Category Archives: race

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.

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)

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.

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.

Lewontin’s fallacy

No, I’m not dead, just recovering from an MS attack that ‘turned off’ my curiosity and messed up my memory for a couple of months. I will look at the comments (all 254 of them) eventually.

I was slightly irked at watching channels 4’s shockingly bad and biased series on race, in which it trotted out Lewontin’s fallacy on the programs and on its supporting material on its site. All the criticisms I posted (they had an OOA date of 50k ago, don’t get me started…) have not been allowed through to the site, so I’m going to have a mini rant here. It’s not that they are supporting the ‘no race’ line (hey, you can disagree with me), but that they are pretending that it is the consensus view among anthropologists and geneticists- no-one is allowed to post the recent work that outright states that race is real.

First of all here is the article which explained why the claims for low diversity in humans were over exaggerated…

Human genetic diversity: Lewontin’s fallacy

In popular articles that play down the genetical differences among human populations, it is often stated that about 85% of the total genetical variation is due to individual differences within populations and only 15% to differences between populations or ethnic groups. It has therefore been proposed that the division of Homo sapiens into these groups is not justified by the genetic data. This conclusion, due to R.C. Lewontin in 1972, is unwarranted because the argument ignores the fact that most of the information that distinguishes populations is hidden in the correlation structure of the data and not simply in the variation of the individual factors. The underlying logic, which was discussed in the early years of the last century, is here discussed using a simple genetical example.


Worth a read.

What Dr Keita actually says about the race of the ancient Egyptians.

Much  beloved by the Afrocentrist idiots who like to pretend Keita believes and has proved Egyptians were black Africans.. I quote..

“it can be imagined that the modern diversity to be found in Egypt…. in terms of craniofacial features… skin colour… what have you, would likely have been very similar to that found in the past.”

He then goes on to point out that the heterogenous ‘mixed ancestry’ was there before the predynastic era (also true) and that the state formation was a local process (also true, it has a Badarian root). He then goes on to have a moan at Afrocentrists and Eurocentrists ( the real nuts  who think Egyptians were all Nordics).

Very enlightening.

Hanihara: Characterization of Biological Diversity Through Analysis of Discrete Cranial Traits

This is a 2003 publication showing the relationship of the worlds populations by studying the crania. This paper says that both multiregional and the out of Africa scenario are possible from these results. As can be seen on the dendrogram, the Egyptian samples (Gizeh and Naqada) are on the North African twig along with the Nubians, which are themselves very close to the European cluster, which supports the Loring Brace study showing ancient Egyptians as being non-similar to Sub Saharan Africans. In fact a look at all the diagrams shows Hanihara grouping the ancient North Africans closer to west Eyurasian groups.

The only downer is that modern North Africans aren’t included on this.



I’ve added colour to the diagrams as they are a little hard to make out if you have poor sight. Sub Saharan is red (Somalis have a black dot inside) and Europeans are blue, North African samples are bright green, and South Asian are violet.

Characterization of Biological Diversity Through Analysis of Discrete Cranial Traits
Tsunehiko Hanihara,1* Hajime Ishida,2 and Yukio Dodo3, 2003

ABSTRACT In the present study, the frequency distributions of 20 discrete cranial traits in 70 major human
populations from around the world were analyzed. The principal-coordinate and neighbor-joining analyses of Smith’s mean measure of divergence (MMD), based on trait frequencies, indicate that 1) the clustering pattern is similar to those based on classic genetic markers, DNA polymorphisms, and craniometrics; 2) significant interregional separation and intraregional diversity are present in Subsaharan Africans; 3) clinal relationships exist among regional groups; 4) intraregional discontinuity exists in some populations inhabiting peripheral or isolated areas. For example, the Ainu are the most distinct outliers of the East Asian populations. These patterns suggest that founder effects, genetic drift, isolation, and population structure are the primary causes of regional variation in discrete cranial traits. Our results are compatible with a single origin for modern humans as well as the multiregional model, similar to the results of Relethford and Harpending ([1994] Am. J. Phys. Anthropol. 95:249– 270). The results presented here provide additional measures of the morphological variation and diversification of modern human populations.

East Asians
1. Japanese 98–108 (94) 62–64 (59) Tokyo and Tohoku (Northern Japan) regions (UT, TU)
2. Hokkaido Ainu 122–151 (113) 84–108 (76) Recent Ainu people (SMU, UT)
3. Sakhalin in Ainu 62–65 (54) 28–29 (32) Southern Sakhalin (MAE, MSU, KU, MH)
4. North Chinese 132–139 (75) 26–27 (14) Mainly from Liaoning Prefecture (UT, KU) Southeast Asians
5. Myanmar 132–135 (48) 47–49 (3) Recent Burmese (NHM, UC)
6. Mainland SE Asians 125–141 (105) 41–43 (30) Thai, Vietnam, Laos, Cambodia, and Malay (NHM, UC, MH)
7. Javanese 94–97 (83) 32–26 (32) Greater Sunda islands (NHM, UC, MH, AMNH)
8. Philippines 135–144 (49) 62–66 (31) Non-Negrito Filipinos (NHM, UC, MH)
9. Borneans 78–109 (74) 37–40 (21) Mainly land Dayaks (NHM, UC, MH)
10. Lesser Sunda 52–54 (39) 11–12 (6) Timor, Bali, Sumbawa, Flores, and Celebes Islands (NHM, UC, MH, AMNH)
11. Andamanese/Nicobarese 65–71 (43) 40–43 (30) Andaman Negritos and Nicobar Islands (NHM, UC, MH)
Northeast Asians
12. Mongolians 116–121 (69) 53–59 (38) Ulan Bator (Urga) and other regions (MH, NMNH, AMNH)
13. Buryats 76–81 (65) 64–69 (58) From Northeast Siberia (MAE, MH, NMNH)
14. Amur Basin 85–92 (57) 67–74 (48) Ulchs, Nanaians, Negidals, Nivkhs, and Orochs (MAE, MSU, MH)
15. Neolithic Baikalians 40–59 (45) 14–22 (19) From around Lake Baikal (MAE, MSU, ISU)
16. Yakuts 43–45 (38) 19–20 (18) From Northeast Siberia (MAE, MSU, MH) Arctic
17. Ekvens 45–55 (48) 49–56 (44) Iron-Age people from Ekven site, Chukot Peninsula (MSU)
18. Chukchis 43–48 (17) 22–26 (10) From Arctic region of Northeast Siberia (MAE, MSU, MH, NMNH, AMNH)
19. Aleuts 63–67 (48) 30–43 (17) Mainly from Unalaska Island (NMNH, AMNH)
20. Asian Eskimos 66–73 (48) 53–59 (16) From Arctic region of Northeast Siberia (MAE, MSU)
21. Greenland Eskimos 82–85 (47) 70–76 (25) West Coast of Greenland (NHM, UC, MH, AMNH, NMNH)
New World
22. Northwest Coast 53–59 (15) 29–35 (12) Northwest Coast of Canada (NHM, UC)
23. Northwest America 48–61 (40) 19–24 (16) Plateau, Great Basin, California, and Southwest Cultural
areas (NHM, UC, MH)
24. Northeast America 42–50 (20) 21–29 (8) Great Plains, Northeast, and Southeast Cultural areas
25. Central America 45–58 (21) 24–30 (12) Mexico, Colombia, Ecuador, Carib, Venezuela, and Guyana
26. Peruvians 115–123 (60) 55–60 (33) Cerro del Oro, Huacho, Pisagua, etc. (NHM)
27. Fuegians/Patagonians 39–44 (24) 20–23 (7) Terra del Fuego and Patagonia region (NHM, UC, MH)
28. Mariana 91–120 (82) 70–93 (75) Guam, Saipan, and Tinian (BM, MH) Polynesians
29. Hawaii 82 (58) 63–64 (42) Mainly from Oahu Island (NHM, UC)
30. Easter 63–79 (41) 59–71 (31) Easter Islanders (NHM, UC, MH, AM, US, SAM)
31. Marquesas 55–61 (24) 39–42 (9) Mainly from Uahuka Island (NHM, MH)
32. Maori 109–140 (58) 37–49 (23) New Zealand (NHM, UC, AM, US, SAM)
33. Moriori 66–78 (24) 18–20 (6) Chatham Islands (NHM, UC, AM, US) Melanesians
34. Papua New Guinea 54–175 (84) 51–154 (83) Purari River delta, Fly River delta, Sepik River Delta, etc.
35. Torres Strait 59–65 (37) 35–38 (37) Island of Torres Strait (NHM, UC, MH)
36. North Melanesians 64–196 (119) 41–103 (72) New Ireland, New Britain, Solomon, and Santa Cruz (NHM,
37. South Melanesians 58–137 (67) 27–57 (33) Loyalty, New Caledonia, Vanuatu, and Fiji (NHM, UC, AM,
38. East Australians 53–88 (55) 33–46 (36) New South Wales, Queensland, and Victoria (AM, NHM, UC, MH, AMNH)
39. South/West Australians 86–260 (159) 34–128 (77) South Australia and Western Australia (SAM, NHM, UC, MH, AMNH)
Tibet/Nepal/Northeast India
40. Tibetans/Nepalese 91–94 (58) 23–25 (4) Tibetan Soldiers (19th Century), lowland of Nepal (NHM,
41. Assam/Sikkim 40–41 (30) 23–24 (19) Darjeeling, Assam, and Sikkim districts (NHM)
South Asians
42. Northeast India 90–93 (61) 23–24 (14) Bengal and Bihar districts (NHM)
43. South India 123–127 (65) 45–46 (30) Madras, Tamil Natu, Malabar Coast, and Karnataka (NHM)
44. Northwest India 125–131 (71) 32–35 (16) Punjab and Kashmir districts (NHM)
Central Asians
45. Tagars 62–72 (44) 60–76 (50) Iron-Age Tagar culture (MAE, MSU)
46. Kazakhs 75–77 (75) 42–43 (42) From Central Asia, Kazakh (MAE)
47. Russians 72–74 (74) 45–47 (41) Recent Russians (NHM, UC, MAE, MSU)
48. Greece 46–54 (20) 12–16 (4) Ancient and recent Greece (NHM)
49. Eastern Europeans 80–98 (52) 18–24 (16) Slav group: Poland, Czecho, Hergegovina, Bulgaria, and
Yugoslavia (NHM)
50. Italy 131–146 (82) 42–47 (31) Recent Italians (NHM)
51. Finland/Ural 72–75 (35) 5–6 (2) Including a few samples of Ural-language people (NHM, MH)
52. Scandinavia 57–60 (30) 5 (3) Norwegians and Swedish (NHM, UC)
53. Germany 58–61 (44) 9–10 (7) Recent German (NHM, UC)
54. France 74–86 (23) 18–21 (0) Recent French (NHM, UC, MH)
UK series
55. Ensay 64–68 (58) 29–30 (30) Late Medieval to post-Medieval periods, Scotland (NHM)
56. Poundbury 97–109 (106) 46–52 (47) Late Roman period, Southwest England (NHM)
57. Spitalfields-1 122–135 (121) 104–113 (106) Mid-Victorian, London (NHM)
58. Spitalfields-2 73–74 (75) 17–19 (35) Pre-17th century, London (UC)
North Africans
59. Naqada 82–87 (57) 89–93 (39) Predynastic Egypt, ca. 5,000–4,000 BP (UC)
60. Gizeh 122–125 (91) 46–51 (32) 26th–30th Dynasty, Egypt, 664–343 BC (UC)
61. Kerma 114–132 (58) 79–92 (51) 12th–13th Dynasty of Nubia (UC)
62. Nubia 86–92 (39) 42–47 (9) Early Christian or Christian date Nubia (UC)
Subsaharan Africans
63. Somalia 58–64 (53) 10–12 (5) Erigavo District, Ogaden Somali (US)
64. Nigeria-1 74–83 (72) 65–76 (53) Ibo tribe (NHM, UC)
65. Nigeria-2 73–80 (17) 46–53 (7) Ashanti tribe (NHM, UC)
66. Gabon 82–86 (47) 55–57 (36) Fernand Vaz River (NHM, NMNH)
67. Tanzania 69–75 (54) 20–25 (17) Haya tribe, Musira Island, Lake Victoria (UC, NHM)
68. Kenya 71–82 (31) 55–63 (10) Bantu-speaking people from Kenya (UC, NHM)
69. South Africa 100–109 (53) 21–25 (8) Zulu and once called Kaffir tribes (UC, NHM, AMNH)
70. Khoisans 43–36 (28) 17–22 (13) Bushmans and Hottentots (NHM, UC, AMNH)


Fig. 2. Two-dimensional scattergrams drawn by using first-second (a), second-third (b), and third-fourth (c) principal coordinates. Numbers correspond to sample numbers in Table 1


Useful info for reference!

Genes, peoples, and languages, a paper by Cavalli Sforza.

Genes, peoples, and languages
Department of Genetics, School of Medicine, Stanford University, Stanford, CA 94305-5120

The genetic history of a group of populations is usually analyzed by reconstructing a tree of their origins. Reliability of the reconstruction depends on the validity of the hypothesis that genetic differentiation of the populations is mostly due to population fissions followed by independent evolution. If necessary, adjustment for major population admixtures can be made. Dating the fissions requires comparisons with paleoanthropological and paleontological dates, which are few and uncertain. A method of absolute genetic dating recently introduced uses mutation rates as molecular clocks; it was applied to human evolution using microsatellites, which have a sufficiently high mutation rate. Results are comparable with those of other methods and agree with a recent expansion of modern humans from Africa. An alternative method of analysis, useful when there is adequate geographic coverage of regions, is the geographic study of frequencies of alleles or haplotypes. As in the case of trees, it is necessary to summarize data from many loci for conclusions to be acceptable. Results must be independent from the loci used. Multivariate analyses like principal components or multidimensional scaling reveal a number of hidden patterns and evaluate their relative importance. Most patterns found in the analysis of human living populations are likely to be consequences of demographic expansions, determined by technological developments affecting food availability, transportation, or military power. During such expansions, both genes and languages are spread to potentially vast areas. In principle, this tends to create a correlation between the respective evolutionary trees. The correlation is usually positive and often remarkably high. It can be decreased or hidden by phenomena of language replacement and also of gene replacement, usually partial, due to gene flow.

Which contains the

One reasonable hypothesis is that the genetic distance between Asia and Africa is shorter than that between Africa and the other continents in Table 1 because both Africans and Asians contributed to the settlement of Europe, which began about 40,000 years ago. It seems very reasonable to assume that both continents nearest to Europe contributed to its settlement, even if perhaps at different times and maybe repeatedly. It is reassuring that the analysis of other markers also consistently gives the same results in this case. Moreover, a specific evolutionary model tested, i.e., that Europe is formed by contributions from Asia and Africa, fits the distance matrix perfectly (6). In this simplified model, the migrations postulated to have populated Europe are estimated to have occurred at an early date (30,000 years ago), but it is impossible to distinguish, on the basis of these data, this model from that of several migrations at different times. The overall contributions from Asia and Africa were estimated to be around two-thirds and one-third, respectively.

Which doesn’t seem to fit the mt/Y DNA patterns, although to be fair L mt types don’t seem to thrive in a cold climate. Since he gives a 146,000 ya date for the first migration out of Africa, this second wave of expansion could have been a very long time ago. Possibly a double OOA might explain the total failure of Y chr dates to tally with the mt DNA expansion dates.

The first estimate gave a separation time of the first migrants out of Africa of 146,000 years ago, very close to the date obtained with the mtDNA full sequence. This was based on results with 30 microsatellites (5). More recent results (L. Jin, unpublished work) with 100 microsatellites gave an earlier date.

Also more humourously, but unlikely..

The Ethiopians genotype is more than 50% African. It is difficult to say if they originated in Arabia and are therefore Caucasoids who, like Lapps, had substantial gene flow after they migrated to East Africa, or if they originated in Africa and had substantial gene flow from Arabia, but not enough to pass the 50% mark.

I think the ‘ mixed expansion south from Egypt with some later Neolithic Arabian farmer’ is a more likely scenario.

I’ll admit to not reading the whole thing before posting it. I have a rotten headache and the kids are playing up. I’ll read it tomorrow.

And having had another look..

There’s this interesting map showing patterns of variation in Europe.

FIG. 2. Hidden patterns in the geography of Europe shown by the first five principal components, explaining respectively 28%, 22%, 11%, 7%, and 5% of the total genetic variation for 95 classical polymorphisms (1, 13, 14).



The first component is almost superimposable to the archaeological dates of the spread of farming from the Middle East between 10,000 and 6,000 years ago.




 The second principal component parallels a probable spread of Uralic people and/or languages to the northeast of Europe.




The third is very similar to the spread of pastoral nomads (and their successors) who domesticated the horse in the steppe towards the end of the farming expansion, and are believed by some archaeologists and linguists to have spread most Indo-European languages to Europe.



The fourth is strongly reminiscent of Greek colonization in the first millennium B.C.



 The fifth corresponds to the progressive retreat of the boundary of the Basque language. Basques have retained, in addition to their language, believed to be descended from an original language spoken in Europe, some of their original genetic characteristics. (From ref. 1, with permission of Princeton University Press, modified.)