May 15, 2014

North African and West Asian affinity in Europe

Ryan mentioned this rather interesting study from a year ago on IBD trans-Mediterranean affinities of Europeans.

Laura R. Botigué et al., Gene flow from North Africa contributes to differential human genetic diversity in southern Europe. PNAS 2013. Freely accessible by now → LINK [doi:10.1073/pnas.1306223110]


Human genetic diversity in southern Europe is higher than in other regions of the continent. This difference has been attributed to postglacial expansions, the demic diffusion of agriculture from the Near East, and gene flow from Africa. Using SNP data from 2,099 individuals in 43 populations, we show that estimates of recent shared ancestry between Europe and Africa are substantially increased when gene flow from North Africans, rather than Sub-Saharan Africans, is considered. The gradient of North African ancestry accounts for previous observations of low levels of sharing with Sub-Saharan Africa and is independent of recent gene flow from the Near East. The source of genetic diversity in southern Europe has important biomedical implications; we find that most disease risk alleles from genome-wide association studies follow expected patterns of divergence between Europe and North Africa, with the principal exception of multiple sclerosis.

The most interesting section is surely the one titled Long identical-by-descent haplotypes. Here the authors use long IBD readings to estimate "recent" genetic flows. However they cannot discern the direction of these flows, i.e. flows from Europe to West Asia and North Africa will look exactly the same as the reverse ones.

From fig. 2:
Haplotype-based estimates of genetic sharing between Europe and Africa show a significant latitudinal gradient where the highest sharing is in the Iberian Peninsula. Genetic sharing between geographic regions is represented as a density map of WEA estimates for 30 European populations where haplotypes are IBD with (A) Sub-Saharan Africa [not shown here, as it is comparatively very small and clearly related to the other clines], (B) North Africa and (C) the Near East. The Canary Islands are shown in the Lower Left. (...)
It seems obvious that North African affinity is concentrated in Iberia, especially in the Western half, what is consistent with previous data, and that West Asian affinity is concentrated in SE Europe. The Iberian extension of this one may be partly related to North African affinity (or not), as North Africans also have some clear West Asian affinity (as should be apparent from the Canarian inset).

I insist that directionality of this affinity is not clear. In the case of West Asian one, it seems plausible that most of it is caused by Neolithic inflows into Europe but in the case of the North African affinity cline, it probably represents bidirectional flows, because previous mtDNA and autosomal data show also quite apparent Iberian influx into North Africa, although the reverse flow is also real.

I find interesting the low levels of West Asian IBD affinity among Basques when compared with estimates of ancestry by early European farmers (EEF, partly West Asian themselves). In the map above Basques score just like other Atlantic populations in this element, yet in the Lazaridis study (see also here and here), Basques score quite high in EEF ancestry, much like the French, which in this graph are clearly higher in "recent" West Asian affinity. That makes me suspect that confounding factors may be at play and reinforces the notion of taking autosomal DNA statistical analyses with some care and try to contrast different approaches before reaching to conclusions.

Also interesting is fig. 3, which pinpoints the specific North African (or Arabian) regions which may show the strongest IBD affinities for the various European regions:

Fig. 3.
Population-specific estimates of haplotype sharing (in centimorgans) between North Africa and Europe. Estimates of WEA (scaled by 100 for ease of presentation) between each European population (x axis) and each North African population and the Qatari are represented by colors and symbols. A substantial increase in haplotype sharing is detected between southwestern European populations and Maghrebi populations in comparison with the remainder of the European continent. The excess of sharing between the Near East and southern central and Eastern Europe is also noteworthy.

As expected,  NW Africa is the most common source-or-destination of Iberian long IBD affinities, instead Qatar or Egypt are most outstanding regarding Italy and SE Europe, what underlines that (North) African genetics in Europe arrived mostly via West Asia (Neolithic), with the notorious Iberian exception.


  1. I think this supports your suggestion of an early Neolithic origin for Vasconic languages via the Danube. These IBD affinities would be explained by groups like the Tartessians and Cardial Ware Pottery groups having greater North African and Near Eastern affinities (respectively). Both of which have been suggested elsewhere before.

    1. My hypothesis is via both the Danube and the Mediterranean. Both Impressed-Cardial and Painted-Linear pottery areas emanate from the same Thessalian Neolithic (Otzaki and pre-Sesklo respectively), even if this eventually adopts the Painted style.

      The question is that Vasconic should not be assumed to mean just Basque and Basques, but also many other attested or suspected languages of the past like Iberian, paleo-Sardinian or Ligurian in the Mediterranean zone, and a lot of Vasconic (not exactly Basque) substrate.

      As I understand it, Basque genesis in the Neolithic implies important Cardial-related influence and having the most direct Vasconic evidence in Iberian (because it was written and survived to the proto-historical period), strongly suggests that there is a Mediterranean link. But even more: if paleo-Sardinian is Vasconic as Blasco Ferrer thinks (and I find plausible for those and other reasons such as similitudes in some traditions like carnivals or the presence of the "Sardinian" clade of I as only meaningful non-R1b patrilineage among Basques), then Cardium-Impressed should be Vasconic. There's no Danubian influence south of the Loire. Instead Cardium-like influence reached as far North as the Rhine (La Hoguette). Also Cardium was in general more integrative of whatever aboriginal peoples it found in its way, judging on the archaeology, than what most of the Painted and Linear pottery waves surely were. So you can perfectly end up with populations like Basques that probably have important aboriginal HG ancestry but speak the Cardium culture language.

      In fact if anything would be less certain, it'd be that the Painted-Linear wave was Vasconic. But, on one side, both stem from the same specific small region: Thessaly, so even if they began with some cultural or ethnic differences, surely they ended up speaking the same language before expansion, just because of intense contact. On the other side, one of the areas with greatest (or at least best studied) Vasconic influences is Northern Europe (Germanic seems to have a lot of Vasconic elements, although I guess that they can always be loans rather than substrate, and so does the toponymy of Central Europe).

      So my interpretation (always tentative, of course) is that Vasconic was the language family of European Neolithic and that little survived (linguistically) to its dynamic advance by both routes and later also via Atlantic Megalithism.

      About Tartessians, I really don't know what to think: the SW Iberian Bronze horizons that originated them are quite apparently intrusive and the language has yet to be satisfactorily interpreted. But it does not look like Berber or Afroasiatic either, so I'd rather suspect something like arriving from the Aegean or whatever. But with all kind of doubts. They did not need to cause a massive genetic impact anyhow: it was already the era of elitist conquests, so a relatively small number of warriors would do it if luck and alliances were on their side.

      The North African - Iberian genetic bidirectional flow is for me either Paleolithic (Solutrean-Oranian) or/and maybe Neolithic (Cardium "bounce" in North Morocco for example, or maybe the debated La Almagra style pottery, of unknown origins). I don't think it has anything to do with the proto-Tartessian intrusion among other reasons because the genetic impact reaches NW Iberia in full and after Neolithic/Megalithism, that area was already quite populated.

    2. Re: Tartessian - Berber may have been a pretty recent arrival in the area too. I don't think it's been very well established when exactly Berber arrived in NW Africa, or when Afroasiatic became the only language family there. For example, I doubt the Capsians were Afroasiatic speaking.

      Re: Paleosardinian - I do not think it is safe to assume linguistic continuity from the early Neolithic in Sardinia. My understanding was that the Nuragic civilization was Bell Beaker derived

      Re: Cardial - I thought the Cardial Pottery culture's roots were suspected to be in the Near East, migrating to Thessaly and then later expanding from there. Or is that out of favour now? As you said though, their ancestry would have become more and more diluted as they moved west. I only meant to bring them up in the context of the Near East IBD sequences though - I didn't mean to imply that they were responsible for the North African sequences.

      I don't really disagree with anything else here, but just to be clear, I'm speaking in the context of why the figures for the Basque sample are so low. It's a pretty striking difference isn't it.

    3. "I doubt the Capsians were Afroasiatic speaking."

      I don't: there's really no other possible time-frame. Another thing is how consolidated it was in each period (were there pockets of other locally older languages?) and, particularly, the consolidation of Berber as such, which may well be something of the historical or proto-historical period, as it seems "too recent", in relation with the formation of the Numid and Mauritanian realms.

      Whatever the case I see no particular reason to imagine a North African origin for the SW Iberian Bronze culture. Its origins are somehow related to the shift Los Millares → El Argar in the Southeast and some elements like triangular bronze knives in "commoner" graves in cist, suggest to me that it has a European origin. Triangular knives are common in the Bell Beaker, right? Also, as I have mentioned before, the North African elements in Iberia are by no means restricted to that area and seem much older (La Braña, some L3(xM,N) in Epipaleolithic Portugal), so I find extremely difficult to associate them with the proto-Tartessian horizons. I think that most of it is from the Solutrean-Oranian genesis in fact.

      "I do not think it is safe to assume linguistic continuity from the early Neolithic in Sardinia. My understanding was that the Nuragic civilization was Bell Beaker derived"...

      Actually the closest thing to a nuragh is a motilla (and vice versa). Its relation therefore seems to be with El Argar and the Levante Bronze of the Valencian Country (together proto-Iberian) and also with the Chalcolithic Iberian innovative fashion of burial tholos, whose kind of architecture was used for the nuraghe/motillas. However there is no particularly notable genetic relation between Iberia and Sardinia, where, even if the language could have shifted (???) the genetics are clearly older, as evidenced by their conservative affinity to Ötzi and other EEFs. I'd say it's difficult to argue for a language shift without at least some colonization, although it did happen indeed in Roman times.

      Anyhow the evidence for Vasconic influence seems to extend to peninsular Italy (Arona, Arno, Tiber ~ Iber, "lava" ~ labe (=oven, furnace), etc., even the Slovenian word karst is considered pre-IE and related to Basque harri = stone, Corsica ← Korsis ← Gorosti(-aga) (=holly tree)) and that's a major reason I suspect that Vasconic expanded with Neolithic, because there's no such strong Western influence in Italy later on, is it?

      Much less there's influence in the Balcans where some stuff at least (rivers Ibar, Hevros for example) suggest a (weaker but present) Vasconic substrate.

      And then we cannot really differentiate between Cardium and Danubian EEFs genetically: they were very much the same in this aspect and hence most likely the same "greater people".

      "I thought the Cardial Pottery culture's roots were suspected to be in the Near East"...

      Not at all. That's a fallacious map from Wikipedia which mixes apples and oranges. The first evidence of Cardium is found in the so-called pre-Sesklo pottery of Otzaki and some other Thessalian sites (simultaneous to the so-called proto-Sesklo one of Sesklo and such). From there it spread to Epirus, the Adriatic Balcans and Southern Italy, and from there it sailed westwards.

      It is true that in a late phase, Cardium pottery was adopted by the Biblos facies of the Amuq-Biblos culture but that's not the origin at all, just another destination (whose implications I don't dare to judge).

      "Or is that out of favour now?"

      It has never been "in favor", it's just a Wikipedian's mistake that has remained uncorrected for years.

    4. "Also, as I have mentioned before, the North African elements in Iberia are by no means restricted to that area and seem much older (La Braña, some L3(xM,N) in Epipaleolithic Portugal), so I find extremely difficult to associate them with the proto-Tartessian horizons. I think that most of it is from the Solutrean-Oranian genesis in fact. "

      I'm not disagree with that at all. Is there a reason that that influence should be so much lower among Basques than neighbouring groups though? I confess I've never visited Spain - how rugged is the terrain along the northern coast?

      Re: Bell Beakers - I'm pretty sure there were actual bell beakers excavated in the strata immediately prior to the first nuraghs. I would think that suggests at the very least a great deal of contact.

      Re: Basque words, I don't disagree necessarily, but I'm not sure one can distinguish between earlier Neolithic routes and later Bell Beaker influence in many cases. With respect to the Balkans though, good point.

    5. Asturian Solutrean is of Iberian roots, while Basque and Cantabrian ones are of French roots. However in Magdalenian, later on, Cantabria aligns with Asturias in the facies division. This is possibly one root of the Basque vs. Astur-Cantabrian differences, particularly for the African element. It's even possible that Cantabrians or Asturians are more Braña-like than Basques (or undefined "Spanish" from Valencia) - has anyone even checked?

      There are other possibilities, I guess but that's my main work hypothesis.

      "how rugged is the terrain along the northern coast?"

      A lot: the mountains practically blend with the sea. Google images for "Cantabrian coast". For the Romans all this was the Pyrenees and geologically it's not really different in fact: the Pyrenean chain does not go from sea to sea, as is said conventionally, but continues along the southern coast of the Bay of Biscay all the way to Galicia - just that modern geographers have divided it in three segments: Pyrenees proper, the lower (but equally rugged) Basque Mountains and the again very high Cantabrian Range. There are some flatter areas where population concentrates but it's very rugged in any case.

      And also the climate is more like Wales than what you imagine "Spain" to be (a bit warmer sure but similarly wet and green).

      The rugged geography is actually very common in all the Iberian peninsula (which is being slowly pushed northwards and slightly eastwards by Africa) but nowhere as in the North. This applies in general terms to all Mediterranean Europe (for the same chthonic reasons - i.e. the Alps and Pyrenees respond to the same geological forces, etc.)

      In the Paleolithic we can see several facies along this coastal strip and, as I said above, the cultural source of the Asturian and Basque ones are different, with Cantabria oscillating between the two. Even in the Neolithic, Basque one seems older (more open to Mediterranean inputs by both northern and southern routes), however there's no clear Basque specificness before the arrival of Urnfields, which cut the Atlantic from the Mediterranean as a wedge. Then again there's no clear Astur-Cantabrian cultural area either before the Bronze Age, when it becomes apparent. All it was just amorphous Megalithic area and the differences we see are rather coast (less developed, dolmens without corridor) vs Ebro valley (more developed, dolmens with corridor, also more clearly Mediterranean-influenced judging on skull metrics).

      "I'm pretty sure there were actual bell beakers excavated in the strata immediately prior to the first nuraghs. I would think that suggests at the very least a great deal of contact".

      The maps I've seen about BB in Sardinia show mostly limited extent (particularly the NW). I'm not saying that there is no relation but what is much more clear is the architectural and temporal relation with the SE Iberian "motillas", which are nearly the same thing. Even in BB, many groupings place Sardinia in th SW "province", so the Iberian/South French relationship is pretty much certain.

      "I'm not sure one can distinguish between earlier Neolithic routes and later Bell Beaker influence in many cases".

      Bell Beaker is not an independent phenomenon. In nearly all places it must be considered as a minority element (maybe a "sect" or "guild") inside a wider continuous cultural context. There's no distinct BB "culture" nor "ethnicity" that we can discern, just a network within older locally rooted cultural contexts. I just mentioned a most interesting ebook on the matter, for example. Also it's very plausible nowadays that the phenomenon originated in Iberia, even if in Central Europe it adopts burial forms that mimic yet invert the Corded Ware ones (suggesting IE continuity through reform).

    6. A post-statement on the "proto-Tartessian" Bronze Age SW Iberian horizons:

      A. Valera published this week an entry in which he evidences that ditched enclosures and dolmenism were abandoned in Alentejo several centuries earlier than this period:

      I therefore asked him for more info on the Copper-Bronze transition but he's not the talkative guy so he just said that megalithic burials were switched "by individual or multiple burials in cists, pits or hypogea". The cists are a shared element between this latest Copper and the Middle-to-Late Bronze, when the Alentejo adopts the Bronze and its cultural elements of the SW Iberian group (mostly burials in cists with a triangular knife, some "princely" burials of the grabsystem walled design).

      If so it's still possible that the Bronze horizons and hence Tartessian is a local development and not intrusive as I thought.

    7. Do you need a large demographic influence to leave behind a lot of toponyms though? I would think a lingua franca would be in a pretty good position to leave lasting names even if it had few native speakers. The Chinook Jargon in the Pacific Northwest would be a good recent example of that. Or all the Spanish names out here like Cortes Island, the Strait of Juan de Fuca, Quadra Island, Malaspina, Port Estevan, Galiano, Flores, Haro and Tofino. You're quite right that that wouldn't explain Sardinian though.

      Re: climate/geography on the north coast of Spain - mountainous, mild and damp? Sign me up lol. It took a quick look at Bilbao's climate to compare to Vancouver's, and it looks like it's something I'd be pretty familiar with. About 5 degrees warmer with wetter summers and drying winters. Seems alright.

    8. English is a lingua franca and we don't see it leaving many toponyms where it is not native or at the very least co-official for all practical purposes. Latin was a lingua franca and what toponyms has it leave in, say, Denmark or Hungary? Nope, I don't see it.

      Castilians were exploring and conquering half the world (the other half was for Portugal according to Tordesillas Treaty). Many of those places had native names but those who came behind the Castilians took the Spanish toponym for reason of cultural communion.

      I'm not sure what you have in mind but what you say about Castilian toponyms in areas of Castilian exploration and claim (and often temporary conquest) followed by someone else from the same area is just two waves of invaders from the same approx. homeland, who know each other and, even if they compete at times, agree in the bigger concept of shared expansionism. The same expansionist wave.

      Castilian was never a lingua franca incidentally (although there was in time of Columbus a Mediterranean Romance potpourri that was used as such).

      "Sign me up lol. It took a quick look at Bilbao's climate to compare to Vancouver's, and it looks like it's something I'd be pretty familiar with".

      There may be strong similitude I guess (although I thought that Vancouver was colder and our climate was more like Oregon's or North California maybe - never checked though). The reason is that the general oceanic currents' pattern is similar, although in North America it affects a much smaller strip of land because of the formidable barrier that the Rocky Mts. are. In Europe instead the Northern plains and the Mediterranean Sea act as conductors for those patterns inland, so the transition is much more gradual and those climates do exist in much wider areas at similar latitudes.

    9. The Dava River and Keszthely would be two Hungarian toponyms potentially received from Latin. I was going to suggest the Mura/Mur River (ie the Border River) but that could just as easily be some other Indoeuropean, Vasconic and Altaic etymologies that seem plausible too and I can't find any articles that actually discuss the origin of the Mura/Mur's name. Császár (Caeser) is an obvious one in Hungary too.

      A better example from my standpoint might actually be the Basque names in Newfoundland like Port au Choix (Portutxoa)and Port au Port (Ophor portu). Or all the from places from Africa to Indonesia with the word Bandar in them from Persian.

      Point taken though. I thought Bell Beakers had separate settlements though? I would think that if I were an invading interloper, and I wanted to an interpreter, or to find out about the local landscape, I'd want someone who spoke a language that was widely spread. It wouldn't necessarily be the toponyms the locals used, but perhaps the exonyms instead.

      Re: climate - Vancouver's pretty similar to Oregon. Just a bit wetter and colder, but not much. The Pacific Coastal Range more directly impinges on Vancouver so we get dumped on a bit more than they do. Between the Pacific Coastal Range and the Rocky Mountains there's a more arid area, particularly in southern BC. Osoyoos' climate is actually a bit drier than Madrid's, and it's summers a bit hotter. Looks like this by August: Then once you hit the Rockies it gets wet again.

    10. By "Rocky Mts." I meant the whole system of the North American Cordillera, although, of course the Rockies would be the definitive barrier. Here also smaller mountain ranges act as local, often quite radical barrier. Just crossing the Basque Range to the south and in winter it freezes ("Siberia-Gasteiz" they say to Vitoria-Gasteiz) and in summer the fields are yellow, something that never ever happens here. An even more dramatic change I experienced in Macedonia: I've passed from -24ºC (at night, winter) in Skopje to a pretty nice +9ºC in Thessaloniki in just a day. The sea is a great benefactor, more so when the currents bring the right kind of thermal correction.

      But regarding the wider view: in North America the warm currents only affect the narrow strip West of the mountains, while in Europe, because of plains and inner seas, they affect all the continent, decreasing only in a much more gradual manner.

      Anyhow, definitely Vancouver is colder than Bilbao: 2-5ºC for average temperatures depending on season. That sounds more like Wales or Bristol (I checked and Vancouver's temperatures are very similar to Bristol in fact).

      I had that idea before checking because my reference is the Mediterranean climate, which only exists in the Mediterranean basin and a handful of pockets through the World: parts of California, Chile and South Africa in essence. So if we are right north of the Mediterranean climate zone here, the equivalent should also be in North America what is right north of the Mediterranean pocket of California, i.e. North California or Oregon. I just checked Portland and it approximates Bilbao better, although it is a bit more extreme (hotter in summer and colder in winter). Actually Portland (45ºN) is still a bit to the North of Bilbao (43ºN), so I guess it compares better with Bordeaux.

    11. "I thought Bell Beakers had separate settlements though?"

      In most regions they did not. Mostly BB artifacts show up in locally rooted contexts. In the South-Western region they are invariably Megalithic and, in VNSP civilization (Zambujal and such), their artifacts become overwhelmingly present, while in other regions, even the nearby Alentejo, only show up scatteredly, but always in local traditional contexts (cultural continuity).

      This seems to be the general pattern but in Central Europe (Danubian region) it seems as if BB was more overwhelmingly influential, with specific burial traditions that mimic but also invert the Corded Ware pattern of gender-specific differences. When Bohemia was considered the main origin of BB, this was taken as reference (although it was obvious that there were major differences West and East of the Rhine), but now it seems more apparent that it was in fact Iberia the origin of the "fashion", so it is surely more like the exception.

      Regarding toponyms I still don't get your point. Just to mention that Dava does not sound Latin to me and in fact there are rivers with similar names in the Cantabrian strip (Deva, spelled Deba in Basque) in both the Basque Country and Asturias. The Basque Deba river is mentioned by some Roman geographer, possibly Herodotus, as border between the Caristii and the Varduli and even today it is the approximate border between the Biscayan and Gipuzkoan dialects of Basque (what has been argued to imply that dialects, at least in this case, reflect ancient tribal geography).

      The name of the river Deva has been used by partisan Indoeuropeanists to claim Celtic presence in the Basque area (as well as in the Cantabrian-Asturian one), however this form does not exist in Celtic nor Latin (although it's clearly pre-Roman in any case) being only real in the Indo-Aryan branch of IE, where it means "god", and in Slavic, where it means "maiden" or "virgin". Both branches are most unlikely to have ever been present in Western Europe so the real etymology of the name remains unclear.

      A Basque origin possibility that I just fathomed could be Ate-ba (under the gate or mountain pass) but it is as speculative as any other.

    12. With Dava at the very least the Magyars preserved the Latin form. Rome itself is an Etruscan name so cut me some slack here lol. :3 Alba as the Gaelic name for Scotland would be a better example of the impact of Latin outside Roman borders IMHO (and yah I realize that originally came from Greek and only entered Gaelic via Latin).

      Re: Climate - keep in mind that eastern Canada has the opposite going for it in terms of currents. Toronto is at 43º43' north, and London Ontario is actually south of 43º. Hudson's Bay and the Labrador Current don't do anyone any favours back there. The southernmost extent of non-Alpine permafrost in the entire world is actually in Northern Ontario at 50º N. Contrast that to the west coast, where Victoria is actually classified as cool Mediterranean under some sources, and where the Gary Oaks of northern California find their limit. Vancouver, Victoria and San Francisco have roughly the same average temperature in the summer. It's winter where the weather goes to complete crap.

      Re: Bristol - yah, similar in temperature. Precipitation is quite different. Vancouver is roughly twice as dry in summer and twice as wet in winter as Bristol, with Bilbao being roughly halfway between the two.

    13. "With Dava at the very least the Magyars preserved the Latin form"...

      I don't see how "dava" means anything in Latin, sorry.

      "keep in mind that eastern Canada has the opposite going for it in terms of currents."

      I'm aware. All the way down to Virginia gets a cold stream from Greenland. The same as in East Asia. East = cold, West = warm. All thanks to Earth's rotation.

      "Vancouver is roughly twice as dry in summer and twice as wet in winter as Bristol, with Bilbao being roughly halfway between the two".

      Does it rain more in Bristol than in Bilbao? I live with an Englishman (from London, it must be said) and he used to complain often about the rain here, explaining that England is not as rainy as the cliché suggests. It may only apply to the East though.

      OK. Just checked and it rains more in Bilbao than in Bristol, although quite close and similar patterns. We're not just slightly taller than the English, we also get to use umbrellas slightly more often and sail around most of the world slightly earlier. ;D

      What source are you using? I'm looking at Wikipedia, which has very complete climate tables for most cities.

    14. Dravus is the name the Romans called that river by (I may have omitted the R courtesy of a typo). The name likely has a deeper source, but it was transmitted via Latin to become Dravus today. A week point I know. There are some places with names that use terms borrowed into German from Latin though. Rózsadomb (Rosenhügel ie Rose Hill in German). Was Latin even the lingua franca when the Magyars arrived though?

      I was using Wikipedia. I was focusing more on the distribution of the rain over the year rather than the total amount though. Both Bilbao and Vancouver have rainier winters than Bristol. I was looking at the Long Ashton data - though when I look now it seems that Long Ashton gets a hell of a lot more rain than the weather station in downtown Bristol. 626.8mm for the Bristol Weather Station compred to 913.3mm at the Long Ashton station. London only gets half as much rain as much rain as Vancouver and Bilbao it seems.

      The big difference in precipitation between Bilbao and Vancouver seems to be that Vancouver's rain is much more highly concentrated in the winter (or at least non-summer) months, whereas Bilbao's precipitation is more evenly spread throughout the year.

      What's the term for adiabatic winds in Basque btw? We call them chinook winds here. Wiki just gives me the Spanish term (Viento del Sur).

    15. "I may have omitted the R courtesy of a typo".

      Twice?! In two successive posts with me replying on the matter? I must complain very seriously about your sloppiness. Think before you comment, please.

      Nothing to do with Deva then. And it does not mean anything in Latin either.

    16. "Both Bilbao and Vancouver have rainier winters than Bristol."

      Bilbao is slightly rainier than Bristol every single month of the year. Apparently in your area (Pacific Coast of North America) Winter/Summer changes are a tad more abrupt than in Europe.

      "whereas Bilbao's precipitation is more evenly spread throughout the year."

      Not just in Bilbao: all the Atlantic coast of Europe seems similar: it rains a lot in autumn, it rains a lot in winter, it rains in spring (a lot in April typically - Spanish saying: "Abril: aguas mil") and it rains in summer (quite concentrated in August normally: they are usually evening storms caused by daily overheating of the sea). Not sure exactly why these differences but the Pacific Ocean is much bigger and the Rockies must also exert an important influence of some sort (the Chinook winds, I guess).

      We do not have personal names for the winds, that's a Mediterranean thing. Most of the time it's NW or West winds from the sea, which tend to bring rain and storms (their influence varies depending on season because of the Azores-North Atlantic high-low pressure system). Sometimes South winds (ultimately from the Sahara) which bring heat and traditionally were considered to be able to cause temporary madness and NE winds (ultimately from Siberia), which bring sharp cold, frost and rarely snow. South wind is called "hego haizea", maybe a more popular name than the rest. We don't have any "Chinook winds" because we don't have any mountain range comparable to the Rockies in size (width especially) nor N-S orientation. Mountain ranges, especially the high young ones, in Europe tend to be oriented W-E because they are caused by Africa pushing northwards. There are exceptions but nothing like the Rockies. The ranges are rather related to the Mediterranean climate frontier, as they weaken the influence of the Sahara further North.

    17. Chinook is a Rockies <-> prairies thing. It's not a coast thing. Chinooks account for the sudden change in temperature seen in places like Calgary, Alberta.

      The Pacific coast, north of Portland, Oregon (approximately) is influenced by the Japanese Current. On the coast, the wind is quite constant and comes from the west. The climate between the coast, north of Portland, all the way to Alaska, is very different from that seen on the Prairies. It's known as the raincoast and you are right, it rains (and occasionally snows) almost every month of the year on the coast.

      In British Columbia, there are three major mountain ranges that separate the coast from the prairies:

      The Coast Range
      The Monashees
      The Kootenays
      The Rockies

      As a northern extension of the coast range, the St. Elias Range contains some of the highest mountains in North America.

    18. Yah sorry about that. I read it as Dava off a list of Latin place names in Pannonia and didn't notice the error until I went back to look at the list again. :/

      I don't think this is strictly a Pacific thing - from what I understand the Mediterranean dry summer / mild wet winter is the rarest precipitation pattern in the world. It only really extends from California to the south coast of BC in the north Pacific, where the subtropical anticyclone manages to extend its influence. Apparently the equivalent in the Atlantic is the Azores High. Perhaps its the Rockies that extent its influence north rather than east as the Azores High does with the Sahara.

    19. The areas of dry climate in places such as Victoria, BC, are a result of a rain shadow effect on the coast. The Okanagan also sees a rainshadow effect, because so much rain gets dumped in the coast range.

      I wouldn't say that Vancouver (BC) has a Mediterranean climate. It's a lot more like central Japan than the Mediterranean.

    20. Nobody is saying that Vancouver "has a Mediterranean climate". I say it's roughly like Bristol, which is about the same latitude and similar Western continental position. Japan is rather like the Eastern USA, not the West (because both get a cold current from the Arctic).

      What Ryan is saying is that it's more like Bilbao but I say not: Southern Oregon is like Bilbao climatically speaking. And neither is Mediterranean climate in any case: that's further south.

    21. Marnie - It's more of a general phenomenon called a Foehn wind though. It's caused by air travelling down a slope being heated adiabatically as the pressure increases. In the Rockies it's called a chinook. In the Polish Carpathians it's called a Halny. In Cantabria it's called the Viento del Sul. It's fogony in the Catalan Pyrenees. In Cascais it's the Nortada.

      Re: the raincoast - that effect isn't constant throughout though. The summer drought in Victoria is important enough to have a significant effect on the kind of flora that grows in the area though. The weather station in downtown Victoria actually experiences less precipitation than Barcelona (608mm in Victoria to 640mm in Barcelona). Compare that to Tofino a little ways up the coast where they get more than five times as much rain as Barcelona (3271mm of precip a year - ouch).

      Interesting discussion though. IIRC the foehm wins played a role in maintaining the Franco-Cantabrian refugium. Interesting too re: the genetic and cultural influences that are common to similar climatic zones as discussed earlier.

    22. I think that Viento Sur ("sul" is Portuguese), which is the same as our Hego Haizea, is caused by the Saharan high pressure center moving northwards. Basically the climate of Europe has, AFAIK, four centers of activity: three high pressures Sahara (hot, dry), Siberia (very cold, rather dry) and Azores (warm but humid) and one main low pressure focus in the North Atlantic (fresh to cold and very wet, usually associated with storms).

      I don't think that there is any mountain caused anomaly in the Cantabrian strip, other than generally keeping the Saharan influence a bit more fenced off. It is when the mountains can't hold the Saharan airmass when the Viento Sur happens and it gets really sunny and hot.

      "IIRC the foehm wins played a role in maintaining the Franco-Cantabrian refugium".

      Not sure why. I never thought it that way: it's just that it is more to the South and the West than other inhabited regions of Europe, so the weakened Gulf Stream and the Saharan influences kept it warmer and also wetter, even if not nearly as much as today. Further south it was much more forested (back then the Mediterranean basin was essentially a huge forest) so it was not as optimal for hunter-gatherers. The FCR was right in between those two areas: one often too cold to the North (Northeast) and another too forested to the South.

      Anyhow even in the LGM, the permaforst never went further south than Szeged (at low altitude), which is at 46ºN, so the FRC was still in the habitable zone (so to say) even in the worst of the Ice Age. However it's true that it was in that period when Mediterranean Iberia shows its greatest population densities and when the Oranian culture appears in NW Africa, owing largely to European migration. But it is also then when the FCR becomes the "heartland" of Paleolithic Europe, previously the epicenter was in Central Europe and it also moved northwards again in the Epipaleolithic.

      So in any case it must have enjoyed a relatively good climate, which I would say owes to both the Sahara (warmth) and the Atlantic Ocean (some warmth too but more so humidity). Where water is life exists.

    23. The Basque page for Foehn winds actually mentions the Hego Haizea as an example ( as well as a few other winds in the area. Interesting that the beliefs about the wind's effects in the Basque Country are the same as in southern Germany. More substrate influence? In any event, at least some of the wind's warm has to have come from the loss of elevation. Physics demands it. Could still be other factors contributing of course (like the Sahara).

      Here's a photo of a foehn wind coming down of the Cantabrian mountains if you're interested: You can see the droplets and crystals sublimating and the cloud dissipating as a result as it travels down the slope. Pretty neat to see in action.

      Re: the LGM - Foehn winds also come off the ice sheet itself from what I've read. So it kept areas close to the glaciers relatively more habitable than you might expect.

      The name "Chinook" literally means "snow-eater" which I think is rather apt.

    24. No matter how much I think of it, I do not see the South Wind here to be Foehn-like at all. Notice that Foehn implies rains on the other side of the mountains and here rains almost invariably come from the Ocean (NW winds) and almost never from the South. If what the Basque Wikipedia article says would be true, then we'd see rains in Araba or Castile and "drought" in the coast but that never happens because south winds actually come from the Sahara and the Mediterranean-Continental climate of inland Iberia does not help at all with humidity.

      It is a very different case to what happens in the Alps, because North Italy is quite humid (typically it is full of mist in winter and it is quite green for a Mediterranean climate area, possibly because it is protected from direct Saharan influence by the Apennines), so I can understand that this brings rain clouds northwards. But Iberia is very different, much more like Turkey, with a quite dry interior that gets rains almost only from the Ocean.

      Notice also that the North Iberian Plateau is very high, some 700 m. above sea level, a "little Tibet" of sorts, so there's no such big height difference when arriving to the mountains, much less in the lower Basque Mountains. Only in case of winds blowing inland from Portugal and then turning North I can imagine that kind of phenomenon. But that's very rare.

    25. In the Spanish Wikipedia, when talking of Viento Sur in Cantabria they mention two cases:

      1. More common in winter: south wind usually preceding cold winds from the North, suddenly rising temperatures by as much as 10ºC.
      2. Rarer but happens in late summer too: in this case the South Wind blocks the oceanic breeze, causing what we call "bochorno" (unbearable heat, no wind), which can get really hot, almost Saharan, although it seldom lasts more than few days.

      The Foehn effect is mentioned just as anecdote: typical "hat" clouds on top of some mountains that remain there for days but with no relationship with the hot dry Viento Sur. When Foehn is mentioned in Spain, the most notorious effects happen in Almería province, where the humidity from Guadalquivir valley is drained by the mountains, so it is largely a desert (your typical Spaghetti Western scenario). It also happens in the East and in the Ebro Valley and in this cases, the mountains deprive those areas from the rains that come from the Ocean (not the other way around).

    26. Notice that on the Spanish foehn effect page the example photo is from la sierra del Escudo de Cabuérniga though.

      There seems to be a lot of imprecise use of the term in these articles though. Some refer to Santa Ana winds in California as Foehn, some refer to them as katabic winds, and some both. In any event, any time air travels down a slope it's going to warm up. Dry air warms at about 9ºC per 1000m, so dropping from a 700m high plateau to sea level will warm the air by about 6ºC. A rainshadow effect will warm it more of course thanks to the heat of condensation.

      The ghibli in Libya and the berg winds in South Africa both come from hot dry plateaus (the Sahara and the Kalahari respectively) and both seem to be referred to as Foehn. Part of why I went with "adiabatic winds" originally as the term. Maybe someone with more expertise in the field can comment on correct terminology.

  2. I wonder what the timing of the NW African IBD is? In other words, how much is Moorish, and how much dates to prehistory?

    1. IMO almost nothing is "Moorish" as in Islamic North African or even ancient Mauri of the Phoenician-Roman period: the North African element's distribution in Iberian is inconsistent with that kind of "casual geographical" flow because it does not follow any S-N cline but a W-E one. It's consistent with people settling not just Portugal and West Andalusia (but not East Andalusia!) but also Galicia, Leon, Asturias, etc. Even La Braña 1 appears to have something of that, so it's ancient, almost certainly pre-Neolithic.

      Anyhow affinity identification cannot alone discern the direction of flow and in this case there is also an even more important flow from Iberia to North Africa quite apparently. So careful, please.


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... ON (your comment may take some time, maybe days or weeks to appear).