The actual study found that Neanderthal DNA is present in a small percentage (not all) of people in each continent. Including Africa.
Anyone contemplating downvoting this, for the love of scientific reality please read the actual original paper first.
Anyway, the fact that Neanderthal sequence is present in all non-African populations is more important and interesting than whether or not Neanderthal sequence is present in all non-African human individuals. By statistical likelihood, we'd expect the answer to the latter question to be 'no', while the answer to the former is interesting, empiric, and, now, known to be 'yes'.
It's also not true what both titles suggest that no African samples were part neandertal, the supposed neandertal segment (B006) was found in several African samples from their extremely limited sample size that doesn't even cover a small fraction of ethnic populations of Africa. Not only is it present in several African samples they tested, it is likely to be found in others as well should this be extended to a more comprehensive sample of world ethnic groups.
As a completely separate topic, the uniquely Neandertal origin of B006 is speculative to say the very least, but it's fine to assume so for the sake of argument, it's just not a definitive claim of fact... yet.
To be clear, are you saying the more accurate statement would be: "Neandertal chromosome segments found in all tested non-african populations, and some tested african populations"? (Which, when you put it that way, seems like a somewhat weird distinction to make.)
edit: I followed the link upthread, but it was only to the paper abstract. Is the full paper available for free online somewhere?
edit2: It seems the distinction might be no neandertal geneds found in sub-Saharan African population samples?
Yes, your more accurate statement is correct.
> "It seems the distinction might be no neandertal genes found in sub-Saharan African population samples?"
Regarding the Sub-Saharan distinction, the article text's terminology describes haplotype B006 as "virtually" absent from Subsaharan Africa. They then explain this as meaning that 6 out of the 1420 subsaharan samples contained B006, including 5 from tribal groups in Burkina Faso. They explain this away by supposing that these tribal groups must have historically interbred with north African groups, which is not an unreasonable guess, but I am sure it is also true for many other subsaharan groups as well. North African incidence rates of B006 are comparable to the middle east and Russia and higher than China.
So, 0.4% of sub-saharan samples contained B006, but not none. Also, north-western mexico, east south america, east china, siberia and indonesia all have similarly extremely low incidence rates, but no explicit mention of these areas is made in the paper, it's just seen in the data. Only subsaharan africa is called out for special mention. The highest rates of B006 are in western Canada - greater than 25% in some areas.
There is also a separate problem of the circular argument due to the inherent selection bias of brute force digging through the data sets looking for a gene with these characteristics. It's not like they started with a gene they knew was neandertal only, researchers sought out a gene in the single sequenced neandertal sample which had lower modern african incidence rates and from that concluded it was a non-african sourced neandertal gene, then turned around and concluded the reverse, bringing the argument full circle. That's another problem but I'd just as soon not get into that since I would much rather assume that is all good and only focus on the very misleading titles that are going around in articles about this paper.
There have been studies showing that individuals from two different races, for example Caucasian and West African, are usually more similar genetically to some members of the other race than to some of his own. What is meant by this? How is it possible considering that people of the same race share much more recent ancestry than people of different races? Then later you see graphs showing genetic clusters, how can there be clusters if people aren't more similar to one another for being of the same race? Did they use mixed race individuals for these studies? Are the parts of the genome that make two people look more similar to each other random parts or specific ones, what do these parts do? And finally in the global similarity section of 23andme, one can see the groups he's most related to, how is this possible?
I'm not up to date with the racial arguments you mention. I know there was something of an obsession 50-100 years ago with trying to establish a scientific basis to justify racism, imperialism, land theft, sterilization, imprisonment and subjugation of non-european peoples and there are still vestiges of those assumptions in a lot of research.
With the claim that "individuals from two different races, for example Caucasian and West African, are usually more similar genetically to some members of the other race than to some of his own", I have heard similar claims but how I understand it is they are not saying randomly chosen individuals from two different groups are more similar than randomly chosen individuals from within a group, but are comparing diversity of individuals within a group to diversity of group averages between groups. In other words, the claim is that the variation between two related individuals is greater than the variation between two unrelated groups, taken as averages. You are correct that if the claim is being presented that individuals between unrelated groups are more related than individuals within related groups, the argument doesn't make sense. It would not be surprising though if it has been presented that way in some articles and then repeated until it became a self-propagating myth. And again to clarify, I'm not up to date with any of those arguments, but just speculating on what might be going on.
I'm not arguing any position, just trying to understand without being very familiar with genetics or statistics. Maybe I've read the studies the way you presented it but my simple mind interpreted it that way. I'm guessing there is a huge flaw in what I drew but I don't see it, I can't picture in my mind what you meant.
The linked article is from the Discovery Channel, which as far as I can tell has different owners and isn't affiliated with Discover Magazine.
I wouldn't downvote you because you are necessarily wrong. In fact I don't think that is even suggested behavior. However, you probably should get downvoted for other reasons (http://ycombinator.com/newsguidelines.html#Be_Civil)
Also, for those of you who read this article, the Nick Patterson quoted in the article was, in another lifetime, a cryptologist: http://query.nytimes.com/gst/fullpage.html?res=990DE6D81431F...
One of the unfortunate side effects of the way that newspapers report on scientific research is that journalists' lack of knowledge of the subject matter leads to lots of vague statements that can be easily twisted around to have just about any desired meaning.
"We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights"
The other like this:
"We hold these truths to be self-evident, that all men (and women!) are absolutely inseparably as good as each other at sports, that they are endowed by their Creator with a complete knowledge of the rules of basketball"
The latter would be an absurd thing to say, but would be easy to judge empirically. The former is a statement of a certain set of values - widely held, I'd hope, but nevertheless impossible to justify experimentally, beyond the fact that (again, I'd hope) most people have experienced in their lifetimes that it's nice when we all get along with one another.
Either way, they use the concept of 'equality' quite differently. I felt Dove actually captured this very succinctly, which is why I'm surprised it's been misconstrued twice now.
Other places were able to get their own civilization thanks to one reason or the other, e.g. Eastern China.
All that has to do with achievements of different societies. Now at the individual level, how do we know whether groups with Caucasian genes would have been able to develop a civilization if they had lived in a place with the same geography and conditions as Sub-Saharan Africans? We can't know.
What we know though is that the conditions are there now for individuals with predominantly Sub-Saharan ancestry to show what they are capable of. Eventually they'll produce someone like Mozart, Newton, Confucius, Sun Tzu, Jabir ibn Hayyan or Abbas ibn Firnas. Or maybe they won't. Perhaps too early to tell.
>You have to keep in mind though that Timbuktu for example didn't spring out of nothing but thanks to Muslims from the North.
This would be like calling Sicilly an Arabic city. Timbuktu grew as a center of trade within Black Africa as a result of trade with the northern Arabic and Arabized Berber states. This does not make it any less valid as an example.
PS: May not look like it, but I largely agree with you.
Not necessarily. The first big European civilization was the [Cucuteni-Trypillian culture](http://en.wikipedia.org/wiki/Cucuteni-Trypillian_culture) which developed north-west of the Black Sea and was quite ahead of what was developing in the Middle East or elsewhere at the time (they had better pottery, barter tokens, biggest settlements in the World - up to 15000 people-, and were possibly the authors of the first writing system, 1000 years before the Summerians).
Now compare that with anything build by the Great Zimbabwe, Old Ghana or Timbuktu. Don't worry, that fortified church is just one of many.
Thanks for the Sicillian clarification BTW. I'll be sure to go there next time I'm in Greece. Oh, wait...
Africa is just too big and diverse too be lumped into one category. However I did get a good chuckle out of the jpeg.
I do have to agree with the some of the sentiments here. There are examples of Africans who also have the Neanderthal presence in their DNA, again, east-africans. Probably explains why they're so different to other Africans.
Though I still don't know whether they're considered sub-saharan africans or not. They are genetically very distinct from surrounding Africans.
PS: "Sub Saharan" is rather long. We really don't mind "Black" Africa.
Pictures results after googling around a bit:
In my opinion, this just shows that humanity is a gradient. Overlapping. It's rather fascinating.
Cushites - are "Black" in a political sense, maybe less so in a cultural sense as I've been made to understand that Ethiopians generally don't see themselves as lowercase "b" black.
About the gradient thing, black people have a huge spectrum of different skin colors, even within the same family. My Mum for instance, is light skinned. My sister and I are quite dark. The funny thing is we started out really light skinned as children, perhaps till we each turned three. I've heard some kids start out blonde and end up with dark hair? I find it all quite interesting.
But he said that you are correct, if you go in the north of Somalia, where currently, Somaliland is. You will find that many Isaacs ( clan name) think they are descendants of the arab tribe of Mohammed. My friend tells me these people are just confused. And I think we can agree that DNA analyses seem to suggest he's correct.hehe.
DNA and linguistic research seems to suggest the Earlier Egyptian,Somali, Amhara and Eritrean populations to be close relatives. With the Somalis having the least influence of surrounding nations ( Arabs, west-africans etc.)
Funny how the ones that don't think they're purely Africans, are the ones that in fact, are!
I hesitate to say this since I had been planning on staying away from this conversation, but northeast africa is not part of sub-Saharan Africa which this article seems to be concerning (at least according to the Discover writeup, which I only skimmed).
IIRC correctly, Neanderthals had smaller brains.
Neanderthal cranial capacity is thought to have been as
large as that of a Homo sapiens, perhaps larger,
indicating their brain size may have been comparable, as
well. In 2008, a group of scientists created a study using
three-dimensional computer-assisted reconstructions of
Neanderthal infants based on fossils found in Russia and
Syria, showing that they had brains as large as modern
humans' at birth and larger than modern humans' as
adults. On average, the height of Neanderthals was
comparable to contemporaneous Homo sapiens. Neanderthal
males stood about 165–168 cm (65–66 in), and were heavily
built with robust bone structure. They were much stronger
than Homo sapiens, having particularly strong arms and
hands. Females stood about 152–156 cm (60–61 in)
OTOH, in regard to the parent post, reason never stopped a racist before. It's doubtful it will now.
A snippet: "Really quick history lesson on Neanderthals. They are not an ancestor of modern humans. Homo neanderthalensis is descended from a separate branch that split off from the evolutionary tree about 516,000 years ago, according to some research published in Nature. Mitochondrial DNA studies have shown conclusively that Homo neanderthalensis and Homo sapiens evolved separately. As the Cro-Magnon Homo sapiens moved in across Europe about 45,000 years ago, Homo neanderthalensis was pushed out into little corners of the world. The last known population died out in the vicinity of Gibraltar about 24,000 years ago, thus ending their approximately 300,000 year existence.
So now we've got a fair handle on the landscape of evidence in front of us, and now we can take a skeptical look at what we've got. Basically, nothing. We have some vaguely plausible hypotheses — yeah, I suppose it's possible that relic Neanderthals and Gigantopithecus or even some descendant of Paranthropus could survive in remote parts of Asia — but that's all we really have, a hypothesis. A hypothesis is a provisional explanation for these stories of wildmen in captivity and bearing children."
Add to that the Denisova hominin sequencing (from the single toe bone that was thought to be Neandertal of a population that may have diverged from the African populations around 900kYA) and possible presence of up to a 4% admixture in Papuan and Melanesian populations.
It's exciting times to be interested in human evolution.
Remember that a 4% contribution is about what you might expect from a great-great grandparent (although we're talking whole populations here, not specific individuals).
My take home: the different clades of humans/hominins have been able to recognise enough of themselves in others that they were able to mix and interbreed. Early human prehistory wasn't just genocides and extinctions due to overspecialisation and ecological change. Awesome!
I have a feeling a lot of supremacists groups are going to start making a point of how superior Neanderthals were soon enough.
Basically, he's saying "hybrid vigor". Boom, there you go, supremacists, have fun!
Why mix when in the middle east and then refuse to mix when in Europe?
All life originated with a single common ancestor, but I still find distinctions to be useful. Neanderthals and humans were considered to be different species, so this is a fairly weighty finding. Anyway, making distinctions is perhaps the essence of being human.
Oh, right, I forgot that genetic research was per se racist. Or am I misinterpreting you?
The fact that sub-Saharan Africans are not of partial Neanderthal descent while every other race is does create the possibility that there are fundamental genetic differences between them and all other races. However, proving any such differences would be near impossible. What's racist is to claim that such differences exist when not a shred of scientific evidence for such a claim exists.