Buzz
Many individuals have traces of Neanderthal DNA within their genetic makeup. Can commercial DNA testing services provide insight into the exact amount? Cristina Aries/Science Photo Library/Getty ImagesIf you're seeking more than what relatives or genealogical records can offer about your ancestry, genetic testing is a popular modern alternative. As detailed in the National Institutes of Health's ancestry testing primer, companies compare your DNA sample to their extensive databases from previous tests, searching for markers that reveal your ancestral roots. Techniques such as single nucleotide polymorphism testing are used, which identify variations across your genome. For instance, this can show that someone's ancestry is composed of X percent African, Y percent European, and Z percent Asian. But what about genes from another species entirely?
In addition to revealing the regions your ancestors came from, a few genetic testing services also tell you about genetic contributions from a different hominin species: Homo neanderthalisensis. After migrating from Africa, Homo sapiens likely encountered Neanderthals in the Middle East around 50,000 years ago, with evidence suggesting frequent interbreeding until Neanderthals went extinct about 40,000 years ago. Tony Capra, a biological sciences assistant professor at Vanderbilt University and a member of the Vanderbilt Genetics Institute, states that nearly all humans, except those of sub-Saharan African descent, carry some Neanderthal DNA, typically about 2 percent of their genome.
If you're interested in exploring your Neanderthal heritage, two well-known DNA ancestry services — 23andMe and Geno 2.0 — offer tests that include Neanderthal DNA analysis.
A 23andMe spokesperson, who wished to remain anonymous, mentioned in an email that the company began including Neanderthal DNA testing in 2011. This data is part of their standard test results, and it involves analyzing over 2,000 genetic markers that are known to have Neanderthal origins. This allows customers to compare their Neanderthal genetic variants with others worldwide.
As per 23andMe's website, the report provided shows both the quantity of Neanderthal variants detected and their specific locations on chromosomes.
Other DNA testing companies that were contacted by Mytour mentioned they either don't see enough demand for Neanderthal DNA testing or lack the necessary expertise to deliver accurate results. However, 23andMe, which uses a method developed by a scientist involved in the initial Neanderthal genome sequencing, has found that the Neanderthal DNA testing is one of its most popular features.
"We receive significant interest in this report, mainly for its entertainment value," the spokesperson shared. "Many customers enjoy sharing their Neanderthal results on social media, comparing them with family members, or having fun comparing their results with friends and even spouses."
Your Neanderthal heritage might also influence certain personal traits, although how much it affects you is a complex matter. Capra, a Vanderbilt researcher, co-authored a 2016 study that identified a specific segment of Neanderthal DNA which increased blood clotting, raising the risk of strokes and pulmonary embolism, while other Neanderthal genes were linked to traits like a higher likelihood of developing depression.
Capra explains via email, "Most people with Neanderthal DNA show little variation in the total amount they carry. However, significant differences exist in where that genetic fraction is located within the genome. Two people with 2 percent Neanderthal ancestry may have it positioned differently in their DNA. The key factor is not the percentage, but the exact portions of Neanderthal DNA you possess. This variation has helped us identify how certain segments of Neanderthal DNA contribute to specific traits — by comparing individuals with and without Neanderthal DNA at certain points in their genomes."
He further adds, "While Neanderthal DNA contributes to many traits, its impact is usually minimal. These traits are influenced by hundreds or even thousands of genes, many of which are not of Neanderthal origin. We’ve found that Neanderthal DNA has a noticeable but modest role. To fully understand genetic predispositions for these traits or diseases, a complete analysis of an individual’s entire genome is required."
Neanderthals were not the only human species with whom Homo sapiens interbred. A 2012 study revealed that our ancestors also mated with the Denisovans, another ancient group. In fact, about 6 percent of the genomes of modern people from Papua New Guinea come from Denisovans, suggesting that these groups crossed paths and interbred in central Asia before modern humans migrated to the South Pacific islands.
