Sunday, May 26, 2013

Got Neanderthal DNA?

Do you know how much of your DNA is Neanderthal? You can find out at 23andMe. Actually my reported 2.5% is below the 2.7% average for those of European descent in which most of the surviving Neanderthal DNA is found today. You can find out many more useful things about possible living cousins, your health and deep ancestry for $99. The Neanderthal thing is more of a curiosity now; but could it mean anything? No one knows yet. Here is what 23andMe currently reports to me:

An estimated 2.5% of your DNA is from Neanderthals.
Dave Dowell (you)2.5%
22nd percentile
Average European user

  • Higher brow
  • Narrower shoulders
  • Slightly taller

  • Heavy eyebrow ridge
  • Long, low, bigger skull
  • Prominent nose with developed nasal chambers for cold-air protection 
This is a new and as yet inexact subbranch of genomic science. As more people have been tested the European average has inched up from the 2.6% figure that was used when I was first tested at 23andMe to the 2.7% figure now used. 

Even my Neanderthal component in my DNA is calculated differently by other labs. The National Geographic Geno 2.0 project reports Denisovan components as well as Neanderthal. This leads to a slightly different Neanderthal component result than above.

When our ancestors first migrated out of Africa around 60,000 years ago, they were not alone. At that time, at least two other species of hominid cousins walked the Eurasian landmass: Neanderthals and Denisovans. Most non-Africans are about 2% Neanderthal. The Denisovan component of your Geno 2.0 results is more experimental, as we are still working to determine the best way to assess the percentage Denisovan ancestry you carry. The evolution of this data is another way you are actively involved in helping advance knowledge of anthropological genetics!

So what does this mean? For now it is mainly a curiosity. As this branch of inquiry matures, it may mean much more -- or not. Our knowledge base of Neanderthal is small and our knowledge base of Denisovan DNA (found so far only in South East Asia) is currently minuscule.

23andMe offers this additional information on Neanderthals:

More about Neanderthals

Neanderthals were a group of humans who lived in Europe and Western Asia. They are the closest evolutionary relatives of modern humans, but they went extinct about 30,000 years ago. The first Neanderthals arrived in Europe as early as 600,000 to 350,000 years ago. Neanderthals — Homo neanderthalensis — and modern humans — Homo sapiens — lived along side each other for thousands of years. Genetic evidence suggest that they interbred and although Neanderthals disappeared about 30,000 years ago, traces of their DNA — between 1 percent and 4 percent — are found in all modern humans outside of Africa. Apart from the curiosity of finding what percentage of a modern human's genome is Neanderthal, the information has great value for science. By comparing our DNA with Neanderthal DNA, scientists can detect the most recent evolutionary changes as we developed into fully modern humans. Read more about the science behind this tool.

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