November 2, 2015

Algerian complex genetics


This is a rather interesting study that deals with the genetics of the Republic of Algeria, with several new samples.


Asmahan Bekada, Lara R. Arauna et al. Genetic Heterogeneity in Algerian Human Populations. PLoS ONE 2015. Open accessLINK [doi:10.1371/journal.pone.0138453]

Abstract

The demographic history of human populations in North Africa has been characterized by complex processes of admixture and isolation that have modeled its current gene pool. Diverse genetic ancestral components with different origins (autochthonous, European, Middle Eastern, and sub-Saharan) and genetic heterogeneity in the region have been described. In this complex genetic landscape, Algeria, the largest country in Africa, has been poorly covered, with most of the studies using a single Algerian sample. In order to evaluate the genetic heterogeneity of Algeria, Y-chromosome, mtDNA and autosomal genome-wide makers have been analyzed in several Berber- and Arab-speaking groups. Our results show that the genetic heterogeneity found in Algeria is not correlated with geography or linguistics, challenging the idea of Berber groups being genetically isolated and Arab groups open to gene flow. In addition, we have found that external sources of gene flow into North Africa have been carried more often by females than males, while the North African autochthonous component is more frequent in paternally transmitted genome regions. Our results highlight the different demographic history revealed by different markers and urge to be cautious when deriving general conclusions from partial genomic information or from single samples as representatives of the total population of a region.


Y-DNA frequencies


Supplementary Table 2: Y chromosome haplogroup frequencies among the studied populations (% in parentheses)







Population Algiers1 Oran1 Reguibate1 Zenata1 Mozabite2 Oran3 Algiers4 Tizi Ouzou4
Abreviations ALG1 ORN1 RGB ZNT MZB ORN2 ALG2 TZO
Number of individuals 26 80 60 35 20 102 35 19
A -M91 (-) 1 (1.25) (-) (-) (-) (-) (-) (-)
C-M216 (-) 1 (1.25) (-) (-) (-) (-) (-) (-)
E1a-M33 1 (3.84) (-) (-) 1 (2.86) (-) (-) 1 (2.86) (-)
E1b1a-M2 (-) 8 (10) 2 (3.33) 8 (22.86) 2 (10) 8 (7.84) (-) (-)
E1b1b1a-M78 4 (15.38) 2 (2.50) (-) 1 (2.86) (-) 6 (5.88) 4 (11.43) (-)
E1b1b1b -M81 14 (53.85) 33 (41.25) 48 (80) 17 (48.57) 16 (80) 46 (45.10) 14 (40) 9 (47.37)
E1b1b1-M35 (-) 3 (3.75) 3 (5) (-) (-) (-) 1 (2.86) 2 (10.53)
E2 -M75 (-) 1 (1.25) (-) (-) (-) (-) (-) (-)
F -M89 (xJ, K, Q, R1) 2 (7.69) 4 (5) 1 (1.67) (-) (-) (-) 4 (11.43) 2 (10.53)
J -M304 (xJ2) 5 (19.23) 18 (22.50) 6 (10) 4 (11.43) (-) 23 (22.55) 8 (22.86) 3 (15.79)
J2 -M172 (-) 1 (1.25) (-) (-) (-) 5 (4.90) 2 (5.71) (-)
K -M9 (-) (-) (-) (-) (-) (-) 1 (2.86) (-)
Q -M242 (-) 2 (2.50) (-) 1 (2.86) (-) 1 (0.98) (-) (-)
R1 -M173 (-) 6 (7.50) (-) 3 (8.57) 2 (10) 13 (12.75) (-) 3 (15.79)









Y Haplogroup Diversity GD (h +/- sd) 0.6677 +/- 0.0806 0.7674 +/- 0.0356 0.3520 +/- 0.0757 0.7092 +/- 0.0625 0.3579 +/- 0.1266 0.7245 +/- 0.0325 0.7782 +/- 0.0499 0.7427 +/- 0.0831
1 Present study







2 Shi et al. 2010







3 Robino et al. 2008







4 Arredi et al. 2004










The most common lineage is E1b-M81, which is centered around Morocco and has a mostly NW African distribution. The Reguibate sample (Arabic speakers from near Southern Morocco and West Sahara) shows extremely high frequencies (80%) of it. This is also true of the Mozabites. Otherwise the frequencies range between 40% and 54%.

Tropical African lineages are mostly represented by E1b-M2, which peaks among the Zenata Berbers of the Southern Atlas and Northern Sahara but has also some notable presence in Oran, Mozabites (North Sahara) and Reguibate (West Sahara). However these lineages are nearly absent in the Northeast Kabyle Berbers (Tizi Ouzu) and only have a token presence in Algiers (E1a). 

E1b-M78, a lineage centered in NE Africa, seems to peak in Algiers, with low frequencies in Oran and effectively absent in other populations. 

J1, presumably the same as J(xJ2), is strongest in the coast (Algiers, Oran) but has significant frequencies in other populations (excepted Mozabites). 

J2, although quite rare, is worth mentioning because its presence may indicate areas of true Arabic settlement (of course J1 is more common in Arabia but it is unthinkable that one goes without the other in such a recent time frame). It seems that Oran has the strongest such settlement, although some is also apparent in Algiers.

R1 peaks among Kabyles (16%) and is also present in Oran and among the Mozabite and Zenata Berbers. Sadly it is not analyzed what fraction of it is R1b-M412 (Western European) or R1b-V88 (Afro-Mediterranean), as both lineages have been detected in North Africa in previous studies but almost certainly have different histories. 

Other F is quite intriguing. The few Q and K* individuals are within expectations (at least my expectations) but there are a lot of F* people, notably in Kabyle and Algiers that are most intriguing. Are they within haplogroup G or is it something else? G reaches almost 10% in Egypt but previous studies had not found more than 6% in NW Africa (Bouhria Berbers, see here).

Update (Nov 4): Chris makes a very interesting suggestion in the comments section about all this F*: what if it is (partly or in full) haplogroup I, a typical European Y-DNA lineage that is clearly rooted in the Paleolithic of the region? The lineage has been documented in ancient Berbers from Canary Islands and, for what Chris says, also in Sudan. It would make perfect sense if it was also present among modern NW Africans, being consistent with other genetics that seem to originate in Paleolithic Europe (~30% of mtDNA, a good share of autosomal DNA, maybe also part of the Y-DNA R).



Mozabites are close to "pure North Africans"

Autosomal analysis shows that this Berber population of the Algerian Atlas has the lowest range of admixture form any external source, be it Europe, West Asia or Tropical Africa. Some individuals appear extremely unadmixed.


Fig 3. Plots for the analysis of genome-wide SNPs.
PC analysis (upper figures) based on autosomal data, and X-chromosome SNPs. ADMIXTURE proportions (bottom figures) at k = 2,3, and 4 based on autosomal data and X-chromosome SNPs. Algeria, stands for general Algerian sample [3]; Mozabite, stands for the Algerian Berber Mozabites [32]; and Zenata, stands for Algerian Berber Zenata (present study).



X-chromosome conundrum

It is not common that genetic studies analyze the X-chromosome. A reason is probably that its interpretation can be confusing. Intuitively it seems true that the X chromosome is passed down by a mostly female line but this is not really correct, as (ignoring partial recombination) a man can have an X chromosome from either the maternal grandfather or grandmother, while a woman will have one from her father and another from the mother. Ironically only a woman's father-inherited X-chromosome can be automatically traced to a woman two generations back: that of the paternal grandmother. Complicated, right?

As probably apparent in fig. 3 above but made more clear in fig. 4 below, the study detected differences in autosomal (overall) ancestry and X-chromosome one.


Fig 4. Correlation plots of the ancestry proportions at k = 4 in the ADMIXTURE analysis comparing autosomes and X-chromosome SNPs.
North African, sub-Saharan, Middle Eastern, and European ancestry proportions are shown in different plots. Solid black lines represent linear correlations between autosomal and X-chromosome components.


The authors interpret these results as indicating female bias in the European and West Asian components. This may be true at least in the European case because it correlates well with the differential between European mtDNA (~30%) and Y-DNA (<10%), which suggests that European ancestry used to be more important in the past and that male-biased migrations (Capsian culture is probably one of the culprits) altered this. 

But is it also true for the West Asian ancestry? I can't say, really. I remember a study from a decade ago (don't have the reference right now, sorry) or so that showed that in a Colombian coastal town, X-chromosome ancestry was almost only European, while mtDNA was instead almost exclusively Native American, and that it should be interpreted as continuous influx of men from Europe, marrying local women, who managed to retain, generation after generation, the aboriginal mtDNA (which does never leave the strict maternal line) but not the X-chromosome line, once and again altered by male immigrants. 

I don't really dare to subscribe the authors' interpretation without a more nuanced analysis, analysis that I don't feel able to perform myself at the moment either. If they are correct, anyhow, it means that there were important male-biased demographic expansions of African specific origin, either in NW Africa itself (what could well be supported by the vigor of E1b-M81) or in NE Africa prior to migration to the West within Capsian. Or both. 


Mitochondrial DNA data

In case anyone wants to try their luck at this complicated analysis (North Africans are indeed a complex and most intriguing population), I'm adding here the raw mtDNA table:

Supplementary Table 5: mtDNA haplogroup frequencies (%) distribution among Algerian populations





Populations Algiers Oran Zenata Reguibate Oran (Bekada et al. 2013) Mozabite (Corte-Real et al. 1996)
Abbreviation ALG ORN1 ZNT RGB ORN2 MZB
Number of samples 62 93 73 108 240 85
H/HV 19.35 35.48 12.33 30.56 30.83 23.53
HV0 4.84 2.15 5.48 6.48 3.75 8.24
I 1.61 - 1.37 - 0.83 -
J (16069 16126) 14.52 3.23 2.74 0.93 3.33 3.53
K (16224 16311) - 4.30 4.11 3.70 1.67 -
L - - - 0.93 - -
L0 1.61 3.23 1.37 - 0.42 -
L1b 1.61 2.15 9.59 6.48 3.75 -
L1c - - 1.37 0.93 0.83 -
L2 - - 5.48 4.63 0.83 -
L2a 9.68 5.38 15.07 3.70 5.42 5.88
L2b 1.61 2.15 5.48 - 0.42 1.18
L2c1 - - 1.37 - 1.25 -
L2d - - - 1.85 - -
L2e - 1.08 - - - -
L3b 1.61 3.23 2.74 3.70 1.67 2.35
L3b/d - - 4.11 - - 1.18
L3d - - 4.11 - 1.25 -
L3e1 1.61 - - - 0.42 -
L3e2 4.84 - 5.48 - 0.83 2.35
L3e3 1.61 - - - - -
L3e5 11.29 - - - 0.42 -
L3f - 4.30 8.22 3.70 2.08 -
L3h1b1a 1.61 - 1.37 - - -
L4b2 - - - - 0.42 -
M1 3.23 5.38 - 1.85 7.08 4.71
N 1.61 1.08 - 0.93 0.42 -
R - - - 0.93 - -
R0a - - - 0.93 1.67 -
R0a1a - - - 8.33 - -
T* - - - 0.93 1.67 -
T1a 1.61 2.15 2.74 - 3.33 4.71
T2 - 1.08 - 0.93 0.42 -
T2b - - 2.74 - 2.92 -
T2c - - - - 0.83 -
U - 1.08 - 0.93 0.42 -
U1 - 1.08 - 0.93 0.83 -
U3 - 1.08 - - 1.25 10.59
U4 1.61 - - - 1.67 1.18
U5 - - - - 0.42 -
U5a 1.61 3.23 - - 1.67 -
U5b 1.61 1.08 - 2.78 0.42 -
U6a - 4.30 - 7.41 6.67 -
U6a1a - 1.08 - - - 12.94
U6a1a1 - 3.23 - 3.70 - 14.12
U6a1b - 1.08 - - - 1.18
U6a5 - - - - 0.83 -
U6c - - 1.37 - 0.83 -
U8b1 - 1.08 - - - 2.35
V - - - - 3.75 -
V7a - 1.08 - 1.85 - -
W 3.23 1.08 - - 1.25 -
X 8.06 2.15 - - - -
X2 - 1.08 1.37 - 1.25 -
mtDNA haplogroup diversity (h+-sd) 0.9175 +/- 0.0174 0.8630 +/- 0.0325 0.9376 +/- 0.0117 0.8823 +/- 0.0236 0.8853 +/- 0.0166 0.8891 +/- 0.0169
 


Good luck (and feed me back if you have some idea).

20 comments:

  1. Very interesting, thanks for sharing. C-M216 is a very strange one. The F-M89(xJ, K, Q, R1) could be G, however why not haplogroup I? [already found in modern-day Sudanese and in neolithic Guanche mummies]? Or even H - if something as unusual as C-M216 can turn up then why not? If the 'F' turned out to be 'I' then that would be interesting, given the presence of 'I' in Sardinia and Sudan..

    ReplyDelete
    Replies
    1. Very good point re. K* being maybe I. I'll amend the text to include that possibility because it is a serious one and one that may relate to the European Paleolithic component, so obvious in mtDNA (and also in autosomal DNA).

      As for C, it's just n=1, i.e. an erratic, so it doesn't have the same weight. However it could well be C-V20, the same haplogroup of La Braña and the only European-specific (or West Eurasian) branch of C. However it's not impossible that it could have a more recent West or Central Asian origin related to relationships with Turkey and in general the Asian Muslim World, after all it's found in a coastal city.

      Delete
  2. This comment has been removed by a blog administrator.

    ReplyDelete
    Replies
    1. ^^ Banned long ago (go read some other blog).

      Delete
  3. can give us conclusion that who's the majority are the arabic or the beberes
    and where is the biggest arab's settelement in algeria

    ReplyDelete
    Replies
    1. There's no apparent "Arab" genetic signature anywhere in North Africa: all are essentially Berbers, just that many have lost language and identity and, often, behave in a more cosmopolitan way therefore.

      However, if you want to threat in the blurry details, I said in the article: "J2, although quite rare, is worth mentioning because its presence may indicate areas of true Arabic settlement". Y-DNA J2 is only found in some samples (but not others) of Oran and Algiers, and at low frequencies in any cases.

      It does not need to mean "Arab" anyhow: Phoenicians particularly could have left a similar signature but in any case Y-DNA J2 is quite clearly in Africa, be it Algeria or Ethiopia, an unmistakable Semitic marker, while J1 almost certainly has older roots in Africa, probably from the Paleolithic in the Nile basin.

      "where is the biggest arab's settelement in algeria"

      It does not exist in any obvious way although some urban populations (Oran, Algiers) could well be somewhat admixed with Arabs (or Phoenicians, etc.), while Kabylia or the interior carry no such Semitic signature, not even at low frequencies (at least by this study, included the many earlier samples recycled in it). All North Africans are in essence pre-Semitic, i.e. "Berber" (or Ancient Egyptian in the case of Egypt, Nubian in Sudan, etc.)

      This is something we seem to find everywhere (also in Europe, Asia, etc.): that, while hunter-gatherers and farmers may have moved around quite a bit, replacing (never 100%) pre-existent populations, once warrior classes (aristocrats) came into the equation with the Metal Ages, the process of ethnogenesis becomes one of conquest and assimilation and only punctually of settlement. It is only in the Modern Age when colonization by settlement becomes again a major process, reflecting surely the loss of power of warrior aristocracies and the mass displacements caused by industrialization very particularly, accompanied by the crystallization of concepts that were much blurrier earlier like ethnic nationalism and quite notably racism.

      Delete
    2. PS- Maybe better than "industrialization" I should have said "capitalism", because prior to industrialization agrarian capitalism was already pushing many people to migrate, notably in Great Britain. Arguably just a detail but maybe worth considering anyhow, more so when we see many people that feel compelled to migrate today, not so much from industrial areas but rather the underdeveloped areas also subject to the tensions caused by capitalism, largely in agrarian form, which destroys jobs and subsistence opportunities in favor of profit.

      Delete
    3. thank you for the explanations

      Delete
  4. The interesting thing to me is that the indigenous Berber component appears to be around 25% Tropical African and 75 Eurasian. Formerly, it was assumes that the Tropical African ancestry in Berbers was solely due to Neolithic migrations or slavery, but that evidently can't be the case, right?

    ReplyDelete
    Replies
    1. Also interesting is that the component is shared by Palestinians until it diverges into a presumably Middle Eastern and the North African one. Do you think its possible that there's an Arabian component of prominent Tropical origin that is ancestral to Arabs and Berbers? Or am I oversimplifying it?

      Delete
    2. Well, my best guess (since long ago) for the formation of the North Africa (Berber or also Arabo-Berber, which only has a very minor Arab element) is as follows:

      1. Aterian early component (a local branch of the migrations leading to the Out of Africa one). This seems very minimal at best but IMO can be still detected in South Moroccans (see: http://forwhattheywereweare.blogspot.com.es/2011/12/north-african-genetics-through-prism-of.html). Some African-specific lineages may originate in this layer, for example the very deep Y-DNA A0, present in Mozabites but otherwise only, also very rarely, in West Africa, or some NW Africa-centered L(xM,N) matrilineages like L3k (if my memory is correct).

      2. Upper Paleolithic component, which is probably from Europe ("Cro-Magnon") origin in full or at least in a very large fraction, corresponding to the Iberomaurusian or Oranian cultural layer, which seems quite clearly related to Iberian Solutrean. This would include mtDNA lineages H (H*, H1, H3, H4 and H7) and possibly also V and even U6. On the Y-DNA side the impact is very eroded and would correspond at least to Y-DNA I (now rare but relatively common among ancient Guanches).

      My greatest uncertainty here relates to mtDNA U6 and Y-DNA E1b-M81, which might have arrived via an archaeologically "invisible" layer from NE Africa. The problem is that we don't know of any archaeological culture between Aterian and Oranian, so very unclear, really.

      3. The Capsian layer which is Epipaleolithic/Mesolithic but also extends into Neolithic and should be proto-Berber. Its origins, like everything Afroasiatic, seem to be in the Nile basin, which was already a mix of Eurasian and African genetics by then. E1b-M78 almost certainly arrived in this period, as did many mtDNA L(xM,N) linages. Again it is not clear yet how E1b-M81 arrived and expanded in the region: one possibility is that it could have arrived in this age and expanded via founder effect.

      As for Palestinian affinities, what they do there is to act as "control" for "West Asianness", just like Basques act for "Europeanness" and Yorubas for "Tropical Africanness". Saudis or Syrians would have worked pretty much the same.

      This affinity can be attributed probably to Neolithic elements, as well as more recent flows like Phoenicians and Arabs. Alternatively it may well be an effect of confusing the Mozabite endogamic component with the true NW African one. It would need testing, really, but I generally prefer to exclude or at least reduce the weight (number of individuals in the sample) for small endogamous populations, else the algorithm may well pick the wrong signal.

      Delete
    3. I'm specifically referring to the indigenous Berber component, without any of the recent ancestry from Europe, the Middle East, or Tropical Africa. When looking at the k = 2 results, you notice that the North Africans and Palestinian have some fairly substanial Tropical African ancestry. However, in k = 3, the Tropical African component disappears in Mozabites - which was formerly around 25%. The former two components are completely replaced by the yellow component in Mozabites, and the Tropical African component seems to decrease in similar proportions for the other populations with the arrival of the yellow component. This implies that the yellow component appears to be around 25% Tropical and 75% West Eurasian genetically in composition, correct? Meaning much of the Tropical African ancestry in Berbers cannot be due to recent input.

      Delete
    4. You mean the Mozabite component. The problem is how good are Mozabites, a distinct and endogamous community, at representing "indigenous Berber-ness", particularly with so few NW African samples involved.

      In my previously mentioned exercise (http://forwhattheywereweare.blogspot.com/2011/12/north-african-genetics-through-prism-of.html), I did not detect such a clear-cut difference, probably because I used many more samples, both North African and external controls, and Mozabites did not resolve to genetic homogeneity but expressed more than one component from K=2 to K=11, much as other NW Africans (but somewhat different). In that case I had problems with Tunisian Berbers (label "Tunisia"), whose endogamy seems even more extreme. This anomaly has arisen in other studies such as that of Henn (http://forwhattheywereweare.blogspot.com/2012/01/north-african-autosomal-genetics-again.html), so the Tunisian-specific components should be disregarded as noise.

      I strongly suggest that you take a look at those other two more extensive analyses because it will give you a counterpoint on which to balance your understanding of the matter. Algorithms, even the best ones, are just equations and, when something odd is in the data, their results can be easily distorted. This is particularly true when oddball endogamous populations are over-represented, be them very isolated Berber tribes, bottlenecked Jewish branches, endogamous sects like Druzes or low density populations such as most Finnics. The way to correct this bias is to keep the samples of these distorting populations small or just out (not always desirable though).

      In my own analysis (link above, twice), probably K=6 is quite a good level of analysis, and there it is not Mozabites but Sahrawis who best represent "indigenous NW Africanness" (cyan component), with the rest being more admixed with the European ("Spain", magenta) and West African ("Mandenka", yellow) components. Libyans are apart in that they have more of the West Asian ("Saudi", green) component, which is minor in the other North African samples (except Egyptians, which are even more Arab-like for this analysis).

      Seriously, for what you're talking about, my own mini-study is more nuanced (even if the colors are uglier) and it converges pretty nicely with that of Henn, which also used larger samples than the very limited Admixture test here. Please take a look.

      Delete
    5. Okay, now I see what you're talking about. I definitely do remember when the Tunisian sample kept fucking up in those analyses, but I hadn't seen them in awhile.

      Still, in the Saharawi samples, I notice the same thing about the Tropical African component. Once the Tunisian starts doing it own thing and stops fucking with the other results, it becomes clear the the Tropical African component disappears with the "indigenous Berber component". In k = 2, the Saharawi component in around 20-30% Tropical African depending on the analysis. And when the indigenous Berber component shows up by k = 4 and k = 5 and k = 8 on the second analysis, the Tropical African component is around less than 5%. Implying that the Indigenous Berber component itself is still around 25% Tropical African.

      Delete
    6. One of the things that you can see in my Dec-2011 mini-study is a table of Fst distances between components. For a reason I'll mention later, I decided to use the K=11 but guess that a smaller K-value would work to, with only minor differences. In the table it's apparent that the Sahrawi (Sah), Moroccan (Mor) and Mozabite (Moz) components seem all West Eurasian (clearly lower Fst scores with other West Eurasian components such as Arab or Iberian than with Mandenka, although the admixed Ethiopian component also scores very low). Ignoring the Tunisian "noise" components and internal North African affinities:

      MOR is closest to Ethiopian (0.071), Iberian (0.074) and Arab (0.081), what seems to fit with Capsian+Oranian+Neolithic affinities in this order. This North African specific component is the most related to others from outside the region.

      SAH is closest to Iberian (0.100), Ethiopian (0.104) and Arab (0.107), so maybe more like Oranian+Capsian+Neolithic but not too different from MOR, just most distant from all in general, more "drifted away", less connected or cosmopolitan that MOR through the passage of time.

      MOZ is even more "drifted away", more isolated, but still roughly in the West Eurasian group, with greatest affinity outside the region with Iberian (0.116), then Ethiopian (0.120) and then Arab (0.128).

      Notice please that the ETHiopian component is clearly a local "homogenized" mixture of West Eurasian plus Tropical African. Closest outsiders are Iberian (0.099) and Arab (0.101) but Mandenka in this case is not too distant either (0.115). At lower K-values Ethiopians show double affinities with West Eurasia and West Africa (probably just a proxy for East African aborigines, not directly contrasted, Dinka or Maasai might do) but at deep K-values they show off their long lived process of unique homogenization, which may well date from the Upper Paleolithic/LSA era. In Y-DNA NW Africans show strong affinities with Ethiopia and archaeologically it seems that Capsian culture, and hence the Afroasiatic (proto-Berber) layer, originated near the Nile, in Nubia AFAIK, although the deeper roots may be farther South well inside Sudan, even in South Sudan and South Ethiopia maybe, judging on linguistics.

      This issue of Ethiopian affinity may explain the initial appearance of Tropical African affinities and later its relative vanishing: it mostly comes from NE Africa (but south of Egypt proper).

      Delete
    7. The reason why I decided to operate with K=11 was because of the sudden pop-up of a most intriguing SMor or South Moroccan minor component. In the Fst table it has extreme distances to every other component, even the closest one, which is ETH (0.196), followed by Mandenka (0.206).

      With due caution, my interpretation is that it may well be a remnant of the Aterian layer, which is nowadays very minor across the board (~1% or even less), excepted the South Moroccan sample, which sports 14.4% of it. Again, when not properly detached, this component will push toward Tropical Africa with at least 50% of its weight. South Moroccans still have some 14% of "Mandenka" but that's quite less than it appears at lower K-values distorted by (a) the Ethiopian element (3%), (b) the Ethiopian affinity of the Berber components themselves before they show as distinct and (c) the "Aterian" or SMor component, which is clearly a very different thing but also very hard to detect (and today I still don't know if it may be some sort of artifact but I suspect it's not).

      It's a quite complex genetic landscape to be honest, but also a very interesting one. Hope you're enjoying the discovery of this very rich complexity.

      Delete
    8. PS- On the "Aterian" component, we can well understand it as a different "race" altogether, although not anymore found in isolation and hence hard to characterize. However in some anthropometric discussions I've stumbled more than once on the claim of a pseudo-Khoisan (sometimes said pseudo-Mongol) look characteristic of some peoples of that area. I suspect that it can be attributed to that component, which at 14% still may have some influence in phenotype or "looks" on semi-random basis.

      Delete
  5. As an Algerian born in Oran, I was wondering if you could translate this to a more layman speak (for somebody who was little to no background studying genetics)? So for example, would it be fair to say that a majority of my ancestry is likely to be native berber? Would you be able to break up my genetic background into percentages of different ethnicities based on what is statistically likely? Thank you!

    ReplyDelete
    Replies
    1. "I was wondering if you could translate this to a more layman speak"

      I cannot rewrite everything and I would't probably know how to, without betraying the truth, which is always complex. But feel free to ask and I'll try to clarify.

      "So for example, would it be fair to say that a majority of my ancestry is likely to be native berber?"

      Yes, absolutely.

      "So for example, would it be fair to say that a majority of my ancestry is likely to be native berber?"

      Take figure 3 above, focus on the bottom left graph, where it says K=4 ("autosomal", which refers to the nuclear chromosomes that do recombine, that are mixed every generation, the vast majority of the genome). That represents approximate ancestry in four colors:

      Yellow (Mozabite-like) is for sure Berber-specific, but probably not the only part.
      Green (Basque-like) is probably also Berber, from ancient interactions with SW Europe.
      Blue (Palestinian-like) can be both Arabic or Berber (due to ancient interactions via Egypt and Nubia)
      Gray (Yoruba-like) is confusing, the simplest interpretation is that it reflects recent trans-saharan inputs, maybe with the slave trade but in fact it can hide other stuff, such as more ancient proto-Berber (early North Afroasiatic) input from Nubia.

      This can be better seen maybe in the analysis I made back in 2011:
      → http://forwhattheywereweare.blogspot.com/2011/12/north-african-genetics-through-prism-of.html

      ... particularly this table

      There we see that, for example in Algeria (a non-specific sample), the main West African (Mandenka) component is only 7%, while the Ethiopian one is 6% and the Fula one is 2%. That's the ultra-saharan element I could detect in the generic Algeria sample. Total 14% (although the Ethiopian component is itself a 50/50 mix, part African, part West Asian, so if what you want to know how "black" the typical Algerian seems to be, the answer is 11%).

      Another interesting external fraction is the Arab one, which is only 10.6%. So the typical Algerian is about 11% Arab, all the rest must be attributed to local components (of West Eurasian affinity mostly), a 20% "Iberian", which should be also considered "Berber", as it must be quite old. Everything that is not Arab or West African is almost certainly "Berber" (or pre-Berber even).

      In brief, in my understanding, the typical Algerian is like:

      9% West African
      11% Arab
      80% Berber (at least, some of the other two components could also have been present among pre-Islamic Berbers)

      Notice that I include the Iberian component (probably Paleolithic in origin or at the very least pre-Islamic for the largest part) and the Ethiopian component within the Berber category because the Afroasiatic linguistic family (to which Berber belongs) and several associated genetic markers clearly expanded from the Nile Basin, probably in late Paleolithic times.

      Hope this helps.

      Delete
    2. There's a minor error above: the "ultra-saharan" component is 15% (not 14%) and therefore the strictly "black" element is rather 12% (not 11%).

      Delete

Please, be reasonably respectful when making comments. I do not tolerate in particular sexism, racism nor homophobia. Personal attacks, manipulation and trolling are also very much unwelcome here.The author reserves the right to delete any abusive comment.

Preliminary comment moderation is... OFF (keep it that way, please)