Five surprising things DNA has revealed about our ancestors

February 16, 2018 by George Busby, The Conversation
Cheddar man. Credit: Channel 4

Researchers recently used DNA from the 10,000-year-old "Cheddar Man", one of Britain's oldest skeletons, to unveil what the first inhabitants of what now is Britain actually looked like. But this isn't the first time DNA from old skeletons has provided intriguing findings about our ancestors. Rapid advances in genetic sequencing over the past few decades have opened up a whole new window into the past.

1. Our ancestors had sex with Neanderthals

Archaeologists have known for some time that modern humans and Neanderthals lived together in Europe and Asia, but until recently the nature of their cohabitation was unknown.

In fact, after the first full Neanderthal mitochondrial genome (DNA located in the cell's mitochondria) was sequenced in 2008, there was still uncertainty among both archaeologists and geneticists as to whether humans interbred with our closest relative.

When the full genome of a Neanderthal was sequenced in 2010, comparisons with modern human DNA showed that all non-African people have pieces of Neanderthal DNA in their genomes. This could have occurred if humans and Neanderthal had interbred around just 50,000 years ago, a result that was confirmed a few years later.

2. Interbreeding enabled Tibetans to live in mountains

Amazingly, it wasn't just trysts with Neanderthals that kept our ancestors busy. When DNA was sequenced from a fossilised finger from a cave in the Altai mountains of Siberia, which was thought to be Neanderthal, showed that it was actually a new species of human, distinct from but closely related to Neanderthals. Analysis of its full genome showed that these "Denisovans" also had sex with our ancestors.

Five surprising things DNA has revealed about our ancestors
The look of love. Human and Neanderthal skulls. Credit: DrMikeBaxter/wikimedia, CC BY-SA

Tibetans, who live among some of the highest mountains in the world, are able to survive at altitudes where most people are encumbered by the lack of oxygen. Genetic analysis has shown that Tibetans, along with Ethiopian and Andean mountain dwellers, have special that allow them to process oxygen in this rarefied mountain air.

We now know that these genetic adaptations to altitude in Tibetans – they have a specific variant of a gene called EPAS1—were in fact inherited through ancestral mating with Denisovans.

It turns out that improvements in immunity, metabolism and diet among are also due to beneficial genetic variants inherited through this interbreeding with both Neanderthals and Denisovans.

3. Our ancestors evolved surprisingly quickly

Interbreeding accounts only for a tiny amount of human adaptation around the world. Analyses of DNA are showing us that, as our ancestors moved around the world, they evolved to different environments and diets far more quickly than was originally thought.

For example, the textbook example of a human adaptation is the evolution of lactose tolerance. The ability to digest milk past the age of three is not universal – and was previously assumed to have spread into Europe with agriculture from the Middle East starting some 10,000 years ago.

But when we look at the DNA of people over the past 10,000 years, this adaptation – which is now commonplace in northern Europe – was not present until around around 4,000 years ago, and even then it was still quite rare. This means that the spread of lactose tolerance across Europe must have occurred incredibly quickly.

Cheddar man skeleton. Credit: Channel 4
4. The first British people were black

DNA from one of Britain's fist people, Cheddar Man, shows that he was very likely to have dark brown and blue eyes. And, despite his eponym, we also know from his DNA that he couldn't digest milk.

While it's fascinating, and perhaps surprising, to learn that some of the first people to inhabit the island that is now known as Britain had dark skin and blue eyes, this striking combination is not altogether unpredictable given what we've learnt about Paleolithic Europe from ancient DNA. Dark skin was actually quite common in hunter gatherers such as Cheddar Man who were living in Europe in the millenia after he was alive – and have been around since the Ice Age.

5. Immigrants from the East brought white skin to Europe

So, if dark skin was common in Europe 10,000 years ago, how did Europeans get their white skin? There are no hunter gatherers left in Europe, and very few remaining around the world. Agriculture has replaced hunting as a way of life, and in Europe we know that farming spread from the Middle East. Genetics has taught us that this change also involved significant movement of people.

We also now know that there was also a large influx of people from the Russian and Ukrainian Steppe around 5,000 years ago. As well as DNA, the Yamnaya people brought domesticated horses and the wheel into Europe – and maybe even proto-Indo-European, the language from which almost all modern European languages originate.

A good bet for where white skin came from is that is was introduced by either the Yamnaya or Middle Eastern immigrant groups. It will have then become ubiquitous as a result of its benefit as an adaptation to low levels of sunlight – light skin pigmentation is thought to help people better absorb sunlight and synthesise vitamin D from it.

Explore further: DNA shows first modern Briton had dark skin, blue eyes

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Gigel
not rated yet Feb 16, 2018
Maybe black skin in Europeans was not just an inherited characteristic, but an adaptation to hunting at dawn and dusk. Maybe Neanderthals were black too. In herding it would no longer be relevant and was lost for better vitamin D production.

Now I wonder how those people were getting vitamin D with a black skin. They were either not in much need of it and probably getting enough of it from the Sun, or were getting it from another source, like hunting or fishing. But then, how were furry animals they were hunting getting enough vitamin D?

My guess is they were fishing a lot.
rrwillsj
1 / 5 (1) Feb 16, 2018
G, to date there is no DNA evidence to support that the skin color of the Neanderthals was dark.

Your speculation about fishing is probably correct for supplying nutrients scarce in a diet of game meat.

However, you are missing that the women in all known hunter-gather societies, generally supply about 80% of the calories consumed.

For all the weapons-fetish cultism you see in popular knowledge of proto-technological societies. The very best weapons were long-ranging physical endurance striding pace and clever use of fire to direct game movements.

Another possible source of nutrients from herbivore carcasses are the stomachs. The woman probably did a lot of the butchering. And would supply a means to cook the stomach intact. Hot rocks into water-tight baskets or pottery could cook the stomachs enough to be edible. Yet retain a lot of the nutrients of the herbage consumed by the animal.

Gigel
not rated yet Feb 16, 2018
I don't think grasses herbivores normally eat are edible for humans. Some may be even poisonous. Besides, there is not much vitamin D in plants (otherwise we would all be black probably and eat our vegetables).
TrollBane
not rated yet Feb 16, 2018
Dark skin would have had a protective benefit in most climates, but would have been outweighed by the benefit of greater vitamin D production in northern areas where exposed skin would often be minimal, especially where fishing was harder to do. Also keep in mind that dark skin doesn't completely stop vitamin D production.
rrwillsj
1 / 5 (1) Feb 17, 2018
G, herbage (not just grasses) being processed through ruminant digestive systems to release the nutrients. And herbivores have to be able to if not neutralize, at least minimize toxins.

Think, Haggis... Yummy!

"Use it up. Wear it out. Make it do or do without!"

Humans, Homo Anthropophagus, are omnivores. Meat is nice but when you had to chase it down? It was not very cooperative about filling your empty belly. So, everything was on the menu. Whatever you could get.

"If necessity is the mother of invention? Then desperation is the evil step-mother of scavenging."
TheGhostofOtto1923
5 / 5 (1) Feb 17, 2018
Hey willis
G, to date there is no DNA evidence to support that the skin color of the Neanderthals was dark
"An earlier analysis of ancient DNA in 40,000 and 50,000-year-old Neanderthal bones, respectively from Spain and Italy, suggested that our extinct cousins had light-coloured skin and reddish hair in their European heartland..."

"In [the middle east], Neanderthals may have had darker skins, explaining why our species did not gain a pale skin after interbreeding with them. Indeed, a study earlier this year of ancient DNA suggested that Neanderthals living in what is now Croatia had dark skin and brown hair.

"Neanderthal skin colour was probably variable, as might be expected for a large population spread out over a large territorial expanse," says Harvati."

-Dont you know that making shit up only makes you look more ignorant, not less?

BEWARE this moron.
a_whitefree_europe
1 / 5 (4) Feb 17, 2018
It would be great to see someone go around Europe with all these recent genetic studies from the past 4 years and go ask the general public what all this hatred and resentment toward the incoming settlers is about when the current "Europeans" are not the first people there and have no relation at all to those first people.
jonesdave
2 / 5 (4) Feb 17, 2018
.....when the current "Europeans" are not the first people there and have no relation at all to those first people.


Wrong. As already pointed out previously.
a_whitefree_europe
1 / 5 (2) Feb 17, 2018
https://www.natur...ure17993

"there is no evidence of the earliest modern humans in Europe contributing to the genetic composition of present-day Europeans".

There's also another report that came fairly recently that says the same thing. You can find by googling "insights into modern human prehistory using ancient genomes".
jonesdave
1 / 5 (2) Feb 17, 2018
https://www.nature.com/articles/nature17993

"there is no evidence of the earliest modern humans in Europe contributing to the genetic composition of present-day Europeans".

There's also another report that came fairly recently that says the same thing. You can find by googling "insights into modern human prehistory using ancient genomes".


And your point is? Who were they related to? Where are their haplotypes found now? Africa? Nope. Modern Europeans can be traced back to 37 000 years ago. That is not to say that related populations dating further back than that weren't here - just that they haven't been found and/ or have no viable DNA to test.
Stevepidge
1 / 5 (6) Feb 17, 2018
Modern DNA tests cannot even predict my eye color. This is not science, just political clap trap.
a_whitefree_europe
1 / 5 (2) Feb 17, 2018
As mentioned before I'm just applying the same "reasoning" that many a 'white' themselves have been using against the various non-'white' polulations around the world for decades now. Are you honestly not familiar with it?

Google "cbc solutrean", read the comments from the articles that came out last month and you'll see what I mean about the 'importance' 'whites' place on being "the first" people in some part of the world and the political implications it's supposed to have. Then after you've read the comments apply that same 'reasoning' to the people in Europe and you'll have a good laugh.

As for the rest of your comment, if for some reason the people in Europe today might have a small relation to some "Europeans" prior to 35,000 BC but not others then that would mean there was always multiple populations there and makes it pointless to complain about this imaginary migrant "crisis" today,
jonesdave
3.4 / 5 (5) Feb 17, 2018
Modern DNA tests cannot even predict my eye color. This is not science, just political clap trap.


Lol. Where did you get it done? The Max Planck Institute, or Ancestry? There is a difference you know, otherwise it would have cost you tens, possibly hundreds of thousands of dollars. And what is 'political' about DNA? Some people really should get an education before being allowed on the internet.
jonesdave
2.3 / 5 (3) Feb 17, 2018
As mentioned before I'm just applying the same "reasoning"........


Well, it isn't my reasoning. What some uneducated racist red necks believe is neither here nor there. Not to me. The fact that their ancestors were black is a hoot! Particularly as they may have been responsible for wiping out a bunch of perfectly decent white folk - i.e. the neanderthals. Irony, much!
nrauhauser
5 / 5 (1) Feb 17, 2018
The oldest Brit looks like the sort that English Defense League would spit on today. Mother Nature is not lacking in a sense of humor.
TheGhostofOtto1923
not rated yet Feb 18, 2018
More mothers of invention.
Modern DNA tests cannot even predict my eye color. This is not science, just political clap trap
"The group around Manfred Kayser of the Erasmus University Medical Center Rotterdam showed that it can be predicted with an accuracy of over 90% whether a person has blue or brown eyes by analysing DNA from only 6 different positions of the genome."
Stevepidge
1 / 5 (3) Feb 18, 2018
Modern DNA tests cannot even predict my eye color. This is not science, just political clap trap.


Lol. Where did you get it done? The Max Planck Institute, or Ancestry? There is a difference you know, otherwise it would have cost you tens, possibly hundreds of thousands of dollars. And what is 'political' about DNA? Some people really should get an education before being allowed on the internet.


Everything is political you ignorant bellend. The sheer fact that you can't understand that fact is telling of the monumental lack of observational intelligence that you possess.
Stevepidge
1 / 5 (3) Feb 18, 2018
Why don't they release the raw DNA. They won't. "Chedda" man wasn't even the oldest remains in the same cave system. 10,000 yr old DNA.. I have a feeling this DNA is "reconstructed". But nah, we wuz kangz!!! Africa was ours anyways and anti-colonial bias is unfounded.
Stevepidge
1 / 5 (2) Feb 18, 2018
Lets see what "Dr." Tom said about the DNA of Chedda man.

'We had a lot of genetic data but you have to kind of know what you're looking for,' says Tom. 'I had taken a recreational DNA test that looked specifically at physical traits, and they had helpfully listed the markers they use to come up with their assessments.'

'We were able to send that list of markers to our own bioinformatics lab to help us develop a portrait of Cheddar Man.'

Oh well isn't that interesting.
Stevepidge
1 / 5 (2) Feb 18, 2018
Frankly; until I see the actual results of the 36 SNPs assay of which they do not have 36 SNPs(they only sequenced 33 SNPs and many of them are not in the Assay); what they did was very fishy. Instead of using a tool that can be verified by a third party they used some obscure source than no other person can verify. Nonetheless Cheddar Man was derived for markers in the IRF4 gene which to this days appears to have a greater frequency in Irish people compared to other Northern Europeans and also had a mutation in the MC1R gene which contributes to red hair. That's what the data that they released shows. Also I should mention that having the ancestral variant at the SLC45A2 and SLC24A5 genes does not contribute to dark pigmentation namely because those two mutations explain about 30% of the variation observed between the darkest and lightest skin tones. In laymen terminology that means you can be ancestral for those two and yet have a skin tone that is 70% lighter than the
Stevepidge
1 / 5 (2) Feb 18, 2018
continued ... than the darkest skin tones and 30% darker than the lightest skin tone.
Show less
REPLY
a_whitefree_europe
1 / 5 (1) Feb 18, 2018
Well "they" apparently just released the paper there stevey boy: https://www.biorx...8/267443

Here's the method they apparently used too: https://www.ncbi....28500464
Stevepidge
1 / 5 (2) Feb 18, 2018
Well "they" apparently just released the paper there stevey boy: https://www.biorx...8/267443


Umm no.

A whitefree europe?? LOL. Good luck with your mud huts.
a_whitefree_europe
1 / 5 (2) Feb 18, 2018
That is apparently the paper, did you not scroll down just a little bit to the "re-tweets" where geneticists and journalists have "tweeted" that it is indeed the paper?

And do you not know what a 'white' is? That's why I keep putting quotes around 'white'. All a 'white' is a present day "European" who has no relation to the first people there and who is a quasi-descendant of people that originally had dark skin and only have 'white skin' now because they "lost" the migration 'war' to the Middle East around 10,000 years ago. That's genuinely what happened, all the genetic papers over the past 4 years all say the same thing.

As for your 'mudhut' comment, look up where agriculture originates around the world. Note how metallurgy, the wheel, etc, all come into existence after it and apply your comment to the "Europeans". Where would they be today without Middle Eastern agriculture?
Stevepidge
1 / 5 (2) Feb 19, 2018
That is apparently the paper, did you not scroll down just a little bit to the "re-tweets" where geneticists and journalists have "tweeted" that it is indeed the paper?

And do you not know what a 'white' is? That's why I keep putting quotes around 'white'. All a 'white' is a present day "European" who has no relation to the first people there and who is a quasi-descendant of people that originally had dark skin and only have 'white skin' now because they "lost" the migration 'war' to the Middle East around 10,000 years ago. That's genuinely what happened, all the genetic papers over the past 4 years all say the same thing.

As for your 'mudhut' comment, look up where agriculture originates around the world. Note how metallurgy, the wheel, etc, all come into existence after it and apply your comment to the "Europeans". Where would they be today without Middle Eastern agriculture?


Yep, that's a nice little story you have. Too bad it's 1000% conjecture and pure fantasy.
TheGhostofOtto1923
not rated yet Feb 19, 2018
look up where agriculture originates around the world
Agriculture was invented by people desperate to feed their families in grossly overcrowded regions. Grass is the last thing any self-respecting hunter gatherer would eat - too much effort, too little return.

But tropicals were forced to eat it because they had eaten everything else.

Meanwhile in the north humans were busy becoming a temperate species, living within their means in concert with their environment. Sadly they were repeatedly overrun by tropical refugees fleeing desperate overcrowding and related strife and violence in the south.

THEN, tropicals invented religions that actually maximized reproduction, for the purposes of outgrowing and overrunning.

This is why the middle east and the sahel are stripped, desertified, desolate.

This process has only gotten worse hasn't it? All of Eurabia will soon look like Mosul. Except that it will glow in the dark.

I like my story much better than the bigot's.
jonesdave
1 / 5 (1) Feb 19, 2018
Modern DNA tests cannot even predict my eye color. This is not science, just political clap trap.


Lol. Where did you get it done? The Max Planck Institute, or Ancestry? There is a difference you know, otherwise it would have cost you tens, possibly hundreds of thousands of dollars. And what is 'political' about DNA? Some people really should get an education before being allowed on the internet.


Everything is political you ignorant bellend. The sheer fact that you can't understand that fact is telling of the monumental lack of observational intelligence that you possess.


No, sh*t for brains. You have made a baseless, idiotic assertion which you cannot back up. Please, do tell us the political leanings of the people who performed the tests on Cheddar Man, or the remains from La Brana. Idiot.
a_whitefree_europe
1 / 5 (2) Feb 19, 2018
There's a video on youtube you should watch stevey boy. ('The') David Reich did a presentation late year in Israel about ancient genomics on a channel called "Taumod", "Tauvod", or something. About 20 minutes in he shows on various graphs and charts how the people of Europe and the people of the Middle East were two separate genetic 'clusters'. A little while later he shows that the ligjt skinned ME cluster assimilates the dark skinned "European" cluster around 9000 years ago but two populations actually start to "draw together" about 14,000 years ago for reasons not yet known. Believe me, I wouldn't be saying any of this if it wasn't true. Do yourself a favour and look it up, "David Reich ancient dna".

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