How Ancient DNA Is Changing Genetics and Consumer Testing Results

We began to grapple with the image of Neanderthals after their genome was sequenced in 2010. Were they unrelated brutes or more like rock stars?

“The thing that just comes clear from ancient DNA is that the people who lived in any one place a thousand years ago and 5000 years ago are almost never directly ancestral to the people who live in that place today.” So says David Reich, a pioneer in ancient DNA at Harvard and subject of an important video interview earlier this year from the Templeton Foundation. He says scientists have been fundamentally wrong about the origins of human beings and evolution. Before the lower cost and feasibility of ancient DNA studies in 2010, the hypothesis of a straightforward family tree of man or of any population group was,” he says, “to a large extent based on the idea that people spread in a simple way, moving from one place to the other out of an origin in Africa, maybe 50 or 60 or 70,000 years ago, spread to different parts of Eurasia and eventually to Australia and to the Americas. Once people got to a place, people pretty much stayed there without much change afterward.”

Instead of the tidy homelands and exact percentages direct-to-consumer companies typically hand us, says Reich, “The world is full of history that we didn’t know before.” Reich’s team, since working with anthropologist David Anthony, an expert on Central Asian ancestry and the horse and the wheel, has completely revolutionized our understanding of what it means to be British, or European, or any other standard nationality.  Yamnaya invaders on horseback and moving in wagons beginning about 3000 BCE pretty much replaced the entire population of Europe in a “disruptive” event that brought transformative change.

“The previous population is almost gone. It’s displaced by people with ancestry from the East. It’s a huge genetic impact,” says Reich. Such radical shifts in admixture proportions (and all populations, most particularly ancient ones, are mixed) constitute “the kind of surprise this field yields…it forces a new way of talking and discussing and thinking about these events in the past.”

Since the introduction of the DNA Fingerprint forensic method of ancestry analysis 20 years ago, shortly after the advent of ancient DNA studies , DNA Consultants has differed from most testing companies in refusing to estimate percentages of Irish, German, South Asian, sub-Saharan African etc. One of our customer’s list of top world populations can have hundreds of deep ancestral matches, from Euchee Indians to Taiwan Aboriginals. We tell customers no one is pure, and no population is pure. Everyone is mixed, and even ancient populations were mixed, in wave after wave of foreigners.

The genes inherited by the British people from Cheddar Man, a well known early English fossil, is probably 1%, says Reich. The other 99% of their national genome comes from many other sources.

If you want to ask, am I descended from Cheddar Man, the sort of individual who was excavated in Cheddar Gorge, where cheddar cheese is made, and we have their DNA and their DNA corresponds to someone who you could genetically predict had very, very dark skin, almost like what you would expect from Nigeria or something like this. Blue eyes, like a combination that’s very rare today. How much DNA do people in Great Britain have from this person? No more than 1% because of what happened, 6000 years ago.

Several replacement or near-extinction events and “profound disruptions” have occurred since Cheddar Man. It’s as though our theories about the past have suddenly been altered from widespread long-term uniformitarianism and complacency to an all-conquering catastrophism and ongoing, constant change.

On top of all the surprises, evolution itself is changing. Though “a lot of the genetic literature has suggested that evolution has been relatively quiescent over a longer time scale of hundreds of thousands of years. It seems like we’ve entered a period of rapid adaptation in response to profound, lifestyle changes.” The increasingly shocking discoveries of ancient DNA mean the smallest amount of admixture (say, a persistent signal of Polynesian in contemporary American Indians) is worth investigating, worth knowing about. The Big Picture percentages and circa 1500 world map of DNA companies gloss over a lot.

In sum, says Reich: “Ancient DNA has disrupted a number of assumptions about who we are.” It has been “revolutionary in terms of our origins.” Its study is important beyond its medical implications and social resonance. It’s an exciting tool of human knowledge—really an art—which we can justly pursue for its own sake, for the beauty and satisfaction of the answers it suggests. If you aren’t on board with the new wonders, please continue to browse our pages at DNA Consultants. You will be won over to the new views that ancient DNA has made possible.

More information

Your ancestors aren’t who you think they are | David Reich: Full Interview April 21, 2026

Transcription

Population Finder at DNA Consultants