A Draft Sequence of the Neandertal Genome

A Draft Sequence of the Neandertal Genome

Neandertals, the closest evolutionary relatives of present-day humans, lived in large parts of Europe and western Asia before disappearing 30,000 years ago. We present a draft sequence of the Neandertal genome composed of more than 4 billion nucleotides from three individuals. Comparisons of the Neandertal genome to the genomes of five present-day humans from different parts of the world identify a number of genomic regions that may have been affected by positive selection in ancestral modern humans, including genes involved in metabolism and in cognitive and skeletal development. We show that Neandertals shared more genetic variants with present-day humans in Eurasia than with present-day humans in sub-Saharan Africa, suggesting that gene flow from Neandertals into the ancestors of non-Africans occurred before the divergence of Eurasian groups from each other.

To cut a long story short…

The authors suggest that non-Africans having about 1-4% Neanderthal ancestry is the most likely explanation for the variation in the DNA they have found. It’s not an absolute. A much less likely but not impossible scenarios is that the variation is due to population structure in Africa prior to the OOA, which may relate with the earlier separation of the ancestors of modern Africans and non-Africans inside Africa, although John Hawkes thinks this is so unlikely he was surprised they gave it space on the paper.

But, considering the number of genes in non Africans that have a time depth that is considerably older than the OOA movement (over 1 million years on one in one study by Hammer et al), and I think there is now decent evidence for Neanderthal ancestry in non-Africans.

I have some issues with the paper. Modern humans were in the near East about 120k ago, keeping company with Neanderthals for many millennia, but the interbreeding date comes out at 80,000 to 50,000 years. What were they doing with the rest of the time?

Such a scenario is compatible with the archaeological record, which shows that modern humans appeared in the Middle East before 100,000 years ago whereas the Neandertals existed in the same region after this time, probably until 50,000 years ago.

  And they observe that modern Europeans don’t seem to have a higher amount of Neanderthal ancestry than anyone else. But then they add:

 This possibility can be addressed by the determination of genome sequences from pre agricultural early modern humans in Europe (85). It is also possible that if the expansion of modern humans occurred differently in Europe than in the Middle East, for example by already large populations interacting with Neandertals, then there may be little or no trace of any gene flow in present-day Europeans even if interbreeding occurred.  

Which is what I suspect is more likely. I’d also like to address the apparent lack of modern human ancestry in the Neanderthals: well a quick look at the dates of the remains sampled; not younger than 38,000 BP. Which is prior to the date modern humans started to move into that part of Europe. Possibly a future investigation of later dated remains would show some AMH ancestry in them, as their appearance suugests they may be hybrids. I think the  Lagar Velho specimen would be a possible source, although it would be a pity to damage the specimen, possibly the Gorham’s Cave bones could yield relevant information.

So, non-Africans are definitely part Neanderthal

Finally the DNA evidence is in from Paabo ect. I thought I detected signs of a back track last year when he said they had probably had sex.

Neanderthal Genome Yields Insights Into Human Evolution and Evidence of Interbreeding With Modern Humans

 “We can now say that, in all probability, there was gene flow from Neanderthals to modern humans,” said the paper’s first author, Richard E. (Ed) Green of the University of California, Santa Cruz.

I’m trying to locate the full text for the Science article later. But my PC time is a bit limited today. However, I am officially entering smug mode now. Told you so.

I image there are a few anthropologists hopping up and down like excited orangutans right now at the news. To quote John Hawks:

Out-of-Africa movement was a major mechanism of recent human evolution. The genetic ancestry of living people is multiregional.

And

It does define all non-Africans today as an interspecific hybrid population.

From the article..

“The scenario is not what most people had envisioned,” Green said. “We found the genetic signal of Neanderthals in all the non-African genomes, meaning that the admixture occurred early on, probably in the Middle East, and is shared with all descendants of the early humans who migrated out of Africa.”

Which would suggest that the Levant, where modern humans and Neanderthals co-existed for some time about 120k ago was a mixing place for the two. According to the article, between 1% nd 4% of the genomes of non-Africans in Neanderthal in origin, which pretty much tallies with some of the older studies done (they are on the blog if you want to hunt them down).

The estimate of the time of admixture is around 50,000-80,000 years, however I’m not really sure why that should be correct, seeing as they first encountered each other prior to the ‘beach buggy’ colonisation of S/SE Asia, which would kind of place 80k as a bare minimum age, and more like 100k as there is some evidence of modern humans in SE Asia 74k ago under the Toba ash (necessitating a dispersal date for SE Asian populations of about 95k min). I also wonder what implications this has for the route out of Africa, as an exit via the Gate of Tears would make it less likely they’d come into contact with the Med coast Neanderthals of the era. I wonder if the number is more a composite of the very early mix in the Levant, followed by a later addition of Neanderthal DNA in Europe.

Having a happy day 🙂

IQ Population Genetics: It’s not as Simple as You Think

IQ Population Genetics: It’s not as Simple as You Think

A paper I came across while blog surfing. While the IQ stuff is interesting, what really caught my attention was the section on the out of Africa date.

Both genetic evidence (Ingman et al., 2000; Underhill et al., 2001; Zhivotovsky et al., 2003) and the fossil record (White et al., 2003) point to Africa as the likely homeland of our species. According to the most widely accepted scenario, one or more subgroups of early modern humans left Africa between 120,000 and 100,000 years ago to become the ancestors of the non- African populations

Which makes a pleasant change after reading an idiot paper earlier today that was hitting the 40k date. Again.

 And something I didn’t know..

Genes, like drugs, have many side effects. This is called pleiotropy. For example, the average IQ of nearsighted people is 6 to 8 points higher than the average for normal-sighted people.

Although I am familiar with a medical condition called torsion dystonia that raises the IQ of the sufferer by an average of 10 points. An interesting read.

Brain size, relative intelligence, sex and fat.

After re-reading the ludicrous (and I’ll explain why it’s ludicrous) assertion that women have an average IQ five points lower than the male claims from Lynn, I thought I’d dig up some of the facts and figures surrounding this flawed work.

First of all I’m going to put a link to this paper on relative brain size and intelligence by Tom Schoenemann, a professor whose specialist field is the evolution of the human brain. It has several numbers relevant to this subject:

Male:          (55.5 kg body weight, 1361 g brain weight)
Female:    (51.5 kg body weight, 1228 g brain weight)

As you can see, the human male appears to have a brain size proportionally slightly larger than the female. However, one thing  routinely ignored in all these measurements is fat. The average human male  (Western) carries a body fat of about 16%, women carry about 22%. Which means you need to calculate the relative brain size compared to non-fat mass, as fat is a null factor and as far as anyone can tell requires no processing power to control. My IQ at nine stone would be exactly the same if I weighed ten stone, although my relative brain size would have decreased due to the extra fat I now carried. This does not apply to long-term obesity which affects the brain, but the mere gaining of a few pounds has no known effect on IQ.

So from the numbers above the  you would have 25.52 g of brain per kg of body mass (male) vs 23.84 g (female). The female comes out as 93.4% the relative size of the male from this.

Factoring in the difference in body fat… 

 male       55.5- 8.88 (16% fat)  =  46.62  for 1361g, or 29.19g/kg

female    51.5 – 11.33 (22% fat) = 40.17 for 1228g, or  30.57g/kg

And all of a sudden the ‘large relative difference’ (16.6% here) between male and female brain size does a vanishing act. Here women actually seem to have a slightly larger relative brain size, although this may well be from the body fat percentages I used here being slightly askew. I’m not claiming that the percentage for body fat is 100% accurate, and if anyone reading this can link me to a study with the exact figures I’d be grateful, but you get the ballpark idea here.

In the Lynn study he comments how women seem to be doing better than men in spite of having a lower IQ; which suggests to me that the tests he and his colleagues were using were hinky. One of the main uses for IQ tests is to predict academic ability, and really all that Lynn’s test did was establish that his did not measure academic ability well in women or men, which pretty much proved it was slightly biased in favour of the male, and therefore not an accurate measure of intelligence. Gender biasing an IQ test is easy to do if you put in a few extra maths questions and remove a few language questions (in favour of the male). Something similar happened in the early days of IQ testing when a series of IQ tests found women to have a notably higher IQ, until they ‘balanced’ the test out.

This really goes towards ‘what are IQ tests and do they measure general intellegence’ debate. So far (poll a few psychologists) the consensus is that IQ tests are a real indicator of your general intelligence level and are a good predictor of your life outcome. If they weren’t relevant to real life/academic success, the only thing an IQ test would indicate would be how good you are at IQ tests, and your score wouldn’t be even remotely related to how smart you are (see earlier point about the tests Lynn used).

Going back to the Schoenemann paper, he makes it very clear that so far relative brain size and IQ are very strongly correlated:

“It is quite simply a myth that brain size and  IQ are empirically unrelated in modern populations.”

So far all the studies I’ve seen show a correlation between general brain size and IQ of about .4, which is statistically significant. I’m wondering if a more focused MRI/IQ brain size study vs non-fat body mass would reveal a much higher correlation for humans than this.

But essentially, functionally identical relative brain size (when fat is factored in) for male and female makes Lynn’s claims for a 5 point difference extremely hard to support, even more so when he admits that the tests used did not accurately predict academic outcome for the women who took them. In fact, he himself has commented on how racial difference in IQ are supported by the difference in relative brain mass. So how, with no quantitive difference between sexes in relative brain mass, can his claims for a lower average female IQ be correct?

It can’t.

Shame on you for bad science, Dr Lynn.

The lineage of King Tutankhamun from ancient DNA analysis

The news of the month, kindly posted to me by a friend, is that they have proved via ADNA that the mummy from tomb Kv55 is Akhenaten, son of Amenhotep III and king Tutankhamun’s father, and that the younger lady (KV35) is his mother. It also seems Tut died of malaria and suffered congenital deformities, which I’d guess were the result of incestuous marriages in the royal family. This means that the prior ageing of KV55 as 18 was way off.

This also mean that queen the red-haired queen Tiye (elder lady mummy) was the mother of Kv35 (using logic, they all have the same mt DNA), which might explain why they were found in the same tomb.

I’ve prepared a brief genealogy.

      

Known grandparents  

 Amenhotep III  and Tiye (whose parents were Tuya and Yuya)

     File:KV55 scull.jpg   

Known parents

Akhenaten (Kv 55)  and  (KV 35).

The actual name of KV35 uncertain but she has been suggested as Nefertiti, these were brother and sister.

 

 Tutankhamun, who appears to have also married his sister Ankhesenamun.

It would be interesting to see if the mummy in Kv21A is indeed Tut’s wife Ankhesenamun, as she is known to be the daughter of Nefertiti and Akhenaten, and this could give a definitive answer as to whether Kv35 is in fact Nefertiti.  Ankhesenamun has been identified as the mother of one of the fetuses from Tut’s tomb, so this might be on the cards for the future.

Ancestry and Pathology in King Tutankhamun’s Family
Zahi Hawass, PhD; Yehia Z. Gad, MD; Somaia Ismail, PhD; Rabab Khairat, MSc; Dina Fathalla, MSc; Naglaa Hasan, MSc; Amal Ahmed, BPharm; Hisham Elleithy, MA; Markus Ball, MSc; Fawzi Gaballah, PhD; Sally Wasef, MSc; Mohamed Fateen, MD; Hany Amer, PhD; Paul Gostner, MD; Ashraf Selim, MD; Albert Zink, PhD; Carsten M. Pusch, PhD
JAMA. 2010;303(7):638-647.

Context

  The New Kingdom in ancient Egypt, comprising the 18th, 19th, and 20th dynasties, spanned the mid-16th to the early 11th centuries BC. The late 18th dynasty, which included the reigns of pharaohs Akhenaten and Tutankhamun, was an extraordinary time. The identification of a number of royal mummies from this era, the exact relationships between some members of the royal family, and possible illnesses and causes of death have been matters of debate.

Objectives

  To introduce a new approach to molecular and medical Egyptology, to determine familial relationships among 11 royal mummies of the New Kingdom, and to search for pathological features attributable to possible murder, consanguinity, inherited disorders, and infectious diseases.

Design

  From September 2007 to October 2009, royal mummies underwent detailed anthropological, radiological, and genetic studies as part of the King Tutankhamun Family Project. Mummies distinct from Tutankhamun’s immediate lineage served as the genetic and morphological reference. To authenticate DNA results, analytical steps were repeated and independently replicated in a second ancient DNA laboratory staffed by a separate group of personnel. Eleven royal mummies dating from circa 1410-1324 BC and suspected of being kindred of Tutankhamun and 5 royal mummies dating to an earlier period, circa 1550-1479 BC, were examined.

Main Outcome Measures

  Microsatellite-based haplotypes in the mummies, generational segregation of alleles within possible pedigree variants, and correlation of identified diseases with individual age, archeological evidence, and the written historical record.

Results

Genetic fingerprinting allowed the construction of a 5-generation pedigree of Tutankhamun’s immediate lineage. The KV55 mummy and KV35YL were identified as the parents of Tutankhamun. No signs of gynecomastia and craniosynostoses (eg, Antley-Bixler syndrome) or Marfan syndrome were found, but an accumulation of malformations in Tutankhamun’s family was evident. Several pathologies including Köhler disease II were diagnosed in Tutankhamun; none alone would have caused death. Genetic testing for STEVOR, AMA1, or MSP1 genes specific for Plasmodium falciparum revealed indications of malaria tropica in 4 mummies, including Tutankhamun’s. These results suggest avascular bone necrosis in conjunction with the malarial infection as the most likely cause of death in Tutankhamun. Walking impairment and malarial disease sustained by Tutankhamun is supported by the discovery of canes and an afterlife pharmacy in his tomb.

Conclusion  Using a multidisciplinary scientific approach, we showed the feasibility of gathering data on Pharaonic kinship and diseases and speculated about individual causes of death.

According to someone (not me) who has been bothered to enter the Y chr markers as seen on the video, Tut is coming up as R1b. I’d have put money on it being something more like an E1 Y chr, or maybe J as an outside chance…R1b isn’t unknown in Egypt, (see Wood 2005) but isn’t exactly common. R1b appears to have entered Africa from Asia sometime in the Neolithic along with Afro-Asiatic, which is really all I have to say until I get a published source and more detail. Can’t get any detail on the mt DNA, unfortunately. 

For anyone interested, there’s a bunch of videos at the Discovery Channel site about this, with some good shots of Akhenaten in his coffin.

Taforalt man into the Sahara.

L’homme de Taforalt au Sahara, ou le problème de l’extension saharienne des Cromagnoïdes du Maghreb

The important discovery of a cro Magnon settlement in the Southernmost Sahara  dating to the Holocene brings new data on the morphological and geographical evolution of the Cro Magnon population of the Maghreb (Men of Mechta-Afalou-Taforalt). The great resemblance between the men of Taforalt and those of the Sahara (Hassi-el-Abiod, Mali) pose the problem of their origins. Was it a migration from the Maghreb at the beginning of the Holocence aided by favourable climate conditions or regional evolution from the regional Aterien stock mixing with the Cro Magnons of the Maghreb and the Sahara? The numerous climatic changes occurring in this part of the Sahara during the last 30,000 years could be an efficient evolutive promoter and can explain the morpholgical and cultural differences observed between the Sahara and Maghrebian series. However, what will happen later to African Cro magnids in the Maghreb and especially in the Sahara is still an open question.

 I’m not going to translate the whole thing, but it observes that the Mechtoids vanish about 7,0oo years ago (very latest site in the Sahara, but they are gone by 10,000 Bp at the coast when the Capsian culture arrives from the near east) when the proto- mediterranoids arrive, and they are not found in later sites. When I have a little more time I’ll make up a more comprehensive entry involving this and the other work on mechtoid populations and genetics that should explain their origins and relationships a bit more clearly. Please excuse my imperfect translation.

Conclusion

These new discoveries bring three new basic concepts; firstly, African Cro Magnids occupied a vast part of the North of  Africa of the end of Pleistocene until  the beginning of  the Holocene; secondly in spite of regional morphological characteristics, all Mechtoids belong to the same group; thirdly these facts suggest the existence of a common ancestor to these three populations and this ancestor could be represented, until there are other older discoveries, by the Aterian people.

Which I’d have to disagree with, as the stone tool cultures and genetics suggest an expansion from Lower Nubia/Egypt about 24k ago that spawned off the Mechtoid/Kebaran populations, which was roughly equal in terms of back-migrating Eurasian and Nubian-African ancestry. Except for the Taforalt population, which ADNA has shown was entirely Eurasian for mt DNA, and may have been the result of a migration southwards across the straits of Gibraltar about the time of the LGM (20k ago) mixing with the local Mechtoids.

On the Concept of Biological Race and Its Applicability to Humans

On the Concept of Biological Race and Its Applicability to Humans
Kaplan, Jonathan and Pigliucci, Massimo (2002)

Abstract
Biological research on race has often been seen as motivated by or lending credence to underlying racist attitudes; in part for this reason, recently philosophers and biologists have gone through great pains to essentially deny the existence of biological human races. We argue that human races, in the biological sense of local populations adapted to particular environments, do in fact exist; such races are best understood through the common ecological concept of ecotypes. However, human ecotypic races do not in general correspond with `folk` racial categories, largely because many similar ecotypes have multiple independent origins. Consequently, while human natural races exist, they have little or nothing in common with `folk` races.

A paper from 2002 that I hadn’t read until today. Yet another nail in the coffin of  ‘genetics has proved there’s no such thing as race’.  I kind of skimmed it (ashamed), but these sections leapt out at me:

Lewontin and Gould have made much of the fact that there is relatively little genetic variation in Homo sapiens (compared at least to other mammals; see Templeton 1999) and that most of what genetic diversity is known to exist within Homo sapiens exists within (rather than between) local populations (see, for example, Gould 1996; Lewontin et al. 1984), and these facts are cited repeatedly in arguments concluding that there are no biologically significant human races. But the idea that this data might imply something about the existence of biologically significant human races emerges from a focus on the wrong sort of biological races.

The question is not whether there are significant levels of between-population genetic variation overall, but whether there is variation in genes associated with significant adaptive  differences between populations (see our discussion in Kaplan and Pigliucci 2001).

But while skin color is not well correlated with other phenotypic traits of interest in humans, there is, despite Gould’s claims (Gould 1996) to the contrary, no guarantee that particular populations of humans will not, due to particular features of their environment, share particular distributions of adaptive behavioral (including intellectual) traits, as opposed to simple physical traits. To the best of our knowledge, there is no evidence that such populations exist, nor are there reasons to suppose that such populations must exist.

I’ve notice that on the no-race side of the fence, they constantly focus on genotypic variation, which is a bit of a red herring as it is phenotypic variation that really defines a race or sub species. Which is more or less what this essay points out.

Possible Neolithic cannibalism in Germany

This one  is all over the news today. At a site dating to 7,000 BP in Herxheim, Germany, they have found human remains that seem to bear the signs of being butchered for meat. While this isn’t pleasant, it’s not exactly unheard of from many locations around the world. But the scale, about 500 victims- possibly up to 1000, is unusual.

That’s a lot of corpses for a tiny Stone Age village. There were 10 buildings at most here in the last phase of the Linear Pottery culture of the European Neolithic Age around 5,000 to 4,950 years BC. The corpses weren’t native to this area, researchers have discovered. They came from all over Europe — from the area of what is now Paris, from the Moselle River 100 kilometers to the northwest and even from the Elbe River valley some 400 kilometers away. The broken bits of pottery lying between their ribs reveal their origin. It’s the so-called Linear Pottery that gave the entire population group its name: decorated with linear patterns pressed into the moist clay while it was being made.

 I’d recommend going to the this news article which has a lot of images and more information than I just can’t be bothered to type in right now. The ceramics were apparently from the Paris and Elbe valley about 400 kilometres away, showing how far people had come to get to the site. 

There’s a link to the magazine the full article was in (you need to subscribe).

There’s some disagreement as to whether the people were eaten, the remains seem to have been people in good health and not killed in battle, that had been brought to the region with ceramics that were broken at the site.  It’s quite possible this was some kind of religious behaviour involving de-fleshing of the bones rather than cannibalism. This behaviour only seems to have lasted for a 50 year time span.

Note: I will get around to clearing the comments backlog- I’m down to 200 now…be patient.

Neanderthals ‘had sex’ with modern man

Neanderthals ‘had sex’ with modern man

From an article in the Times

Modern humans and Neanderthals had sex across the species barrier, according to a leading geneticist who is overseeing a project to compare their genomes.

Professor Svante Paabo, director of genetics at the renowned Max Planck Institute for Evolutionary Anthropology in Leipzig, will shortly publish his analysis of the entire Neanderthal genome, using DNA retrieved from fossils. He aims to compare it with the genomes of modern humans and chimpanzees to work out the ancestry of all three species.

I can’t say I’m surprised to see this. Later (transitional) Neanderthals picked up modern human traits like chins and more complex burial rituals, and a few sets of remains do look hybrid. If you look at the more recent reconstructions such as ‘Wilma’ (from Nat geo), they don’t look massively different to modern humans.

In addition to this there are numerous DNA studies that suggest a low level on Neanderthal contribution to Europeans (5% or less seems the norm) even though Neanderthal mitochondrial DNA and Y chromosomes are absent.

Out of Africa again and again

Possible Ancestral Structure in Human Populations

Archaic admixture in the human genome

Detecting ancient admixture and estimating demographic parameters in multiple human populations

There are a few more, but you get the point.

From looking at the difference between Mesolithic and modern Europeans mt DNA, I know that it would be easy to lose a small minority contributor through drift, and it’s unlikely that (as a group being exterminated)  male Neanderthals would have made any kind of traceable contribution, as females may be absorbed from lower status groups, but males usually aren’t.

Theres also a  vid which mentions the subject by Prof Paabo on the subject on Youtube. I guess we’ll just have to wait and see.

We aren’t all the same- science is finding evidence of genetic diversity between populations as well as between individuals

Let’s celebrate human genetic diversity

Bruce Lahn and Lanny Ebenstein Nature, 8 October 2009

Science is finding evidence of genetic diversity among groups of people as well as among individuals. This discovery should be embraced, not feared, say Bruce T. Lahn and Lanny Ebenstein.

A growing body of data is revealing the nature of human genetic diversity at increasingly finer resolution. It is now recognized that despite the high degree of genetic similarities that bind humanity together as a species, considerable diversity exists at both individual and group levels (see box, page 728). The biological significance of these variations remains to be explored fully. But enough evidence has come to the fore to warrant the question: what if scientific data ultimately demonstrate that genetically based biological variation exists at non-trivial levels not only among individuals but also among groups? In our view, the scientific community and society at large are ill-prepared for such a possibility. We need a moral response to this question that is robust irrespective of what research uncovers about human diversity. Here, we argue for the moral position that genetic diversity, from within or among groups, should be embraced and celebrated as one of humanity’s chief assets.

The current moral position is a sort of ‘biological egalitarianism’. This dominant position emerged in recent decades largely to correct grave historical injustices, including genocide, that were committed with the support of pseudoscientific understandings of group diversity. The racial-hygiene theory promoted by German geneticists Fritz Lenz, Eugene Fischer and others during the Nazi era is one notorious example of such pseudoscience. Biological egalitarianism is the view that no or almost no meaningful genetically based biological differences exist among human groups, with the exception of a few superficial traits such as skin colour. Proponents of this view seem to hope that, by promoting biological sameness, discrimination against groups or individuals will become groundless.

We believe that this position, although well intentioned, is illogical and even dangerous, as it implies that if significant group diversity were established, discrimination might thereby be justified. We reject this position. Equality of opportunity and respect for human dignity should be humankind’s common aspirations, notwithstanding human differences no matter how big or small. We also think that biological egalitarianism may not remain viable in light of the growing body of empirical data.

Many people may acknowledge the possibility of genetic diversity at the group level, but see it as a threat to social cohesion. Some scholars have even called for a halt to research into the topic or sensitive aspects of it, because of potential misuse of the information. Others will ask: if information on group diversity can be misused, why not just focus on individual differences and ignore any group variation? We strongly affirm that society must guard vigilantly against any misuse of genetic information, but we also believe that the best defence is to take a positive attitude towards diversity, including that at the group level. We argue for our position from two perspectives: first, that the understanding of group diversity can benefit research and medicine, and second, that human genetic diversity as a whole, including group diversity, greatly enriches our species. 

Emerging understanding of human genetic diversity

Genetic diversity is the differences in DNA sequence among members of a species. It is present in all species owing to the interplay of mutation, genetic drift, selection and population structure. When a species is reproductively isolated into multiple groups by geography or other means, the groups differentiate over time in their average genetic make-up.

Anatomically modern humans first appeared in eastern Africa about 200,000 years ago. Some members migrated out of Africa by 50,000 years ago to populate Asia, Australia, Europe and eventually the Americas. During this period, geographic barriers separated humanity into several major groups, largely along continental lines, which greatly reduced gene flow among them. Geographic and cultural barriers also existed within major groups, although to lesser degrees.

This history of human demography, along with selection, has resulted in complex patterns of genetic diversity. The basic unit of this diversity is polymorphisms — specific sites in the genome that exist in multiple variant forms (or alleles). Many polymorphisms involve just one or a few nucleotides, but some may involve large segments of genetic material. The presence of polymorphisms leads to genetic diversity at the individual level such that no two people’s DNA is the same, except identical twins. The alleles of some polymorphisms are also found in significantly different frequencies among geographic groups. An extreme example is the pigmentation gene SLC24A5. An allele of SLC24A5 that contributes to light pigmentation is present in almost all Europeans but is nearly absent in east Asians and Africans.

Given these geographically differentiated polymorphisms, it is possible to group humans on the basis of their genetic make-up. Such grouping largely confirms historical separation of global populations by geography. Indeed, a person’s major geographic group identity can be assigned with near certaintly on the basis of his or her DNA alone (now an accepted practice in forensics). There is growing evidence that some of the geographically differentiated polymorphisms are functional, meaning that they can lead to different biological outcomes (just how many is the subject of ongoing research). These polymorphisms can affect traits such as pigmentation, dietary adaptation and pathogen resistance (where evidence is rather convincing), and metabolism, physical development and brain biology (where evidence is more preliminary).

For most biological traits, genetically based differentiation among groups is probably negligible compared with the variation within the group. For other traits, such as pigmentation and lactose intolerance, differences among groups are so substantial that the trait displays an inter-group difference that is non-trivial compared with the variance within groups, and the extreme end of a trait may be significantly over-represented in a group.

Several studies have shown that many genes in the human genome may have undergone recent episodes of positive selection — that is, selection for advantageous biological traits. This is contrary to the position advocated by some scholars that humans effectively stopped evolving 50,000–40,000 years ago. In general, positive selection can increase the prevalence of functional polymorphisms and create geographic differentiation of allele frequencies. 

A news worthy article, that won’t probably get the attention it deserves in the general media. I’ve noticed over the past few years more and more papers are being published along these lines, and I’d just like to applaud them for having the courage to put this in print, as this kind of published work (observing what are essentially racial differences) can really endanger your career. Most notable was this …

It is now recognized that despite the high degree of genetic similarities that bind humanity together as a species, considerable diversity exists at both individual and group levels

Which really goes counter to what it generally presented to the public in those cosy channel four and BBC documentaries like ‘In the blood’  and ‘ Race, the last taboo’. Prof. Jones will not be a happy man when he reads this. Also worthy of attention was this (condensed, it’s in the text as a whole) …

Biological egalitarianism is the view that no or almost no meaningful genetically based biological differences exist among human groups …..We believe that this position, although well intentioned, is illogical and even dangerous…We also think that biological egalitarianism may not remain viable in light of the growing body of empirical data.

So there you go. We aren’t all the same. I’ve believed for the past seven years, ever since I started to show a deeper interest in anthropology and genetics, the ‘no such thing as race’ paradigm was driven by (well meant) egalitarianism ideology and not fact. If there’s no such thing as race, there can’t be racial differences and, ergo, no racism. I think that Lahn’s and Ebenstein’s hopes for a grown up acceptance of between-group differences may be unfulfilled, as the average human just isn’t that reasonable.