How Neanderthal DNA Impacts Modern Humans
In groundbreaking work, Joshua Akey, an evolutionary biologist, undertook the challenge of discovering and tracing the Neanderthal genome sequence. The study provided the opportunity to look more closely at the relationship between ancient hominins and the early ancestors of humans.
Neanderthals lived in Eurasia for as long as 300 millennia. About 60,000 to 70,000 years ago, early human ancestors left Africa and traveled to Europe and Asia, mating with the Neanderthals. Some of these offspring remained in the area to pass down this genome sequence to modern humans. Through DNA testing, researchers are able to estimate that as much as two percent of the DNA in people with Eurasian ancestry is from those original Neanderthal pairings.
Two Separate Research Findings
One of the interesting things about this information is that it was found through two independent reports. In addition to Josh Akey's work at the University of Washington in Seattle, David Reich at Harvard Medical School also completed the same study.
The two groups used different research methods and published in different journals, but they found the same information. Thanks to the different statistical approaches to identifying the DNA as Neanderthal, the two reports acted as validation for each other, eliminating doubt about the results.
What This Means
There are some interesting findings from these Neanderthal genome studies. For example, the Neanderthal base pair differences from human base pairs are mostly in regulatory sequences, which means they impact how the gene is expressed, not the actual genetic code.
Skin biology is one of the expressions influenced by the presence of Neanderthal genotypes. For example, people with these genes tended to have skin biology that was designed for the colder climates and lower levels of ultraviolet light compared to those without the Neanderthal genome. These traits include lighter skin and hair color than those individuals without Neanderthal genome sequences.
By comparing the genotypes with large database information on phenotypes through genetic testing and electronic health records in the eMerge (Electronic Medical Records and Genomics) Network, researchers were able to find specific links.
Some of the links discovered in this study included:
- Various autoimmune conditions
- Different immune responses
- Possible metabolic effects, including obesity and malnutrition
- The growth of non-cancerous skin tumors
Interesting research into the immune functioning of the Neanderthal sequences may help scientists develop ways to boost immune responses naturally. Early humans and human ancestors had to rely on their immune systems to fight off pathogens and disease. The stronger immune systems provided longer life cycles and increased chances of reproducing and passing on the trait.
More research into Neanderthal genotypes and the resulting phenotypes is still needed, and these studies are ongoing. One of the challenges is the grouping of the genotypes of Neanderthal variants to create a given phenotype. This creates a challenge in separating the genetic material and identifying the specific sequence for each linked trait.
To find out more about your potential link to Neanderthal ancestors, Genomelink offers information on several reports that use your raw DNA data. Browse the report options and choose one to learn more.