCT 27, 2020
The Genetics of Skin Inflammation, Seen With Unprecedented Clarity
A recent study published in Immunity details MIT scientists’ exploration of the underlying mechanisms of inflammat ...
Loading Comments...