Oldest Human Genome Reveals When Our Ancestors Mixed With Neanderthals 128
sciencehabit writes DNA recovered from a femur bone in Siberia belongs to a man who lived 45,000 years ago, according to a new study. His DNA was so well preserved that scientists were able to sequence his entire genome, making his the oldest complete modern human genome on record. Like present-day Europeans and Asians, the man has about 2% Neanderthal DNA. But his Neanderthal genes are clumped together in long strings, as opposed to chopped up into fragments, indicating that he lived not long after the two groups swapped genetic material. The man likely lived 7000 to 13,000 years after modern humans and Neanderthals mated, dating the mixing to 52,000 to 58,000 years ago, the researchers conclude. That's a much smaller window than the previous best estimate of 37,000 to 86,000 years ago.
Yeah but ... (Score:5, Informative)
Re:Yeah but ... (Score:5, Insightful)
Re: (Score:3, Funny)
Re: (Score:2)
This is a general problem with the way people infer origin dates from sparsely sampled distributions: http://www.tjradcliffe.com/?p=... [tjradcliffe.com]
The earliest anatomically modern human fossils date from about 195,000 years ago, and people often say on this basis that anatomically modern humans appeared about 200,000 years ago, which is statistically illiterate at best.
Maybe people in the field know better, but I've seen an awful lot of claims like this and even in the semi-professional literature there seems to be a s
Neanderthals are 'modern' humans (Score:4, Insightful)
We've got to stop with the Neanderthal nonsense...
Neanderthals are *not* the magical missing link, nor does proving/disproving the existence of God or the truth of the theory of Evolution...none of this is in play
This is about legacy academia and how century-old academia wars are burdening good research today.
Another example: Clovis Culture http://www.examiner.com/articl... [examiner.com]
Clovis Culture theory has been the bane of anthropologists and archaeologists for decades...the only reason it was so entrenched is b/c of flaws in academia.
Neanderthals are the same. The whole notion of "Neanderthals" being a separate thing is just a miscategorization of traits that modern humans have. Maybe they are rare, and have become less attractive over the millenia, but not any different than any other trait.
Look at Russian boxer Nikolai Valuev [google.com]
The traits we collectively call "Neanderthal" are a distinction without a difference.
It's a failure of science that some ideas are irrationally difficult to disprove. Usually it is because people are using the research wrongly to prove a non-science point.
Again...Neanderthals can be variations on modern humans and it **does not disprove evolution!!!**
Yes, we are descended from Durc! (Score:2)
We've got to stop with the Neanderthal nonsense...
Right we do. There are just a few pieces of evidence now, but it may be that Neanderthal is actually a distant race that falls within our human specie. If their whole genome diverged from the branch of modern humans ~600,000YA and yet --- if there is additional evidence of interbreeding up to ~50,000YA, and humans from ~50,000YA could interbreed with us today (which I believe is true) --- then I consider it extremely likely that a Neanderthal could breed with a modern human.
And give your children superpow
clan of the cave bear (Score:2)
I checked it out...seems interesting
I kind of wish we could just ditch "neanderthal" and "cro-magnon" from the lexicon entirely...Cro-Mags are "AMH" and IMHO all the evidence shows that Neanderthals are AMH as well...so let's start from scratch with the genomic comparisons and make a new nomenclature
Back to Earth's Children....from reading the wikipedia, it seems like it might be similar to the film "Clan of the Cave Bear"
clan of the cave bear (Score:2)
That's the first book in the series.
It was made into a film 6 years after the original book, after she had written the second and third books.
i had already (Score:2)
whoa!
mind=blown
Re: (Score:2)
Jean Auel's work is literate smut. It's just a Stone Age bodice-ripper. Don't make me quote-mine for proof.
Calling it a 'bodice ripper' is obscene.
Earth's Children series comprises six books, ~1.8 million words altogether.
In Clan of the Cave Bear There is brutal sex without consent. It occurs within the context of a culture that does not require a woman's consent, which is how Auel chose to portray the Neanderthals --- yet it is clear that among the clan brutality is not tolerated. This is essential to the story... and a series of encounters between Jondalar and Ayla appearing throughout the books that are as
Re: (Score:2)
Neanderthals are the same. The whole notion of "Neanderthals" being a separate thing is just a miscategorization of traits that modern humans have. Maybe they are rare, and have become less attractive over the millenia, but not any different than any other trait.
Look at Russian boxer Nikolai Valuev [google.com]
The traits we collectively call "Neanderthal" are a distinction without a difference.
If you were complaining about the "Cro Magnon" concept you would be on solid ground. That turned out to be an imaginary construct. Neanderthals and Denisovans though definitely form a genetically defined group much more divergent from modern human populations than are found between the most divergent populations among modern humans (defined roughly by the San on one hand and everyone who is not African on the other). That said there is only 0.3% variation across the entire Neanderthal-Denisovan-Modern Human
Re: (Score:3)
Re: (Score:2)
What they are is an existence proof. And since there is crossover happening with every sperm or egg, this puts a limit on the probable number of generations...though I do need to include "probable".
P.S.: This wasn't a survey of the Y chromosome.
OTOH, since the amount was only about 2%, that indicates that the hybridization must have occurred several generations ago, perhaps 50.
(2% is the modern count, so you can't just say around 5 generations, as some of it is clearly being conserved).
OTOH, since we shar
Re: (Score:2)
Where's the sample?
In archaeology (and palaeontology in general), you play the hand you're dealt. (Though you can try to stack the deck a little by choosing where to dig.)
Can't be right (Score:1, Funny)
This can't be right. The world is only 2014 years old!
Re: Exinction (Score:3)
Re: Exinction (Score:2)
Re: (Score:1)
Drawing hard lines in the sand is perhaps not possible. Neanderthals would share a vast majority of our DNA just by being hominids. There are clusterings of genetic patterns, but a cluster is not a clear-cut distinction.
Re: (Score:2)
Exactly. Look at chimpanzee's that share about 99% of human's DNA. Neanderthals would have to be much closer.
Re: Exinction (Score:5, Insightful)
My guess is that the fact that no organisms exist with a Neanderthal genome defines them as extinct. Where one draws the line is more art than science I guess ... I know that there are some genetics in us (like the HMG group of proteins) that are ancient, but work so well that we still retain them. That doesn't mean the first species to have evolved them isn't extinct, it just means we evolved from them.
Well, I don't think that quite matches the scientific concept of "species". By your definition, almost all species who were alive 50,000 years ago would be considered extinct, but hardly any biologists would agree with that. It's true that no humans alive today have 100% Neanderthal genes, but it's also nearly certain that there are no living humans with 100% Cro-Magnon genes, either. What happened would be considered a mixing of several human sub-species after migrations of one or more African groups into Eurasia. The Cro-Magnon sub-species disappeared, too, and modern human Caucasian and Asian sub-species are the results of that mixing. This sort of thing happens in species all the time, when conditions allow such genetic mixing, and the result is rarely considered a new species.
The fact is that modern humans are all one species. We can and do interbreed when groups mingle, and there are no groups of modern humans that are genetically incompatible. If sub-species "disappear" by genetic mixing, that is usually not called an extinction event. It's just the routine and normal mingling of subspecies.
An interesting contrast is that most North American duck species are known to hybridize occasionally, and the offspring are usually fertile. Does this mean they're really all one species? No, because they all mingle a lot, but interbreeding is rare. They have "behavioral" species-separation features, mostly based on female mate choice. The females are mostly all mottled brown (protective coloring), and the males often approach females of other species (because they can't tell them apart either ;-). But the females usually only accept males that have the "right" color markings; the others are ugly to them. This suffices to keep the species separate, though there is probably a very low level of genetic interchange between many of the species.
But humans aren't like this. Even if we do generally prefer mates in our own subspecies, most of us do find many members of other subspecies physically attractive, and we'll mate with them given the opportunity. This means that we really are all the same species. We now have good evidence that the Neandertals were merely another subspecies, because when they had the opportunity, they did interbreed with those slender, dark-skinned folks who migrated into their territory. They did so often enough to produce a new subspecies that's physically distinct from either of the earlier two (or three or more).
Re: (Score:3)
Well, I don't think that quite matches the scientific concept of "species".
There is no generally-agreed-upon "scientific concept of species". The "Biological Species Concept" is a well-know and highly contentious artifact. It is clearly useful, but how it is defined varies enormously from person to person and across sub-fields.
This variation doesn't matter much in practice, but it gives philosophers who for some unfathomable reason want there to be just one BSC fits. They seem unaware that concepts are tools used by knowing subjects to understand objective reality, so different su
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
yet again, ring species.
Re: (Score:2, Interesting)
The Cro-Magnon sub-species disappeared, too, and modern human Caucasian and Asian sub-species are the results of that mixing.
Modern thinking suggests there was no Cro-Magnon subspecies, and that scientists of the time were actively looking for differences, hence ignored that the dimensions of the cro-magnon specimens were within the variation found within modern humans. Remember, prior to World War II, "racism" was more or less considered a branch of science. In Frank Herbert's Dune, there is an obsession with finding "humans" and separating them from "animals" by breeding, and while it's easy to rationalise that away as a Nazi r
Re: (Score:2)
. Note that the article also suggests that not all neanderthals were white, either. Note also that other traits often erroneously claimed to be neanderthal (blond hair, red hair, blue eyes) have again been shown not to be part of the neanderthal genome.
Re: (Score:2)
...
Just addressing the example given - the "Cro-Magnon" concept and term has been entirely abandoned by science. The problem was that there was never a definition of what a "Cro-Magnon" supposedly was. No distinguishing set of physical characteristics, no distinctive physical culture, and now with our powerful genetic analysis tools - no distinctive genetic pattern. Their range of variation is within that of modern humans, and supposing they were a subspecies would be as well founded as declaring "Samoans" a
Re: (Score:3)
What's a Neanderthal? What's a Cro Magnon?
Basically, these are names assigned to groups of fossils with similar bones. Sufficiently similar, for some nearly arbitrary value of sufficiently.
FWIW, it is my belief that they typical Neanderthal woman had a pelvic girdle to tight to pass a Cro Magnon baby. (The adults definitely had very differently shaped heads, though what that means is subject to doubt.) This explains nicely the lack of Neanderthal mitochondria in our genome. And it means that while Nean
Re: (Score:2)
So by what metric are Neanderthals extinct, if there are Neanderthals who have living descendants with a measurable amount of their genetic makeup?
There is no living population, large enough to produce additional generations of viable offspring, with a full, or substantial, Neanderthal genome.
Re: (Score:1)
This seems like circular logic. First one has to define what a "Neanderthal" is before answering that question.
Re: (Score:2)
This seems like circular logic. First one has to define what a "Neanderthal" is before answering that question.
Yep. A lot of taxonomy is like that.
In the process of classifying things they're trying to find or define sharp boundaries on a subject matter that is actually a continuum.
I recall, in my first encounters with the subject, trying to get a coherent definition of the distinctions between species, genus, family etc.. The instructor was utterly uanble to provide one. (Of course this WAS at the junio
Never fails... (Score:1)
Re: (Score:2, Informative)
Realize that 80% of the human population lives in abject poverty. The "trailer trash" are already above the average human condition.
One sample (Score:4, Insightful)
Re: (Score:2)
What you say makes no sense. If there were multiple mixings over large periods (we talk thousands of years) there would be uneven chopping of the DNA. Parts would be chopped more than other parts. Also if there were two mixings, but the two resulting groups never met, as your hypothesis assumes, than the second group that didn't result into modern humans is irrelevant. But good try at sounding smart. :)
Re: (Score:2)
Re: (Score:2)
But this would show either in the way neanderthal DNA fragments in the present day humans. If these fragmentations occurred at different times, the present day DNA would be fragmented differently in different present day samples. Since that is not the case, either it happened in one period or the second case never merged again with the current lines, rendering that irrelevant to present day humans.
Re: (Score:2)
Re: (Score:2)
I'm sure that in present populations DNA traced to Neanderthals has been split every which way. You get crossovers in (nearly) random places everytime a sperm or egg is made.
What's unusual here is that there haven't been many crossovers. This implies that the hybridization was recent.
My problem with this is that I'm not convinced that the populations were ever distinct enough that most genes could be traced to one species or another. So what they're saying is that 2% of our genes can be traced to Neander
Re: (Score:2)
That simply sounds like some journalist does not understand that there could be a world of difference between 1.7% and 1.9% for example and rounds both to 2%.
Re: (Score:2)
No, I don't think it's that simple. I think they're figuring the percentage against different baselines. Say the difference from chimpanzees was figured against the protein coding genes and the difference from Neanderthals was figured from a baseline of "common differences from chimpanzees". That would make it plausible. But there clearly isn't much time between the first different ancestor between humans and neanderthals, so a large difference is just implausible, even if we don't consider the evidence
Re: (Score:3)
Does not conclusively prove. Mixing could have occurred at many times and locations. While useful, more data needed.
Yup. But the fossil record tends to be rather sketchy, and has little concern for what we consider our "needs".
Re: (Score:2)
Title seems a bit racist (Score:5, Insightful)
The author's cro-mag bias is showing.
Her title implies that the neandertals in question are not also our ancestors.
A better title might have been "...genome reveals when our Cro-Magnon ancestors had sex with our Neandertal ancestors."
Re: (Score:2, Insightful)
I was wondering when the ugly racist interpretation was going to raise its head. So, far a long time Neanderthals were thought of as more primitive than humans, but now that it is known that most Europeans have Neanderthal DNA (and most Africans don't), they are being re-interpreted as being the origin of the master race.
Re: (Score:2, Insightful)
I... I think he was being satirical. People can't seriously consider having such a minor ancestral connection to a different sapient mammal along our evolutionary journey to actually have any significant effect on their modern existence, when put into perspective with all of the other influences (e.g. societal, economic, etc), can they?
You're being very optimistic there -- satirical comments are not usually made by anonymous cowards, and comments all in lower-case containing the "n" word are a bit of a staple on /., but they typically get modded down before you see them.
I actually once had a conversation with a guy who genuinely believed that Africa profited from colonialism, because despite all the war, slavery etc etc, the introduction of our "advantageous" neaderthal genes would benefit the continent in the long run....
Re: (Score:1)
The author's cro-mag bias is showing.
Her title implies that the neandertals in question are not also our ancestors.
A better title might have been "...genome reveals when our Cro-Magnon ancestors had sex with our Neandertal ancestors."
Yeah, I can't believe how many of my ancestors had sex with each other. Disgusting!
Question for sequencing expert. (Score:5, Interesting)
How accurate is it for the media to say a "complete" genome was sequenced? I know a little molecular biology and have been lead to believe that certain types of DNA, (centromeres, telomeres, other such regions with lots of repetitive sequences or "fragile sites") are very hard to sequence reliably. Are these "swept under the rug" in a "complete" sequence? Perhaps a related question, how are non-coding regulatory portions of chromosomes handled in whole genome analysis?
Re:Question for sequencing expert. (Score:4, Informative)
I don't know if ancient samples are processed differently, but for 'fresh' samples, the DNA gets broken up into small fragments (200-1000 base-pairs long), and then these fragments get sequenced. All bits of the genome have roughly even chance of getting sequenced, and with thousands or millions of copies of each fragment, you normally get reasonably even coverage over the whole genome.
The problem is when you map your sequences back onto a reference genome (ie the currently known chr1, chr2, chrX, etc). The aligning software will have trouble deciding where to place a fragment that is part of a highly repetitive sequence (like centromeres or telomeres) , or is duplicated several/many times (eg large gene families that have large sections of the genes in common, or pseudogenes that look like copies of other genes). In addition, we don't even know the exact sequence for some of these regions, so our reference human genome is contantly being updated (currently up to version 38).
For bioinformatics analysis, sometimes it is easier to sweep some of this under the rug. For example, some people use a reference genome that masks out the centromeres and telomeres (ie our reference sequence just has NNNNNNNNNNNN bases here, instead of As,Cs,Gs and Ts). Otherwise there are databases that list the regions containing repeated sequences or duplicated segments, so you can check any of your findings to make sure they aren't in a suspicious region.
Re: (Score:2)
I'd assume that the media is being quite "generous" in its interpretation. DNA tends to degrade fairly quickly, and I'd be really surprised if there was a good complete genome available to sequence. More probably several very long (unexpectedly long) sequences in several copies and nothing too corrupted.
I don't think the problems will be restricted to "fragile sites", and I'd bet the problems with telomeres weren't even considered, as those grow and shrink even during a normal lifetime.
If you're studying
Were pre-mixing humans really modern humans? (Score:2)
The summary refers to the time when neanderthals and modern humans intermixed, but can we really call what came before the mixing modern humans? It seems that something about the combination sparked huge evolutionary changes that allowed us to rather rapidly (evolutionarily speaking) develop modern society. As far as I'm concerned, the history of modern humans starts with the mixing.
Africans. (Score:3)
A little bit more upright, less stooped, a little bit less hairy, a little mound of forebrain in their foreheads.
There's a lot of genetic variation in Africa by comparison though. I'm thinking of those tall, really black-skinned, Sudanese looking people.
Re: (Score:2)
Probably you only wrote for the lulz, but I'm somewhat baffled. Obviously less hairy in Africa, due to climate
Not due to climate. Inuit aren't as hairier than Europeans, and Indians and Australian aboriginals can be very hairy.
But in parts of Africa, they have no arm hair at all [tumblr.com]. Not even the vestigial stuff. I think we'd gone further from the common ancestor with chimps/bonobos before we mixed back with Neanderthals.
African lips are further from chimps than Europeans too.
But more upright posture? I see caucasians with a more upright posture than Africans.
Do you? I definitely see the Sudanese around here always straight as a die, no hint of a slouch.
It is the forehead that's baffling: caucasians generally have a tall, upright forehead, while africans often have a gentler elevation angle from the eyebrows up... Which is a neanderthal feature.
I have a flat forehead, it's smoothly curve
Re: (Score:2)
(Primitive means that it was inherited from a common ancestor.)
FWIW, the sloping forehead isn't a Neanderthal feature, but a primitive feature that was retained by the Neanderthals, and by some Cro Magnons.
Also, you will find more genetic variation among the humans of Africa than among the humans of all the rest of the world combined. By a factor of greater than 2. I'm sure that *some* of them are stupid in comparison to the rest of the world, but they've just got a wider standard deviation. And without
Re: (Score:2)
I'd noticed that too -- that there's a broader range of physical types among Africans than everyone else combined. And as I once put it, turn everyone the same shade of green, and the African faces will retain the most individuality.
52,000 to 58,000 years ago? (Score:4, Insightful)
Strangely enough, beer was invented 57,999 years ago.
Re: (Score:2)
9 month before that the excuse of beer goggles came up.
Another proof (Score:2)
I can tell the same by looking at some of my neighbors
Later than that (Score:2)
Judging by one of my coworkers I'd say it was still going on around sixty years ago.
Most Interesting Part of This (Score:2)
This much older modern human has the same fraction of Neanderthal DNA as modern humans today.
Think about it.
We haven't seen any ancient Modern Humans that have a different degree of Neanderthal ancestry.
When Modern Humans first bred with Neanderthals the offspring were 50/50. If these F1s bred with each other predominantly from then on you would end up with a new breeding population that was roughly 50/50 in heritage. If the F1s predominantly bred with Modern Humans, then the Neanderthan portion would be c
Neanderthals are 'Not Fully Extinct' (Score:1)
Re: (Score:2, Interesting)
Re: Bone a Neanderthal (Score:4, Informative)
it couldn't be measured if it weren't a distinct genotype. That says nothing about speciation, of course.
Re: (Score:3)
Re: (Score:2)
Re: (Score:1)
The original fossils were mixed with clearly human fossils, but were later determined to have a condition called rickets.
So, yeah, this one seems a little made up to me, and I don't blame the 58% of Americans who don't believe in evolution.
If all the species are related, why are there all these shenanigans?
Re: (Score:2)
Re: (Score:2)
Someday they'll figure out "Neanderthal" is a completely artificial distinction, like "White Aryan", and the scientific consensus will be that Neanderthals R Us.
If by "artificial distinction" you mean the classification of lifeforms into different groups based on physical and genetic characteristics, the boundaries of those classifications made by scientists, then you have a valid point. A species is generally understood as a population that can interbreed and produce viable offspring. Homo sapiens and homo neanderthalis obviously can do so, so they should be the same species. However, there is a valid argument for them being classified a subspecies, due to measura
Re: (Score:2)
A species is generally understood as a population that can interbreed and produce viable offspring. Homo sapiens and homo neanderthalis obviously can do so, so they should be the same species.
That's a very poor understanding of speciation.
For example, consider ring species: species A & B can breed and species B & C can breed, but species A & C cannot.
Re: (Score:2)
For example, consider ring species: species A & B can breed and species B & C can breed, but species A & C cannot.
Good point. What if Neanderthals could create viable offspring with Homo Erectus but modern humans couldn't?
Life is messy.
Re: (Score:1)
It turns out that pretty much all biological processes are disgusting. Some people can't cope with this and become reclusive germophobic stuck-ups. Other people accept reality and find ways to be happy about it.
Incidentally, yours was not the first post, and the fact that you gave your post a title suggesting that you cared about getting first post tells a great deal about your maturity level. Not that it matters, you will get modded troll and your post will be read by hardly anybody.
Hi. Not sure wtf you're talking about, but I, for one, find beastiality repugnant. Apparently, you don't.
The post title was referring to the first cross-species orgy. But if your display of your ability to comprehend is any indication, you never had a chance of seeing that.
I thank the mods for correctly determining that I was trolling neanderthals and those that practice beastiality... and I'd do it again, proudly. Mod on, bitches.
Re: (Score:2)
There's no such thing as beastiality.
Indeed. [wikipedia.org]
Re: (Score:3, Funny)
I belong to the group having two to four percent Neanderthal in me and I still haven't scored with a pure blooded homo sapiens, you insensitive clod!