A couple of interesting quotes from this story:
That next step happened slowly, and it seems to have required the spread of lactase persistence. The LP allele did not become common in the population until some time after it first emerged: Burger has looked for the mutation in samples of ancient human DNA and has found it only as far back as 6,500 years ago in northern Germany.
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Some of the LeCHE participants are now probing further back in time, as part of a project named BEAN (Bridging the European and Anatolian Neolithic), which is looking at how the first farmers and herders made their way into Europe. Burger, Thomas and their BEAN collaborators will be in Turkey this summer, tracing the origins of the Neolithic using computer models and ancient-DNA analysis in the hope of better understanding who the early farmers were, and when they arrived in Europe.
15 comments:
Interesting , but Looking at their own map - Greece and Southern Italy look above the 40% level - as they're more tolerant than Northern Italy, most of Turkey and most of Spain/Iberia and equal to to a good chunk of Germany and Scandinavia and what not. So their "less than 40% for Greece" comment is hard to make sense outve as they certainly look in the above 55-60% range following their tile shades with the darkest blue representing the 90-100% .
That said, their map though seems more accurate than some of the others I seen online as Southern Italians lactose intolerance is WAY over estimated for whatever reason.
"In a study of 323 Sicilian adults, Carroccio et al. (1998) found only 4% were both lactose intolerant and lactose maldigesters, while 32.2% were lactose maldigesters but did not test as lactose intolerant."
Because sicily isn't all of southern italy, every region of italy is fairly distinct. It's also got tons of dna from all over the place.
And didn't Sicily get a significant amount of DNA from the Normans? If they did then this might explain the relatively low level of lactose intolerance in Sicily.
It takes longer for bacteria to break down lactase at colder temperatures. yoghurt setting times in temperate regions are significantly slower as compared to subtropical and tropical regions.
So persistance may have occured first in europe. What aboutpersistance in Africa isnt it of independent origin?
Half-way off topic, but this caught my attention.
It seems that Basque people have the highest frequency of the Rhesus negative Blood type among all Europeans, which is more or less absent in the rest of the world. Interesting how something like this can develop in regard to a higher chance of damaging “the second born” fetus or newborn.
Rh blood group system
http://en.wikipedia.org/wiki/Rhesus_Factor
"What about persistance in Africa isnt it of independent origin?"
Partially. Some LP genes in Africa are different from those in Europe, so a test of European LP genes underestimates LP gene frequency in Africa.
I recall a study on aDNA from medieval period people that claimed, the high levels of lactose tolerance in northern Europe to be "quiet recent".
I somehow recall numbers like
Lactose tolerance genes Germany (based on aDNA check):
1000AD = 30%
1500AD = 50%
2012AD = 70-80%
Fanty, "Germany"?
What does that even mean? Does it refer to the formerly Celtic areas in the south, where cattle were the basis of the economy and culture? Does it mean the modern boundaries of the BRD? (i.e minus Silesia, the Sudentenland, the Siebengebirge and all those other areas formeerly inhabited by people who called themselves German, whatever their actual genetic backgrounds?
And those earlier percentages - are they based on anything other than whatever remains people have happened across still in some kind of shape to test? And the same questions apply to them as above.
@Jim:
The earlier percentages base on aDNA tests of people in medieval German graves. 30% of the tested indiviuals from the 10th century had the alleles. 50% of the tested 16th century people.
The whole study was all about how quickly DNA does change in a population over time. So I think they tested about the same areas, otherwise those numbers would be crap.
What "Germany" means? Well, I guess it means core Germany (what is now Germany), no assimilated slavic terretories etc.
Technicall of course, "Germany" is a language area. "Rihhi der tiutschen Zungen" = Realm of the German speakers in 10th century German.
Like the Kings official German name is "Kuning der tiutschen Zungen" = King of the German speakers.
The Austrian singer Walter von der Vogelweide (late 12th and early 13th century) adresses the population in the period when the throne was empty like this (in a song about the Reich):
"Woe to you German speakers! Whathappend to your glorious Reich? Why is it so desolate? Even the bees have their king, but you do not? The round crowns (oposed to the octagonal imperial crown) rise! Phillip put on the (imperial)crown and drive them back to their rightfull places!"
Whatever....
As I said, it was about how quickly single genetical traits change (spread) in a population. 30% to 80% in 1000 years.
The claim was, that the consumation of milk increased in that period and that may have somehow boosted the spread of the ability to digest it at all.
It seems some corrections are due on the Vitamin D issue, and on Spain.
I am reading an article on realist Convivencia and "genealogical mentalities" by David Nirenberg. There he states what we all know: proud clean linage there meant no Muslim and no Jew ancestry, but Visigothic (northerner) ancestry.
There is a clear example of replacement in the Reconquista, how the northerners, those descending from Visigoths,Suevi, Alans, Vandals, yes the Basque, slowly recovered the territory from the Moores. The Atalantic's Spaniards are closer to other atlantic people, and quite unlike Mediterranean people.
Fanty, thanks. That seems reasonable - "Germany" is nebulous but not to the point of uselesness.
The problem is that it leaves you with the task of showing a genetic disparity between those ancestrally Germanic-speaking and Slavic-speaking populations. There is enough linguistic evidence to indicate a period of close contact that it would require a fair bit of prvong to claim there was no intermarriage.
That rapid a spread is reasonable too; it's just that it's based on what yoyu have to admit is a very small and maybe not so reliable sample.
But that rapaid a spread raises another question: why would it take so long to spread after it arose, during a period when the same selective pressure applied throughout the period?
I don't think you can talk about fast spread when you look at a very heterogenous population like all the german states. Especially since a lot of the DNA is obviously from elsewhere and the sampling is in large trade cities.
DNA does spread fast within a population, very fast. But they were really picking this up out of the celts so if anything their study showed how slowly (but completely) they integrated in germanic areas.
If they were really one population it would have spread much faster.
But that's also why you have to be wary genetic samples. Farmers in fertile valleys, fishermen along the coast, traders, and plainsmen are likely to be quite distinct in their DNA.
Their map of european lactose tolerance looks more like an expansion from the Atlantic coast generally and in particular somewhere around Frisia / Holstein - perhaps two, an Atlantic expansion first and a later Holstein one.
http://www.nature.com/news/500020a-i2-0-jpg-7.11661?article=1.13471
Funnelbeakers maybe or their GA successors?
The ending of the climatic optimum around 5000 BP may have provided the incentive to modify the existing farming package.
http://en.wikipedia.org/wiki/Holocene_climatic_optimum
Coincidentally cattle from that same region are today the world's highest-production dairy animals.
http://en.wikipedia.org/wiki/Holstein_Friesian_cattle
"The Dutch breeders bred and oversaw the development of the breed with the goal of obtaining animals that could best use grass, the area's most abundant resource."
nb If you look at the West African, Indian and Arabian LP distributions on the map what do you see?
You see a high LP core region declining with distance from the core.
@
"an Atlantic expansion first and a later Holstein one."
A possible mechanism for a two stage process would be...
If oxen in the original neolithic package were primarily draft animals.
and
If cattle produce much more meat and milk in regions of consistent high rainfall (because it makes the grass particularly lush).
then
as the Atlantic coast has consistent high rainfall,
http://imageshack.us/f/527/eurprcyfz7.jpg/
the Atlantic coast (along with the Dinaric alps) provides a good candidate for a region where the neolithic package was modified to increase the input from cattle.
Purely for illustration of the idea say:
Original package: 60% crops, 30% sheep and 10% oxen
Modified package: 30% crops, 30% sheep, 30% cattle, 10% oxen.
This should be disprovable imo as if it happened and it was a coastal phenomenon (because of the rainfall patterns) then you should see a transition in the archealogy from mainly coastal settlements to more inland settlements combined with a large increase in the number of cattle bones.
Also if it was related to rainfall patterns the cost/benefit might mean the modified package was initially restricted to the Atlantic Coast (including Britain and Ireland).
That would be the first stage.
@
The end of the climactic optimum might have provided the impetus for part or all of this process.
@
Apart from a simple shift in the proportions of cattle in the farming package there are two other ways cattle rasing might create a step-change in population numbers.
1) Lactose tolerance - more calories from the same output.
2) More output i.e. breeding for milk and meat production
(If oxen were initially primarily draft animals then size and strength would be prized alongside meat and milk production. Once meat and milk producing breeds were separated out from draft breeds you might expect to see a dramatic increase in yield.)
So a secondary expansion from the Funnelbeaker region could have been the result of either of those two things.
Looking at the LP distribution map in the article
http://www.nature.com/news/500020a-i2-0-jpg-7.11661?article=1.13471
might suggest the first option however i think it's equally possible that it was the creation of a cattle-raising zone through farming methods which created the conditions for LP to spread within that zone.
Sorry to be late, a very mexican trait.
Special attention should be paid to the Damned peoples of Spain, not unusually related to cattle rising, sheparding, and a non-stationary life. Bottle necks created by exclusion: Los agotes, Los maragatos, Los vaqueiros de alzada, Los quinquis and
Los pasiegos.
The Pasiegos are specially interesting, they make great cheese and not unsually are E1b1b1b (M81) and mtDNA U6 and V; ancient Semitic and African pastoralists.
Would that mean two ways of milk tolerant people arriving in Iberia, not just the Atlantic-European.
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