The Neanderthal must have been really drunk...
One thing is clear, fertile interbreeding is the definition of species so we are the same species as Neanderthals, and we're both human.
Boffins in Germany have extracted the oldest human DNA yet discovered – from a 45,000-year-old thigh bone found in Siberia. And after studying the genetic goop, the researchers have concluded that humans started interbreeding with their Neanderthal cousins about 60,000 years ago. 45,000 year old human bone 'What a slut' A …
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The anthropologist Björn Kurtén hypothesized that the Neandertals were attracted to Cro-Magnons/Early Modern Humans because the details of the latter's physiology, such as lack of a heavy brow ridge, made them look like a Neandertal child. This brought out the Neandertals' mothering/nuturing instinct. Any offspring would be hybrids of the two species and have the benefit of hybrid vigour, which probably made them even more attractive, but the very unfortunate disadvantage of being sterile.
The C-M/EMH may have had to beat them off with a stick, but any kids would have been an evolutionary dead end.
The C-M/EMH may have had to beat them off with a stick, but any kids would have been an evolutionary dead end.The C-M/EMH may have had to beat them off with a stick, but any kids would have been an evolutionary dead end.
Excuse me for being thick, as I am posting this before my 3rd quadruple espresso this morning.
If it was an evolutionary dead-end then why the f*** (yes I meant to use the f*** word) does the white Caucasian and most of Asian population have 2.6 % Neandertal DNA? Did this happen as a result of the fairy dust form of genetic transfer?
Out of all theories the "Neandertal as first Garry Glitter" theory is frankly one of the most preposterous pieces of rubbish I have ever heard. If anything, it is the opposite, us modern humans being attracted to atavistic treats. We can stare into a fire for half an hour with our mind blank and I am just going to restrain myself from commenting on the effect that chest hair + muscles + 6 pack have on the prettier part of humanity.
"the Neandertals were attracted to Cro-Magnons/Early Modern Humans because the details of the latter's physiology, such as lack of a heavy brow ridge, made them look like a Neandertal child"
Detectives will be along shortly to seize assorted cave walls for evidence of making indecent psuedo-images of children.
Kurten passed away long before the sequencing of the Human Genome let alone the Neandertal variant. He was writing about the facts as he understood them (the sterile hybrid was the accepted theory) and threw in a bit of fantasy to explain the interbreeding and a possible reason for the subsequent extinction of the Neandertal line.
Being able to tell a story does not detract from his ability as an anthropologist, else we might also discount the work of Robert L Forward and Carl Sagan.
@lawndart, "Being able to tell a story does not detract from his ability as an anthropologist," That was exactly what my post was about. And I do appreciate him in both respects.
" Neandertals were attracted to Cro-Magnons/Early Modern Humans because the details of the latter's physiology, such as lack of a heavy brow ridge.....", That part is the fantasy part, and I would assume anybody understands that. (like did Björn Kurtén).
I can hypothesize that the Neandertals were attracted to Cro-Magnons/Early Modern Humans because they lacked the knowledge of how to produce alcohol. You know the way it went in the Americas later.
I find my story more fun and more possible.
One idea, thought, Björn had was that it would be fun if one could have ones fathers, say the last one thousand sitting, side by side, along a table. Then you could walk along and see what made you and you could pass a nice joke down the table and the son would pass it on to his father. Fun.
Now I had this dream one night.
It was splendid, the venue with the long table was by a nice lake. The sun was shining, birds singing, the white tablecloths where swaying slightly in the warm wind. There was lots of beer and wine, (the water was in the lake). There was plenty of food, beef and hamburgers, the odd pizza and fruit. Plenty.
There was hugging and kissing, laughter. Father and sons swimming in the lake together. I haven't seen you for a thousand years, dear father. What heaven did you go to, or hell perhaps, he he.
But in the morning, as I woke up with a hefty hangover. It was a complete mess, not a drop of medicine in sight, broken chairs, overturned tables, bloody table cloths, broken bottles, some hamburgers and a pizza in the process of drowning in the lake. My head hurt. Some fathers where lying in the damp grass trying to move. All the rest had gone.
Without trying to stick to any chronological order about what seemed to have happened, there was a father who met with the son who killed him. There was the father who looked at his son said "who the hell are you, a damned foreigner, I cannot understand a word, prick, where is my son. The reason for that problem was probably that the father was a good looking shoe salesman who traveled the world. There was a similar case with the mother who met a foreign army in the woods, not really her fault, of course. There was the father who looked at the son and said "what the hell, I have tried to forget about you for six hundred years, where are my good sons, who the hell has arranged this, computers, my arse. And there was this huge viking who stood up and declared, not my son not my father and went totally bärsärk. I was told he took off to walhalla in order to stay alive. On the other hand there was some happiness too, like the son who found out that the janitor was in fact his father, something he had wished for since a kid.
I have to stop here or you might not believe I belong to a well educated and clever family. Some things have to stay in Las Vegas, as they say. The joke, not good at all, missunderstod, lost in translation.
I have had to come to the conclusion that if you wish for something then think first. Pity Einstein did not write any stories.
If Neanderthal/Cro-Magnon hybrids were always sterile, where did that 2.3 percent Neanderthal DNA in a Cro-Magnon come from?
Depending on how closely the two species were related, the hybrids may have been sterile some of the time or most of the time, but I don't think scientists know to what extent that may be the case yet.
Re: Migrations out of Africa and the related 'Eve Hypothesis'.
Given roughly two children surviving to have grandchildren (etc.), and it has to be about two if you think about it, then only about 75% of one's unique genetic code is carried forward, and about 25% is not (from 50%^2). This the Maternal or Paternal Lineage Extinction Ratio (MLER, PLER). The impact is clearly visible in MtDNA and surnames, and it drives speciation. The entire 'Eve Hypothesis' (supposed population bottle-necking, etc.) requires not understanding this simple fact. Eves are inevitable and innumerable.
Google 'Inevitable Eve' for complete explanation.
Paleoanthropology is too often unthinking rubbish speculation.
One thing is clear, fertile interbreeding is the definition of species so we are the same species as Neanderthals, and we're both human.
I'm completely sympathetic to that view as applied to "human", but it's not a sufficient definition of species (which may need multiple definitions)
Consider the Ruddy Duck (USA) and the White-headed duck (Europe). They have very different plumage and have not interbred since the Atlantic ocean became wide enough to prevent these ducks from crosing it. That's maybe 50M years. So, they are recognised as two different species, because naturally they can't interbreed.
But when humans brought Ruddy ducks to Europe, female White-Headed ducks preferred to breed with Ruddy duck males! The hybrids are fertile. So they were once the same species, and no genetic speciation event occurred over the long separation. And if humans hadn't started on a Ruddy duck eradication programme in Europe, soon they'd have still been two distinguishable groups: one Ruddy, one Hybrid, and the European White-headed duck would be extinct.
Or consider the Herring and Black-Headed gulls. You find both in the UK and they don't interbreed. But travel East, and you'll find that the local herring gulls look slightly diffrent. Keep going, and by the time you arrive in the USA, they look a lot like Black-headed gulls. So one species, that's spread around the globe and is overlapping with itself in the UK. But were a catastrophe to wipe out the gulls everywhere except the UK, then two species? (because they won't naturally interbreed here, the complete opposite situation to the ducks).
Or consider the wallabies of Northern Australia, which are the "victims" of a virus which is causing them to undergo genetic mutation at an extremely high rate. There are about fifty species. We aren't quite sure because they all look much the same and inhabit the same evolutionary niche. (How the wallabies know which they are is an interesting question.) Whether there are fifty species with no overlap, or whether small subsets of them are still inter-fertile with other small subsets to an extent sufficient to link all into one or a lesser number of species at the present time, again, we don't know.
Yes, I got the wrong gull. Lesser Black-backed is the other end of the Herring gull "ring species". It's also rather more complex than the simple version I described. Details here
http://en.wikipedia.org/wiki/Ring_species
(As to size, if you think about the range of sizes that dogs come in ... thought experiment, stock an island with Yorkshire Terriers and Irish Wolfhounds but no other dogs, add appropriate prey species, when does one species of dog become two species? )
"stock an island with Yorkshire Terriers and Irish Wolfhounds but no other dogs, add appropriate prey species, when does one species of dog become two species?"
A friend made the mistake of assuming her large collie dog and small terrier bitch were incompatible by size. How they did it no one knows - but the litter were definitely a cross breed.
Sorry, but it seems to me that nothing you have said alters the fact that Neanderthals and more modern humans had fertile offspring and so were the same species, just as a dachsund and a pitt bull are the same species. If two ducks that could interbreed and have fertile offspring are for some reason regarded as different species then that is a taxonomy problem. I mean, if it walks like a duck and it quacks like a duck...
"A one night stand that founded a people that went to the motherfucking moon. I'd say it was pretty successful."
But for that drunken bit of hokey pokey we'd be on Mars now.
More seriously, I wonder if there were negative behavioural traits that are legacies of our "minority ancestor"?
As I understand it, the species name is Homo Sapiens, of which we are the sub-species Homo Sapiens Sapiens. The neanderthals were the sub-species Homo Sapiens Neanderthalis. Nothing problematic about different sub-species interbreeding - was probably good fun for those concerned :-)
It's not much remembered now, and certainly Pääbo himself don't talk about it any more, but his original claim to fame was that he in the 1980's "proved" that modern humans and neanderthals didn't interbreed. That study, published in Nature, is the sole reason Neanderthals were ever considered a separate species to begin with, rather than a geographical race of ordinary humans. It's also the basis for the "blitzkrieg" theory, that modern humans violently wiped out the Neanderthals.
Now, when it's known that Neanderthals interbred with modern humans, and didn't go extinct but instead merged with the new african immigrants, Pääbo is eating his cake and having it too: he still pretends that modern humans and Neanderthals were different species, AND he's publishing studies supporting that they interbred.
If we ignore Pääbo's early junk, the evidence suggests that the Neanderthals were a geographical race of Homo sapiens, which merged with more recent immigrants from Africa to form the current Europeans. Further east, the recent immigrants from Africa merged with other archaic races to produce the Asians, with the only remaining archaic non-african race being the aboriginals of Japan and Australia/New Guinea.
No blitzkrieg, no extinction, no speciation, just humans doing their thing like they always have.
Well, the two things are not completely exclusive. The definition of species as "can't interbreed" kinda breaks down a bit over very long time scales. When a species splits into two, it takes a very long time, during which things are not so clear. You can have some time during which two groups can interbreed, some time during which they can mate and usually produce fertile offspring, and some time during which they can mate and usually produce infertile offspring, before they get to the point where they definitely can't interbreed - and each of these stages can last hundreds of generations, and they may not even progress at the same rate across geographically distinct areas.
Sometimes, nature draws a sharp line very quickly.
There are virii that cause chromosomal abnormalities which result in offspring with one more or less chromosomes than their parents (the same genes, but repackaged).
If only one such mutant child existed at any time, it would never find a mate to create fertile progeny with. That's because any such offspring would have an odd number of chromosomes, and the process for creating another generation would require something-and-a-half chromosomes from each parent, which can't happen.
But an active retroviral plague creates many compatibly mutated offspring in a single generation, and if they are able to identify each other and continue to breed, that's a new species born -- with the sharpest of dividing lines between it and its parents, in a single generation.
This is happening today with Australian Wallabies. Me, I want to know how such a virus evolved!
"The definition of species as "can't interbreed" kinda breaks down a bit over very long time scales."
Pääbo's original article used mitochondrial DNA to prove that there never were any interbreeding between neanderthals and the recent african arrivals. That was the basis for considering them separate species. It was wrong. There is no ifs, buts or maybe's about it: the study was wrong, they did interbreed.
"That study, published in Nature, is the sole reason Neanderthals were ever considered a separate species to begin with, rather than a geographical race of ordinary humans."
Such ordinary humans that it was barely possible for homo sapiens sapiens (HSS) to crossbreed with them. There's evidence of high levels of hybrid male infertility and that many Neanderthal genes were purged from the hybrid genome in a couple dozen generations.
"It's also the basis for the "blitzkrieg" theory, that modern humans violently wiped out the Neanderthals."
No Neanderthal mitochondrial DNA has been found in our genome. If we got along well with Neanderthals, why didn't we bring Neanderthal girls home to meet mom and dad? Or is the issue that Neanderthals and HSS were sufficiently different species that Neanderthal women couldn't have hybrids?
@cray74... You're arguing that the hybrid males were mostly infertile, and we didn't interbreed with the Neanderthal girls; so, tell me, where did that small percentage of Neanderthal DNA come from?
On the other hand, if you remember i) that the estimate for the most recent common ancestor of all today's humans is only a few thousand years ago ii) there is no mixing of mitochondrial DNA, then you'll realise that we'll all have either Neanderthal mitochondrial DNA or we'll all have homo sapiens sapiens mitochondrial DNA, and, by chance, it's the second alternative.
Also, we're talking about small wandering groups occasionally meeting, so a small disaster, say an avalanche, could have wiped out an "interesting lineage" (meaning one that would overturn accepted theories and cause endless academic discussions today), without any need to invoke a "blitzkrieg" theory.
@Allan George Dyer: "You're arguing that the hybrid males were mostly infertile,"
I'm reporting that point, not arguing. I didn't do the original research on negative selection of Neanderthal DNA in homo sapiens sapiens and what it implies for male hybrid sterility, I'm quoting it after Googling it. And it seems Vociferous is about to prove my points wrong. :)
"and we didn't interbreed with the Neanderthal girls;"
I didn't say that. I reported that, to date, no trace of Neanderthal mitochondrial DNA has been found in modern human cells. There are multiple possible explanations for that, including bad DNA analysis.
"On the other hand, if you remember i) that the estimate for the most recent common ancestor of all today's humans is only a few thousand years ago ii) there is no mixing of mitochondrial DNA, then you'll realise that we'll all have either Neanderthal mitochondrial DNA or we'll all have homo sapiens sapiens mitochondrial DNA, and, by chance, it's the second alternative."
I agree with you to the point that, "there's no mixing of mitochondrial DNA," since it only comes down through the mother's line. However, you could very easily have both female Neanderthals and female humans giving birth to hybrids, and since the populations overlapped for tens of thousands of years the expectation is both combinations (male homo sapiens sapiens - female neanderthal, female homo sapiens sapiens - male neanderthal) seem likely to have been tried many times.
In other words, a point failure like an avalanche is unlikely to wipe out all hybrids descending from neanderthal females. There should be hybrids descended from neanderthal females, but they haven't been found yet by mitochondrial DNA evidence.
@cray74 - You did say, "why didn't we bring Neanderthal girls home to meet mom and dad?", which I took to be a way of saying "we didn't interbreed with the Neanderthal girls", was I wrong? What did you mean?
Yes, I was wrong about the mitochondrial DNA… I was confusing the date of MRCA (about 3000 years) and the matrilineal most recent common ancestor (mitochondrial Eve, about 100,000 years).
I'm not sure how the statistics play out… I wasn't suggesting that a single avalanche would destroy all Neanderthal mitochondrial DNA descendants in a single event, but that the total hominid population at the time was small, split into related groups, and random events in small samples easily give extreme results. How often do you roll three avalanches on three dice, or two avalanches and a mammoth stampede? I'd like more evidence before saying the "blitzkrieg" scenario is the most likely.
So, another possibility, as you hint, there could still be living groups with Neanderthal mitochondrial DNA that haven't been sampled by a passing geneticist. Ah, Vociferous seems to be proving us both wrong :-)
"No Neanderthal mitochondrial DNA has been found in our genome"
That is false. By carrying out an extremely tendentious analysis, Pääbo concluded that mitochondrial DNA from Neanderthals clustered outside a small selection of analogous mitochondrial DNA sequences from contemporary humans. Quite apart from the fact that the method of analysis he used had never been used before and has never been used again, it turns out that more dense sampling of current humans collapses the node separating neanderthals from current humans. This despite the fact that 50 000 years of interbreeding and coalescence separates current humans from the Neanderthals.
Pääbo's study was simply bad.