Neanderthal Genomes and Autoimmune Diseases: DNA Says it All

Two new studies on Neanderthal DNA show that their genetic makeup may indeed exist in the modern genomes of humans. In fact, researchers believe that this genetic relationship is far greater than previously believed, according to recent findings.

The conclusions come from two separate papers that identify slices of the genome and how contemporary humans inherited the information from Neanderthals much shorter, stockier hunter-gatherers who went extinct a mere 30,000 years ago.

However, Homo sapiens and Neanderthals share a common ancestor that may have inhabited Africa more than a half a million years ago, according to background information from the studies. The acestors of Neanderthals were the first to move to Europe and Asia while the modern-human lineage stayed in Africa. However, as modern humans began to leave the continent less than 100,000 years ago, they interbred with the Neanderthals.

"These were bits of the genomes that had not seen each other for half a million years," said David Reich, a population geneticist at Harvard Medical School in Boston, Massachusetts, who led the study along with colleague Sriram Sankararaman, via Nature. "That's something that doesn't happen in human populations today."

Lineage from our Neanderthal ancestors may be responsible for a number of diseases that afflict us today-including variants of Neanderthal genes that can increase the risk for such diseases as lupus, biliary cirrhosis, Crohn's disease and even type 2 diabetes.

The findings suggest that Neanderthal DNA makes up approximately 1 to 4 percent of the genomes in people who live outside of Africa. Though this may seem a small amount, it still can make a significant affect in the structures of our skin, hair and even how we as humans survive in certain environmental conditions. 

"Now that we can estimate the probability that a particular genetic variant arose from Neanderthals, we can begin to understand how that inherited DNA affects us," said David Reich, a professor of genetics at Harvard Medical School who worked on the findings, according to National Geographic. "We may also learn more about what Neanderthals themselves were like."

More information regarding the findings can be seen via the journals Science and Nature.