The mystery of Lactase Persistence (LP) in Europeans

[Tabaccus Maximus]

I think the main question that paper attempts to answer is whether:

1) LP is native to Europe and was postively selected to present levels

OR

2) Did LP originate somewhere else, enter Europe at high levels, thus explaining its current high levels

This would be a good poll question

 

[Aberdeen]

I doubt if lactase persistence was native to any region prior to people in that region owning cattle and drinking milk on a regular basis. And I suspect that once a population began to consume milk on a regular basis, lactase persistence increased over time. I just question the idea of linking lactase persistence to any particular haplotype such as R1b. I doubt that Basques have a higher level of lactase persistence that Poles, for example. If they do, I would suspect that lactase persistence is dependent on genetics as much as it is milk consumption, in which case maybe you could link it to R1b in the past and perhaps even now in the case of populations that have remained more separate than most in recent centuries, such as Basques. But I suspect it's solely about what groups have been consuming large amounts milk in the past and continue to do so, in which case I would expect a more north/south bias than a west/east bias. From what I've seen, Slavs are just as avid milk drinkers as Germanic people and much more so than Iberians.

 

[ElHorsto]

Here is a fresh one:

http://all-that-is-interesting.com/tag/maps/

This map coincidentally shows a hot spot in Pakistan-Gedrosia. But the spot in Saudi-Arabia is surpising. Afterall different maps support the apparent disagreement and conflict regarding precise LP distributions.

 

[Greying Wanderer]

This map coincidentally shows a hot spot in Pakistan-Gedrosia. But the spot in Saudi-Arabia is surpising. Afterall different maps support the apparent disagreement and conflict regarding precise LP distributions.

Arabia is camel milk - same reason as for Europeans I guess, it was a critical part of the diet at some point in their past.

 

[Greying Wanderer]

So I guess that if lactase persistence correlates with R1b, and if we can estimate the countries with the highest lactase persistence based on per capital milk consumption, R1b must reach its greatest levels in countries like Sweden and Greece. Nope, not even close.

It depends if they include milk products like yoghurt - which don't require LP - and drinking milk directly.

 

[Goga]

Milk is not really popular in the region from the western parts of Turkey to northeastern parts of Iran, because folks there consume yoghurt and other 'dairy products' much more than in other places.

Yoghurt is much more popular in this area than pure freshly milk.

Personally I don’t like 'milk' or other 'dairy products' like cheese, Polish cheeses, sour cream, yoghurt, butter, milk etc. at all. Also I think that my organism can't handle milk, because after consuming 'fresh' (chocolate) milk, not a long time after that I've to go to the bathroom. It's strange because eating porridge or even consuming milkshake seems to be no problem.

Also, my brother drinks milk all the time, without any problem. But this is maybe because he always drank milk and I not. This is maybe why his body is accustomed to fresh milk.

 

[Greying Wanderer]

I doubt if lactase persistence was native to any region prior to people in that region owning cattle and drinking milk on a regular basis. And I suspect that once a population began to consume milk on a regular basis, lactase persistence increased over time. I just question the idea of linking lactase persistence to any particular haplotype such as R1b. I doubt that Basques have a higher level of lactase persistence that Poles, for example. If they do, I would suspect that lactase persistence is dependent on genetics as much as it is milk consumption, in which case maybe you could link it to R1b in the past and perhaps even now in the case of populations that have remained more separate than most in recent centuries, such as Basques. But I suspect it's solely about what groups have been consuming large amounts milk in the past and continue to do so, in which case I would expect a more north/south bias than a west/east bias. From what I've seen, Slavs are just as avid milk drinkers as Germanic people and much more so than Iberians.

"I doubt if lactase persistence was native to any region prior to people in that region owning cattle and drinking milk on a regular basis."

Agree - or rather disagree, I think it is a random mutation which can appear anywhere but which only spreads to large numbers if it is critical to survival in a particular region at a particular time.

.

"I just question the idea of linking lactase persistence to any particular haplotype such as R1b."

I think it is a correlation rather than causation i.e. LP was selected to very high levels in specific *regions* where milk drinking was critical to survival and there is a separate correlation between R1b and those regions i.e. R1b ended up in those regions where milk drinking was helpful to survival at some point in the past.

There is a LP correlation with northern I dna as well - which correlates with Funnelbeaker btw

http://www.stclairresearch.com/images/350px-Haplogroup_I.png

http://img534.imageshack.us/img534/6959/lactose.png

but for the same reason imo. It is the *region* that matters.

My guess is that northern zone wasn't as suitable for crops at that time so the people there relied on milk more - or because they got fewer calories from crops those people who could drink milk had more surviving kids.

(This doesn't mean the LP gene itself couldn't have come from the steppe (or anywhere else) originally just that when it arrived in this region it was selected for more strongly.)

 

[Greying Wanderer]

Milk is not really popular in the region from the western parts of Turkey to northeastern parts of Iran, because folks there consume yoghurt and other 'dairy products' much more than in other places.

Yoghurt is much more popular in this area than pure freshly milk.

Personally I don’t like 'milk' or other 'dairy products' like cheese, Polish cheeses, sour cream, yoghurt, butter, milk etc. at all. Also I think that my organism can't handle milk, because after consuming 'fresh' (chocolate) milk, not a long time after that I've to go to the bathroom. It's strange because eating porridge or even consuming milkshake seems to be no problem.

Also, my brother drinks milk all the time, without any problem. But this is maybe because he always drank milk and I not. This is maybe why his body is accustomed to fresh milk.

"It's strange because eating porridge or even consuming milkshake seems to be no problem."

Yes it's things like that which could explain how it spread. If non LP people can drink it okay in certain forms - like porridge - then that is how it could become a staple part of the diet. Then LP people who liked milk on its own could drink it and get more calories. This wouldn't have much effect in most places but in places where those extra calories made a big difference LP might spread.

 

[Maciamo]

I have added a section about lactase persistence and R1b cattle pastoralists on the R1b page. This way you have my opinion on the matter.

 

[LeBrok]

"I doubt if lactase persistence was native to any region prior to people in that region owning cattle and drinking milk on a regular basis."

Agree - or rather disagree, I think it is a random mutation which can appear anywhere but which only spreads to large numbers if it is critical to survival in a particular region at a particular time.

That's why the LP could only take hold and survive in already milk drinking cultures (even if it was only for kids), otherwise it wasn't needed nor beneficial.
It is like looking for white skin natives in Central Africa. So what if white skin mutation happened there, it never took hold because it wasn't beneficial in existing environment.

 

[LeBrok]

"It's strange because eating porridge or even consuming milkshake seems to be no problem."

Yes it's things like that which could explain how it spread. If non LP people can drink it okay in certain forms - like porridge - then that is how it could become a staple part of the diet. Then LP people who liked milk on its own could drink it and get more calories. This wouldn't have much effect in most places but in places where those extra calories made a big difference LP might spread.

Goga's case could be just bacterial flora of digestive system issue and not much to do with LP, which he could be a positive for. Bacterial flora consists of hundreds of different types of bacteria mostly symbiotic with humans. They take a big part in helping us digest all kinds of foods, or helping us digest more nutrients from certain food. According to our diet we will have different kinds of bacteria present, and we will miss not needed ones. For example people having low fat diet won't have bacteria to help them with fat digestion. Eating fatty food will give people indigestion and diarrhea. Eating a big piece of meat will cause similar problems for vegans. Likewise, drinking milk or cream in bigger portions will give diarrhea to a person who doesn't do it on regular bases. Change of any diet should be a slow and gradual process to let friendly bacteria build up in one's guts.

 

[martiko]

Goga's case could be just bacterial flora of digestive system issue and not much to do with LP, which he could be a positive for. Bacterial flora consists of hundreds of different types of bacteria mostly symbiotic with humans. They take a big part in helping us digest all kinds of foods, or helping us digest more nutrients from certain food. According to our diet we will have different kinds of bacteria present, and we will miss not needed ones. For example people having low fat diet won't have bacteria to help them with fat digestion. Eating fatty food will give people indigestion and diarrhea. Eating a big piece of meat will cause similar problems for vegans. Likewise, drinking milk or cream in bigger portions will give diarrhea to a person who doesn't do it on regular bases. Change of any diet should be a slow and gradual process to let friendly bacteria build up in one's guts.

very just leBrok !



Greying Wanderer , I know the Russia which I several times visited and I was the only one to put the milk in the morning in my coffee and to claim the cheese and the yoghurt, and it made laugh Russians.
In the Basque country it is often to see the old using chocolate with the milk or coffee as English drink tea to warm himself up in the afternoon.
When in the regions of consumption and production in France are Normandy, Brittany, Gascony and Basque country; and chance is it if it corresponds to the biggest concentration of R1b?

 

[Goga]

No, as you know I bought a DNA test on 23andme. According to their results I'm 'Lactose Intolerant' because my genotype is 'GG' at my marker: rs4988235 in MCM6 gene. I wonder from whom I've got this genotype, from my mother or father? Because as far as I know they both drink milk without any problem.
Also, according to them: "a person may have the GG genotype at the SNP reported here, but still be lactose tolerant."

 

[LeBrok]

No, as you know I bought a DNA test on 23andme. According to their results I'm 'Lactose Intolerant' because my genotype = 'GG' of MCM6 gene at my marker: rs4988235. I wonder from whom I've got this genotype, from my mother or father? Because as far as I know they both drink milk without any problem.
Also, according to them: "a person may have the GG genotype at the SNP reported here, but still be lactose tolerant."

What about st182549? Maciamo mentioned two genes responsible for LP in his writeup.

 

[Goga]

What about st182549? Maciamo mentioned two genes responsible for LP in his writeup.

23andme site doesn't mention rs182549. But I looked at my RAW DNA data and it seems that my rs182549 = CC. I don't know what that means... So my rs4988235 = GG and rs182549 = CC

 

[Goga]

Btw, I do agree with Maciamo. Environment and frequency of milk consumption can (de)activate genes at rs4988235 and rs182549 markers and that in Europe it has something to do with paternal haplogroup R1b!

 

[Greying Wanderer]

That's why the LP could only take hold and survive in already milk drinking cultures (even if it was only for kids), otherwise it wasn't needed nor beneficial.
It is like looking for white skin natives in Central Africa. So what if white skin mutation happened there, it never took hold because it wasn't beneficial in existing environment.

Yes exactly.

 

[Greying Wanderer]

very just leBrok !



Greying Wanderer , I know the Russia which I several times visited and I was the only one to put the milk in the morning in my coffee and to claim the cheese and the yoghurt, and it made laugh Russians.
In the Basque country it is often to see the old using chocolate with the milk or coffee as English drink tea to warm himself up in the afternoon.
When in the regions of consumption and production in France are Normandy, Brittany, Gascony and Basque country; and chance is it if it corresponds to the biggest concentration of R1b?

Yes but in Sweden it corresponds to R1a, R1b and I *or* looking at it another way it corresponds to Sweden regardless of haplogroup.. I'm not saying it didn't *arise* among R1b on the steppe. It might well have. I'm just saying it spread the most in certain *regions* and that's the interesting bit to me. What was it about those regions (Atlantic Coast and Northwest Europe) that made milk so critical at some point in the past? I think it was because crops didn't grow well in those regions but cattle did. If that's the case and those regions were where milk drinking was *most* critical then those regions might also be the places where cattle-breeding was most critical also.

 

[LeBrok]

Yes but in Sweden it corresponds to R1a, R1b and I *or* looking at it another way it corresponds to Sweden regardless of haplogroup.. I'm not saying it didn't *arise* among R1b on the steppe. It might well have. I'm just saying it spread the most in certain *regions* and that's the interesting bit to me. What was it about those regions (Atlantic Coast and Northwest Europe) that made milk so critical at some point in the past? I think it was because crops didn't grow well in those regions but cattle did. If that's the case and those regions were where milk drinking was *most* critical then those regions might also be the places where cattle-breeding was most critical also.

I think it is sort of "miracle" that in long winter times up North, when nothing much grows to eat, people can feed dry grass to cows and receive steady supply of dairy products, plus meat.

 

[MOESAN]

I think the main question that paper attempts to answer is whether:

1) LP is native to Europe and was postively selected to present levels

OR

2) Did LP originate somewhere else, enter Europe at high levels, thus explaining its current high levels

This would be a good poll question

Good clearing -
Very interesting opinions! And sensible -
LP tolerance gene mutation could be old enough and took off concerning %s when milk entered in the diet of populations, presenting an advantage (Aberdeen) so for the most among herders populations, nothing new here – whatever the HG group where this mutation arose, by contacts between populations, a selective gene can grow very quickly even in a population where the gene is newly arrived -
at the contrary, if the mutated gene does not offer any risk for health EVEN when it is no more of any use (change in the diet decreasing the weight of milk), the LP tolerance gene can perdure a very long time without any big change in %s in the population -
surely Bronze I-Eans played a big role in the spreading of the mutation, but surely enough too neolithical breeders populations had this gene too – but if they began making cheese early enough, this can have reduced the need of the LP gene presence? Explaining the difference between North and South for a big part?
&: the today statistics about milk consomption in the world do not precisely show us the consomption by age: a global high quantity of milk drunk in a country could be based for a big part upon the 1 to 10 years old people?