Genetic analysis of 40,000-year-old jawbone reveals early modern humans interbred with Neandertals

June 22, 2015, Howard Hughes Medical Institute
DNA taken from a 40,000-year-old modern human jawbone reveals that this man had a Neandertal ancestor as recently as four to six generations back. Credit: MPI f. Evolutionary Anthropology/ Paabo

In 2002, archaeologists discovered the jawbone of a human who lived in Europe about 40,000 years ago. Geneticists have now analyzed ancient DNA from that jawbone and learned that it belonged to a modern human whose recent ancestors included Neanderthals.

Neanderthals lived in Europe until about 35,000 years ago, disappearing at the same time modern humans were spreading across the continent. The new study, co-led by Howard Hughes Medical Institute (HHMI) investigator David Reich at Harvard Medical School and Svante Pääbo at the Max Planck Institute in Germany, provides the first genetic evidence that humans interbred with Neanderthals in Europe. The scientists reported their findings in the June 22, 2015, issue of the journal Nature.

"We know that before 45,000 years ago, the only humans in Europe were Neanderthals. After 35,000 years ago, the only humans in Europe were modern humans. This is a dramatic transition," Reich says. There is archaeological evidence that modern humans interacted with Neanderthals during the time that they both lived in Europe: Changes in tool making technology, burial rituals, and body decoration imply a cultural exchange between the groups. "But we have very few skeletons from this period," Reich points out.

So the jawbone that archaeologists uncovered in Romania in 2002, which radiocarbon dating determined was between 37,000 and 42,000 years old, was an important find. "It's an amazing bone," Reich says. The jawbone was found along with the skull of another individual in a cave called Pe?tera cu Oase. No artifacts were discovered nearby, so anthropologists had no cultural clues about who the individuals were or how they lived. The physical features of the jawbone were predominantly those of modern humans, but some Neanderthal traits were also apparent, and the anthropologists proposed that the bone might have belonged to someone descended from both groups.

For their analysis the researchers used 35 milligrams of bone powder from the jawbone. Credit: MPI f. Evolutionary Anthropology/ Paabo

Pääbo and Reich teamed up to investigate that possibility by analyzing DNA from the jawbone. Trace amounts of ancient DNA can be recovered from bones as old as the Oase jawbone, but to analyze it, that ancient DNA must be sifted out of an overwhelming amount of DNA from other organisms. When Qiaomei Fu, who was a graduate student in Pääbo's lab, obtained DNA from the bone, most of it was from microbes that lived in the soil where the bone was found. Of the fraction of a percent that was human DNA, most had been introduced by people who handled the bone after its discovery.

Using methods pioneered in Pääbo's lab, Fu enriched the proportion of human DNA in the sample, using genetic probes to retrieve pieces of DNA that spanned any of 3.7 million positions in the human genome that are considered useful in evaluating variation between human populations. Most of the DNA she ended up with was human, but came from people who had handled the jawbone since 2002, rather than the jawbone itself. Fu, who is now a postdoctoral researcher in Reich's group, solved that problem by restricting her analysis to DNA with a kind of damage that deteriorates the molecule over tens of thousands of years.

Once they had discarded the contaminating DNA, Reich's team could compare the fossil's genome to genetic data from other groups. Through a series of statistical analyses, a surprising conclusion emerged. "The sample is more closely related to Neanderthals than any other modern human we've ever looked at before," Reich says. "We estimate that six to nine percent of its genome is from Neanderthals. This is an unprecedented amount. Europeans and East Asians today have more like two percent."

That suggested the Oase individual's ancestry was recent. As DNA is passed on from generation to generation, segments are broken up and recombined, so that the DNA inherited from any one individual becomes interspersed with the DNA of other ancestors. Reich found segments of intact Neanderthal DNA in the fossil that were large enough to indicate that the Oase individual had a Neanderthal ancestor just four to six generations back. That suggests that modern humans interbred with Neanderthals after they had arrived in Europe.

"It's an incredibly unexpected thing," Reich says. "In the last few years, we've documented interbreeding between Neanderthals and modern humans, but we never thought we'd be so lucky to find someone so close to that event."

The Oase individual is not responsible for passing his Neanderthal ancestry on to present day humans, however. Reich found no evidence that he is closely related to later Europeans. "This sample, despite being in Romania, doesn't yet look like Europeans today," he says. "It is evidence of an initial modern human occupation of Europe that didn't give rise to the later population. There may have been a pioneering group of modern humans that got to Europe, but was later replaced by other groups."

Explore further: Dating encounters between modern humans and Neandertals

More information: An early modern human from Romania with a recent Neanderthal ancestor, Nature; 22 June, 2015. DOI: 10.1038/nature14558

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tadchem
1 / 5 (2) Jun 22, 2015
It is almost syllogistic that, since Neanderthals and 'moderns' had a common ancestor, for some time after the population divergence interbreeding would have been easy, and possibly likely, but with diminishing probability over time.
The question should now be whether or not interbreeding producing fertile offspring occurred or was even possible at the time the Neanderthals died out. If it was possible, then they would have to be considered a separate race of the same species - Homo sapiens.
jonesdave
3.7 / 5 (9) Jun 22, 2015
It is almost syllogistic that, since Neanderthals and 'moderns' had a common ancestor, for some time after the population divergence interbreeding would have been easy, and possibly likely, but with diminishing probability over time.
The question should now be whether or not interbreeding producing fertile offspring occurred or was even possible at the time the Neanderthals died out. If it was possible, then they would have to be considered a separate race of the same species - Homo sapiens.


Surely the offspring must have been fertile, otherwise this individual wouldn't have DNA from 4-6 generations previous?
Jeffhans1
5 / 5 (3) Jun 22, 2015
There would be no evidence of interbreeding if we weren't mutually fertile. There was a third species Denisovans that also left genetic footprints in humans:
http://www.livesc...ns.html.
The people of the Andes mountains and high altitude residents of tibet both have a large chunk from them that give a boost to living in low oxygen environments:
http://www.nature...408.html
Torbjorn_Larsson_OM
5 / 5 (1) Jun 23, 2015
"It is evidence of an initial modern human occupation of Europe that didn't give rise to the later population."

Poor Neanderthal, being so close and still doesn't make its genes into the modern population.

@tadchem: "If it was possible, then they would have to be considered a separate race of the same species - Homo sapiens."

Biologists could disagree. They look for genetic barriers, and the genetic evidence show sperm incompatibilities, lower fertility, in even the earliest introgression into the modern gene pool. So for them the evidence shows that these were different species (we and them), if not yet fully separated.

@Jeffhans1: It gets better. Some African studies show signs (if weak as of yet) of introgressions from similarly separate populations, and the large Spanish sample of Homo (which I can't remember the name for) show signs of one as reported 1-2 years back. It could even be H. erectus that introgressed into Neanderthals and then the found group.
JVK
1 / 5 (3) Jun 23, 2015
Re: "We know that before 45,000 years ago, the only humans in Europe were Neanderthals."

Serious scientists know that RNA-mediated amino acid substitutions link the epigenetic landscape to the physical landscape of DNA in all organized genomes of all genera.

See, for example: Nothing in Biology Makes Any Sense Except in the Light of Evolution http://img.signal...nsky.pdf "...the so-called alpha chains of hemoglobin have identical sequences of amino acids in man and the chimpanzee, but they differ in a single amino acid (out of 141) in the gorilla" (p. 127).

What this misrepresentation of biologically-based cause and effect shows us is that evolutionary theorists may continue to claim that they know what they do not know about how fixation of nutrient-dependent RNA-mediated amino acid substitutions differentiates cell types.
JVK
1 / 5 (3) Jun 23, 2015
Excerpt: "Using methods pioneered in Pääbo's lab, Fu enriched the proportion of human DNA in the sample, using genetic probes to retrieve pieces of DNA that spanned any of 3.7 million positions in the human genome that are considered useful in evaluating variation between human populations."

See also the reporting of RNA-mediated events by senior author, Pääbo: http://linkinghub...07620138

Primate populations are differentiated by RNA-mediated amino acid substitutions in the context of the physiology of their nutrient-dependent reproduction. All biodiversity is biophysically constrained by the same molecular mechanisms in all genera. Re-evolved flagella link the molecular mechanisms of ecological adaptation that occurs "over-the-weekend." http://www.the-sc...ewiring/

What links changes in one jaw to one skull in the context of "evolution?"
Captain Stumpy
5 / 5 (3) Jun 23, 2015

Primate populations are differentiated by RNA-mediated amino acid substitutions in the context of the physiology of their nutrient-dependent reproduction. All biodiversity is biophysically constrained by the same molecular mechanisms in all genera. Re-evolved flagella link the molecular mechanisms of ecological adaptation that occurs "over-the-weekend." http://www.the-sc...ewiring/
your link does NOT contain the quote you have attributed to it

just because you don't understand the biology doesn't mean it aint real or true
See Lenski et al, or Dr. Extavour et al etc
Noumenon
1 / 5 (4) Jun 24, 2015
just because you don't understand the biology doesn't mean it aint real or true

That is simply your own conjecture and is not supported by empirical evidence. Use the scientific method.
JVK
1 / 5 (3) Jun 24, 2015
http://www.the-sc...rprints/

Nutrient-dependent/pheromone-controlled adaptive evolution: a model. http://www.ncbi.n...24693353

Sniff tests used to create olfactory fingerprint http://medicalxpr...int.html

What these reports have in common is the link from RNA-mediated cell type differentiation to biodiversity that is biophysically constrained by the ability to find nutrients and to reproduce.

What these accurate representations do not have in common with ridiculous theories about mutations and evolution is that they are based on biological facts, not pseudoscientific nonsense.
JVK
1 / 5 (3) Jun 24, 2015
http://dx.doi.org....1002185
From Here to Eternity—The Theory and Practice of a Really Long Experiment

my comment to plos
The citation to "The Man Who Bottled Evolution" makes no sense now that serious scientists are "Combating Evolution to Fight Disease." http://www.scienc...88.short All that Lenski's work has ever shown is that ecological adaptation is nutrient-dependent and pheromone-controlled in species from microbes to man via RNA-mediated links between metabolic networks and genetic networks.
Captain Stumpy
5 / 5 (1) Jun 25, 2015
a model
@jk
debunked here
http://www.socioa...ew/24367

What ... ridiculous theories about mutations and evolution ...biological facts, not pseudoscientific nonsense
1- your model is debunked, so it is NOT accurate
2- your own model requires MUTATIONS, therefore you are wrong in your assessment above
3- your historical interpretations of science are 100% wrong to date (and as we can see above, this includes your own model)
4- evolution is based on evidence: you can't even prove human Pheromones exist yet

@Nou
that link good enough for you? if you are nice, maybe the author or another biologist will explain it to you
I suggest looking up here
http://freethough...s-place/

or are you being a creationist like jk now and trying to defend ALL the pseudoscience because of the similarities to your Philo talk?
Captain Stumpy
5 / 5 (1) Jun 25, 2015
All that Lenski's work has ever shown is that...
@jk
let me finish that for you
Lenski shows that MUTATIONS can be beneficial and that evolution theory is on strong ground...
& Lenski has debunked your claims in the past regarding your interpretations of his work, just like Dr.'s Extavour and Whittaker have as well... including specifically reading your posts here on PO and trying to ascertain what your word-salad garbage techno-talk actually means (most real biologists ignore you as a crackpot)

Also: just because you can TROLL on ScienceMagazine doesn't mean you are posting legitimate science... you don't get replies from scientists because you don't unsderstand the science (that is why most of them ignore you - you can't teach an old mensa dog new tricks, apparently)

for my new GROUPIE TROLL Nou's benefit: see also
http://beacon-center.org/

http://myxo.css.m...dex.html

keep following me around, you might learn something nou!
Noumenon
1 / 5 (3) Jun 25, 2015
just because you don't understand the biology doesn't mean it aint real or true

That is simply your own conjecture and is not supported by empirical evidence. Use the scientific method.

.... are you being a creationist like jk now and trying to defend ALL the pseudoscience because of the similarities to your Philo talk?

That is simply your own conjecture and is not supported by empirical evidence

What philo talk? You're not specific enough to even refute. Please use the scientific method.

I don't even read JVK posts because I don't know enough about the subject to disentangle his word salad [as it appears to me],.... and whether he is a creationist crank or not,... he appears certainly to know more about the subject than I do, and since I respect science enough that to defeat his arguments by more than proxy, I would need to know the nuts and bolts of the topic at hand,... thus I do not engage,... despite rejecting creationism or even a god.
JVK
1 / 5 (2) Jun 25, 2015
Lenski shows that MUTATIONS can be beneficial and that evolution theory is on strong ground...


Mutations perturb protein folding, which is why only the fixation of amino acid substitutions that stabilize the organized genomes of all genera has been linked from the epigenetic landscape to the physical landscape of DNA via metabolic networks and genetic networks in the context of their nutrient-dependent RNA-mediated physiology of reproduction.

In species from E. coli to humans, the physiology of reproduction is nutrient-dependent and pheromone-controlled. That means the only thing Lenski has ever shown is that E. coli are genetically predisposed to ecologically adapt when the availability of nutrients changes.

That's what I showed with examples from other species, and the examples refute ridiculous theories about mutations and evolution.

http://www.ncbi.n...24693353
Captain Stumpy
5 / 5 (1) Jun 26, 2015
Mutations perturb protein folding
@jk
this is proven to be false not only by Lenski et al, but by quite a few other people as well
http://myxo.css.m...dex.html

your own model requires mutations to work, per your own words (shall i post them again?)

your comments re: the above have also been specifically refuted as well, from Dr.'s Extavour to Whittaker and many others. your conclusions re: mutations are based upon a creationist/7th day adventist dogma which is not science
https://en.wikipe...Arkansas

http://www.ncbi.n...24693353
your model is debunked and proven false
http://www.socioa...ew/24367

@Nou
it is not conjecture: your own posts are continually proving my point (which is the empirical evidence you seek)
and whether he is a creationist crank or not
he's already said he is a creationist and posted links to creationist sites

Keep trolling!
JVK
1 / 5 (2) Jun 26, 2015
The microbiome: stress, health and disease
http://link.sprin...3-9488-5

Why aren't we discussing nutrient stress and/or social stress in the context of mutations and evolution? Does anyone else besides the biologically uninformed science idiot, Captain Stumpy, not realize the difference between a mutation and an amino acid substitution?

How could a mutation link metabolic networks to genetic networks in the context of health and biodiversity?
Captain Stumpy
5 / 5 (1) Jun 26, 2015
Does anyone else besides the biologically uninformed science idiot, Captain Stumpy, not realize the difference between a mutation and an amino acid substitution?
@jk

you tried this argument many times already and you've been debunked multiple times, including having it pointed out that you don't understand biology well enough to make your claims, from epigenetics to simple biological processes...

see: ALL post arguments between you and ANONYMOUS9001 as well as RealScience, TL O_M, AAP and Myers

still battinga 100% fail rate interpreting biology and science
Moebius
1 / 5 (1) Jun 28, 2015
"...modern humans interbred with Neandertals" and cows, horses, sheep, knotty trees, snakes, lizards.......
JVK
1 / 5 (2) Jun 28, 2015
Comparative Analysis of RNA Families Reveals Distinct Repertoires for Each Domain of Life
http://dx.doi.org....1002752

The oldest RNAs are primarily associated with protein synthesis and export.


If my model of RNA-mediated biologically based cause and effect did not link metabolic networks to genetic networks in all genera via their nutrient-dependent physiology of reproduction, Poole's group would not be desperately attempting to invent another theory of evolution.

See: http://www.canter...=4047206

With Prof. Jun Ogawa and team at Kyoto University, we are working to engineer E. coli that can produce DNA via an alternative pathway to the ubiquitous ribonucleotide reductase pathway, which all life uses to generate DNA building blocks from RNA. This work may tell us if DNA could have evolved via a simpler route than the complex reaction performed by ribonucleotide reductases.

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