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epoch
21-12-13, 15:42
Hi forum,

Recently genetic information from two mesolithic hunter-gatherer burials from La Brana in northern Spain has been published. I have read a number of articles about it and I am confused by the results. The main reason for my confusion lies in the fact that the la Brana skeleton seem related to northern Europe rather than the current day local Iberian population. The two carried mtDNA U5b2c1 which is not very abundant in current day Iberia - neither is any U5 - and the full sequence show relation to northern European population rather than local. The results are presented as evidence for a large population overhaul during the Neolithic transition in Iberia.

http://dienekes.blogspot.nl/2012/06/mesolithic-iberians-la-brana-arintero.html
http://eurogenes.blogspot.com.au/2013/12/brana-1-had-blue-eyes.html

Mesolithic and upper paleolithic mtDNA recovered until recently is mostly U4 and U5, and we do have quite a number of finds.

http://www.eupedia.com/europe/ancient_european_dna.shtml
http://www.ancestraljourneys.org/ancientdna.shtml


The autosomal genetic relation with northern Europe is all good and well were it that northern European population, which the la Brana autosomal DNA is clearly related to, would have carried lots U5. That is true for Finland, the Saami and the Baltic region - although in the latter U, U4 + U5 does not exceed the 21% - but it isn't true for most of the northwestern European culture, including Sweden, Denmark and Norway. There have been Farmers from the neolithic have been sequenced as well as hunter-gatherers from the Pitted Ware culture, found on Gotland. Mitochondrial DNA showed greet difference between the mainland Swedes and the hunter-gatherers, presented as evidence for.. you guessed it: a population overhaul in Sweden after the arrival of the neolithic.

http://ac.els-cdn.com/S0960982209016947/1-s2.0-S0960982209016947-main.pdf?_tid=4cbb9e4e-6a43-11e3-964c-00000aacb35f&acdnat=1387632483_de9e8b5f85e80f8936c82a48bacac689

However, autosomal DNA between the northerners with and those without a strong U5 presence hardly differs. Also, phenotypes are remarkably similar. And the autosomal admixture is mostly north European in both Finnish and Swedish samples. Even both the la Brana and the Gotland Pitted Ware samples show autosomical relation to Swedish and Saami rather than Saami.

http://1.bp.blogspot.com/-F9XoyN2wE-w/ToZBZZT7jdI/AAAAAAAAAmI/qwmGu64Xvwk/s1600/admixture.png
http://fennoscandia.blogspot.nl/2013/09/la-brana-2-and-modern-european-variation.html
http://fennoscandia.blogspot.nl/2013/11/ajv52-and-european-variation-ii.html?showComment=1383942706763

This is very strange. Autosomal evidence points to relation between mesolithic hunter-gatherers and current day northwest Europeans, whereas mtDNA points to a population overhaul. We pretty much know mesolithic and paleolithic hunter-gatherers had mostly mtDNA U (U, U4, U5) which is not very common nowadays.

How can this both be true? How can the northwest European population - a population which wikipedia describes as almost genetically indistinguishable - bear such genetic resemblance to hunter-gatherers if they aren't related to them, as the great difference in mtDNA suggests?

More links:

http://forwhattheywereweare.blogspot.nl/2010/11/ancient-mtdna-advance-maps.html
http://eurogenes.blogspot.nl/2013/02/post-mesolithic-population.html

Wilhelm
21-12-13, 17:11
The two carried mtDNA U5b2c1 which is not very abundant in current day Iberia - neither is any U5 -
Where do you get that ? Because as far as I know, northern Iberia has one of the highest peaks of U5 in Europe (the Cantabria-Basque area), reaching near 20%

Idun
21-12-13, 17:54
Where do you get that ? Because as far as I know, northern Iberia has one of the highest peaks of U5 in Europe (the Cantabria-Basque area), reaching near 20%1


The area is a strategic route that was also used and fought and over during the migration period.
Im not claiming it a fact but a possibility for the origin.

epoch
21-12-13, 20:09
Where do you get that ? Because as far as I know, northern Iberia has one of the highest peaks of U5 in Europe (the Cantabria-Basque area), reaching near 20%

I got this from this

http://www.eupedia.com/europe/european_mtdna_haplogroups_frequency.shtml

However, I now see the map Maciamo made and indeed it shows up to 20% in some northern regions.

http://www.eupedia.com/forum/threads/29157-New-map-of-mtDNA-haplogroup-U5

The again, it hardly changes my point that current day U, U5 and U4 is only a minority of the mtDNA lineages in most of the rest of Spain and most of Northern Europe. Still, autosomically the la Brana samples show to be related to the northern Europeans. How can that be? Dienekes had an article on how the neolithic societies absorbed the mesolithic hunters, and claims that only a minority of current day maternal lines stem from mesolithic hunters. If that would be so, how come the Swedes, which hardly have any U5, show such strong affinity with mesolithic hunters?

http://dienekes.blogspot.nl/2012/03/neolithic-expansions-how-european.html

Mind you, it is very interesting what you said, since the genetic outlier in Iberia is the west Pyrenees, where the Basque live. A population that also shows more northern and north western affinity. Or am I missing something or misreading something?

Sile
21-12-13, 20:47
I got this from this

http://www.eupedia.com/europe/european_mtdna_haplogroups_frequency.shtml

However, I now see the map Maciamo made and indeed it shows up to 20% in some northern regions.

http://www.eupedia.com/forum/threads/29157-New-map-of-mtDNA-haplogroup-U5

However, it hardly changes my point that current day U, U5 and U4 is only a minority of the mtDNA lineages in most of the rest of Spain and most of Northern Europe. However, autosomically the la Brana samples a related to the northern Europeans. How can that be? Dienekes had an article on how the neolithic societies absorbed the mesolithic hunters, and claims that only a minority of current day maternal lines stem from mesolithic hunters. If that would be so, how come the Swedes, which hardly have any U5, show such strong affinity with mesolithic hunters?

http://dienekes.blogspot.nl/2012/03/neolithic-expansions-how-european.html

Mind you, it is very interesting what you said, since the genetic outlier in Iberia is the west Pyrenees, where the Basque live. A population that also shows more northern and north western affinity. Or am I missing something or misreading something?

The recent alpine paper for south Tyrol, trentino and northern veneto has over 200 Mtdna tested, with U5 being second in percentage after K1. Since this area is otzi area, we can guess the iberic burials might have the same markers

epoch
21-12-13, 21:00
The recent alpine paper for south Tyrol, trentino and northern veneto has over 200 Mtdna tested, with U5 being second in percentage after K1. Since this area is otzi area, we can guess the iberic burials might have the same markers

But Otzi was far less related to north Europe. Even the farmers at Gokhem showed more relation to local hunter-gatherers.

Sile
21-12-13, 21:16
But Otzi was far less related to north Europe. Even the farmers at Gokhem showed more relation to local hunter-gatherers.

Wasn't the Gokhem in scandinavia burial a female?

epoch
21-12-13, 21:28
Wasn't the Gokhem in scandinavia burial a female?

I don't know. Would it make a difference?

epoch
21-12-13, 21:42
Apparently there is an initiative to test hundreds of remains from south Sweden for mtDNA, Y-DNA and autosomal DNA. I guess I just have to wait then.

http://polishgenes.blogspot.nl/2013/04/hundreds-of-prehistoric-scandinavian.html

MOESAN
22-12-13, 00:41
I red somwhere mt DNA was under influence of natural selection...? what is not amazing considering it this "guest" DNA has a metabolic function in cells

epoch
22-12-13, 11:38
I red somwhere mt DNA was under influence of natural selection...? what is not amazing considering it this "guest" DNA has a metabolic function in cells

There are finds of Pitted Ware burials, that lived alongside farmers. They show the same amount of U as mesolithic hunter-gatherers.

epoch
24-12-13, 11:21
http://eurogenes.blogspot.com/2013/12/ancient-human-genomes-suggest-three.html?showComment=1387851513157#c161663205072 1459316

There you have it. North Western admixture is a mesolithic inheritence. Or signal. Or whatever you want to call it. This finding may also vindicate the Germanic Substrate theory and explain the continuity seen in Ertebolla and Funnel Beaker Culture.

james stock
24-12-13, 16:28
http://eurogenes.blogspot.com/2013/12/ancient-human-genomes-suggest-three.html?showComment=138785151361663205072145931 6 (http://eurogenes.blogspot.com/2013/12/ancient-human-genomes-suggest-three.html?showComment=1387851513157#c161663205072 1459316)

There you have it. North Western admixture is a mesolithic inheritence. Or signal. Or whatever you want to call it. This finding may also vindicate the Germanic Substrate theory and explain the continuity seen in Ertebolla and Funnel Beaker Culture.

From Eurogenes...


Loschbour - Y-DNA I2a1bMotala 2 - Y-DNA I
Motala 3 -Y-DNA I2
Motala12 - I2a1b

Looks like the samples are I2a1b, putting a dent in the idiotic "i2a1b-din is only 2000 years old" nonsense that Albanians and Ken N. parroted for years.

sparkey
24-12-13, 18:30
From Eurogenes...


Loschbour - Y-DNA I2a1bMotala 2 - Y-DNA I
Motala 3 -Y-DNA I2
Motala12 - I2a1b

Looks like the samples are I2a1b, putting a dent in the idiotic "i2a1b-din is only 2000 years old" nonsense that Albanians and Ken N. parroted for years.

You don't know what you're talking about. Neither sample was I2a-Din. Loschbour was confirmed I2a1b* L621- L161-. The L621- means not I2a-Din, because I2a-Din is L621+. Nordtvedt places I2a1b as a whole at about 16k years old, so no contradiction. Similarly, Motala12 was I2a1b L621-, and hence not I2a-Din. It could have been I2a-Isles L161+ in theory, but could also have been I2a1b* like Loschbour. Again, no contradiction.

james stock
24-12-13, 22:27
You don't know what you're talking few put. Neither sample was I2a-Din. Loschbour was confirmed I2a1b* L621- L161-. The L621- means not I2a-Din, because I2a-Din is L621+. Nordtvedt places I2a1b as a whole at about 16k years old, so no contradiction. Similarly, Motala12 was I2a1b L621-, and hence not I2a-Din. It could have been I2a-Isles L161+ in theory, but could also have been I2a1b* like Loschbour. Again, no contradiction.

Yes, I2a1b l178 was found amonst the samples. I2a1b l178/m423 is dated at 8k years +/- 4k years. We now have samples at 8k years that confirms l178 is present so the lower range of l178 of 4-8k years is now thrown out. The same can probably be said about i2a1b din.

Similarily , it's only a matter of time until the models are irrelevant because we have accumulated enough data through fossils to actually date each haplogroup.

sparkey
24-12-13, 23:35
Yes, I2a1b l178 was found amonst the samples. I2a1b l178/m423 is dated at 8k years +/- 4k years. We now have samples at 8k years that confirms l178 is present so the lower range of l178 of 4-8k years is now thrown out. The same can probably be said about i2a1b din.

Who dates M423/L178 at 8k years? Nordtvedt dates the TMRCA of all known branches at ~12k and its overall clade age (which is the important one for testing in this case) at ~16k, as I said. See here (http://knordtvedt.home.bresnan.net/Tree%20and%20Map%20for%20Hg%20I.pdf).


Similarily , it's only a matter of time until the models are irrelevant because we have accumulated enough data through fossils to actually date each haplogroup.

It will even be possible to validate existing dating models once we have enough ancient DNA. As is, any validation gives too large error bars.

james stock
25-12-13, 01:02
Who dates M423/L178 at 8k years? Nordtvedt dates the TMRCA of all known branches at ~12k and its overall clade age (which is the important one for testing in this case) at ~16k, as I said. See here (http://knordtvedt.home.bresnan.net/Tree%20and%20Map%20for%20Hg%20I.pdf).



It will even be possible to validate existing dating models once we have enough ancient DNA. As is, any validation gives too large error bars.

It doesn't seem that you understand how models work. If we create a model that is completely predictive of all known data, it will not give us certainty that that same model will be predictive of unknown data. Even if the model predicts unknown data, it is not proof that the model will predict further unknown data. If a model predicts all unknown data that became known, it is not proof that the model will predict future data. It is therefore impossible to validate a model.

sparkey
25-12-13, 01:32
It doesn't seem that you understand how models work. If we create a model that is completely predictive of all known data, it will not give us certainty that that same model will be predictive of unknown data. Even if the model predicts unknown data, it is not proof that the model will predict further unknown data. If a model predicts all unknown data that became known, it is not proof that the model will predict future data. It is therefore impossible to validate a model.

You're reaching an absurdity because your definition of "validation" is too strict. We wouldn't be looking for proof that a model will predict all unknown data, we would be looking for proof that our model has correctly predicted known data, which would give evidence toward whether or not such a model would predict unknown data. You're basically arguing that you can't train a predictive algorithm, which is almost always false.

james stock
25-12-13, 01:43
Who dates M423/L178 at 8k years? Nordtvedt dates the TMRCA of all known branches at ~12k and its overall clade age (which is the important one for testing in this case) at ~16k, as I said. See here (http://knordtvedt.home.bresnan.net/Tree%20and%20Map%20for%20Hg%20I.pdf).



It will even be possible to validate existing dating models once we have enough ancient DNA. As is, any validation gives too large error bars.


You're reaching an absurdity because your definition of "validation" is too strict. We wouldn't be looking for proof that a model will predict all unknown data, we would be looking for proof that our model has correctly predicted known data, which would give evidence toward whether or not such a model would predict unknown data. You're basically arguing that you can't train a predictive algorithm, which is almost always false.
No, what I was saying was that models will always be prone to error and that they cannot be validated. There may be periods that have rapid mutation, aka Ghould's punctuated equilibrium, and mutaion rates in the future will most certainly be in the hands of genetic engineers.

Certain random events are impossible to model.

sparkey
25-12-13, 01:55
No, what I was saying was that models will always be prone to error and that they cannot be validated. There may be periods that have rapid mutation, aka Ghould's punctuated equilibrium, and mutaion rates in the future will most certainly be in the hands of genetic engineers.

Certain random events are impossible to model.

The idea that Y-line mutation rates aren't too random to model is an assumption that we'd be validating, though. That's the point. If the model consistently predicts the age of ancient samples across time and place, then tada, we've validated. If it gets some groups wrong and others right, or systematically gets all groups wrong but in different ways, then that assumption is incorrect, and we'll need to adjust or train our model somehow to be able to cope with the apparent randomness. If it still doesn't work for other groups coming in, then we can assume that it is too random to model. But not before then.

LeBrok
25-12-13, 02:02
No, what I was saying was that models will always be prone to error and that they cannot be validated. There may be periods that have rapid mutation, aka Ghould's punctuated equilibrium, and mutaion rates in the future will most certainly be in the hands of genetic engineers.

Certain random events are impossible to model.
The model works in realm of statistical probabilities. It means that it will predict most of mutations timing right. It doesn't mean that it will predict all of them correctly. It is not a perfect tool but it is the best we have, and it will be in use till someone invents more precise one, yet always based on probabilities.

james stock
25-12-13, 04:14
The idea that Y-line mutation rates aren't too random to model is an assumption that we'd be validating, though. That's the point. If the model consistently predicts the age of ancient samples across time and place, then tada, we've validated. If it gets some groups wrong and others right, or systematically gets all groups wrong but in different ways, then that assumption is incorrect, and we'll need to adjust or train our model somehow to be able to cope with the apparent randomness. If it still doesn't work for other groups coming in, then we can assume that it is too random to model. But not before then.

You cannot validate a model. I tried to explain that to you with logic, but you don't seem to understand. Models work until they don't, and when they stop working (think economic models) the results can be devastating.


The model works in realm of statistical probabilities. It means that it will predict most of mutations timing right. It doesn't mean that it will predict all of them correctly. It is not a perfect tool but it is the best we have, and it will be in use till someone invents more precise one, yet always based on probabilities.

The most precise method is to sequence and date skeletons.

LeBrok
25-12-13, 10:09
You cannot validate a model. I tried to explain that to you with logic, but you don't seem to understand. Models work until they don't, and when they stop working (think economic models) the results can be devastating.
What do you mean by stopped working? Do you mean recent economic hiccup?




The most precise method is to sequence and date skeletons.If we can find all the skeletons with new haplogroup mutations at the time they occur it would be the best thing for dating. Do you know what are the odds of finding them?

sparkey
25-12-13, 10:29
You cannot validate a model. I tried to explain that to you with logic, but you don't seem to understand. Models work until they don't, and when they stop working (think economic models) the results can be devastating.

I understand exactly what you're saying, you're just wrong. We're not talking about proving that models always work and always will work no matter how circumstances change. We're talking about normal model validation, where we compare predicted results to actual results, and chart the differences across different data sets.

MOESAN
26-12-13, 13:50
But Otzi was far less related to north Europe. Even the farmers at Gokhem showed more relation to local hunter-gatherers.

Otzi was from the beginning of the metals era; and surely it was a "mix" of pre-neolithic and neolithic people and perhaps other ones! - all the way the relation between autosomals (approximative poolings) and mt DNA or Y-DNA IN AN UNIQUE INDIVIDUAL is of a very low confidence - as time was passing an history running on the populations got more and more mixed, even if not with the same average speed and so the previous statistical links between these three kinds of genes got looser and looser -

MOESAN
26-12-13, 13:57
I don't know. Would it make a difference?

I'm trying to assimilate this new thread so I do just some remarks concerning my understanding of some points before doing more -
the female-male difference at some periods of possible new contacts between populations of different origins can have some importance: in history some rate of exchange of females between (new?) neighbouring populations seem checked - even after some generations of bipolar mixings some differences can remaind between two populations and the keeping on exchanges can yet send some differences between males and females "mean" autosomals...

MOESAN
26-12-13, 14:04
[QUOTE=epoch;422484]Hi forum,

Recently genetic information from two mesolithic hunter-gatherer burials from La Brana in northern Spain has been published. I have read a number of articles about it and I am confused by the results. The main reason for my confusion lies in the fact that the la Brana skeleton seem related to northern Europe rather than the current day local Iberian population. The two carried mtDNA U5b2c1 which is not very abundant in current day Iberia - neither is any U5 - and the full sequence show relation to northern European population rather than local. The results are presented as evidence for a large population overhaul during the Neolithic transition in Iberia.

http://dienekes.blogspot.nl/2012/06/mesolithic-iberians-la-brana-arintero.html
http://eurogenes.blogspot.com.au/2013/12/brana-1-had-blue-eyes.html

Mesolithic and upper paleolithic mtDNA recovered until recently is mostly U4 and U5, and we do have quite a number of finds.

http://www.eupedia.com/europe/ancient_european_dna.shtml
http://www.ancestraljourneys.org/ancientdna.shtml


The autosomal genetic relation with northern Europe is all good and well were it that northern European population, which the la Brana autosomal DNA is clearly related to, would have carried lots U5. That is true for Finland, the Saami and the Baltic region - although in the latter U, U4 + U5 does not exceed the 21% - but it isn't true for most of the northwestern European culture, including Sweden, Denmark and Norway. There have been Farmers from the neolithic have been sequenced as well as hunter-gatherers from the Pitted Ware culture, found on Gotland. Mitochondrial DNA showed greet difference between the mainland Swedes and the hunter-gatherers, presented as evidence for.. you guessed it: a population overhaul in Sweden after the arrival of the neolithic.

http://ac.els-cdn.com/S0960982209016947/1-s2.0-S0960982209016947-main.pdf?_tid=4cbb9e4e-6a43-11e3-964c-00000aacb35f&acdnat=1387632483_de9e8b5f85e80f8936c82a48bacac689

However, autosomal DNA between the northerners with and those without a strong U5 presence hardly differs. Also, phenotypes are remarkably similar. And the autosomal admixture is mostly north European in both Finnish and Swedish samples. Even both the la Brana and the Gotland Pitted Ware samples show autosomical relation to Swedish and Saami rather than Saami.

"northern Europe" autosomals pooling is very rough and I think N-W differ from N-E - and we have few and scarce samples <> what kind of Finns? (Finland population is less homogenous (I don't say "pure", but homogenous- on its territory than roughly the all Scandinavian even if in Norway - Saami have chances to be a severely drifted population

Idun
26-12-13, 14:07
I'm trying to assimilate this new thread so I do just some remarks concerning my understanding of some points before doing more -
the female-male difference at some periods of possible new contacts between populations of different origins can have some importance: in history some rate of exchange of females between (new?) neighbouring populations seem checked - even after some generations of bipolar mixings some differences can remaind between two populations and the keeping on exchanges can yet send some differences between males and females "mean" autosomals...

The exchange of females is found with Uralics, part of not marrying in the same clan and used also sealing an alliance and peace, I believe it dates back to the mammoth steppe.

U5 > East
H < West

Get the idea?

MOESAN
26-12-13, 14:12
There are finds of Pitted Ware burials, that lived alongside farmers. They show the same amount of U as mesolithic hunter-gatherers.

thanks; but: what sample size? where and when? i'm interested -
we have a lot of parameters to take in account - some neolithicized population of W and N Europe showed phenotypically they were accultured ancient mesolithic populations poorly penetrated by true first farmers genes: it complicates the problem of classification

Idun
26-12-13, 14:26
I will give you an interesting snippet, Finnish word for mother, Ă„iti, comes from Gothic Aithe.
Traditional Finnic word would be Emo.

adamo
26-12-13, 18:13
I hope Elmo isn't traditionally Finnish as well or that would be pretty catastrophic if combined with emo.

Angela
26-12-13, 19:24
Otzi was from the beginning of the metals era; and surely it was a "mix" of pre-neolithic and neolithic people and perhaps other ones! - all the way the relation between autosomals (approximative poolings) and mt DNA or Y-DNA IN AN UNIQUE INDIVIDUAL is of a very low confidence - as time was passing an history running on the populations got more and more mixed, even if not with the same average speed and so the previous statistical links between these three kinds of genes got looser and looser -

Your point about the relationship between autosomal DNA and uniparental markers in an un unique individual is often lost sight of, but it is extremely important in my view.

However, even when looking at populations, or breeding groups, I think it's becoming more and more clear that uniparental markers are volatile and we can see big changes without changes of a proportionate size in the autosomal composition, and I think differential mating patterns, especially in terms of yDNA, founder effect and subsequent drift, selection for different mtDNA and yDNA subclades in the face of a changed climatic or personal environment, and also, (which is not often explored) sheer random chance, can affect the frequency of these uniparental markers. To the last point, a study was done of Icelandic mtDNA covering 300 years. No new geneflow, and yet because of the differential pattern of "daughtering out", certain sub-clades became rare, and others dominant. If anyone is interested, I'll try to find the site, but I'm not making it up!:)

Idun
26-12-13, 20:17
Your point about the relationship between autosomal DNA and uniparental markers in an un unique individual is often lost sight of, but it is extremely important in my view.

However, even when looking at populations, or breeding groups, I think it's becoming more and more clear that uniparental markers are volatile and we can see big changes without changes of a proportionate size in the autosomal composition, and I think differential mating patterns, especially in terms of yDNA, founder effect and subsequent drift, selection for different mtDNA and yDNA subclades in the face of a changed climatic or personal environment, and also, (which is not often explored) sheer random chance, can affect the frequency of these uniparental markers. To the last point, a study was done of Icelandic mtDNA covering 300 years. No new geneflow, and yet because of the differential pattern of "daughtering out", certain sub-clades became rare, and others dominant. If anyone is interested, I'll try to find the site, but I'm not making it up!:)

Im interested, please try. =)

epoch
26-12-13, 20:48
The exchange of females is found with Uralics, part of not marrying in the same clan and used also sealing an alliance and peace, I believe it dates back to the mammoth steppe.

U5 > East
H < West

Get the idea?

I figured that too. Suppose France and the Benelux (the latter having a culture of which archeological evidence shows continuity from hunter-gathering to some form of farming, the Swifterband cuklture) were the home of a different mesolithic hunter-gatherer population, whose later lineages then provided H1 and H3 to Western Europa. The area was hardly tested. However, the first result from Luxembourg is, you guessed it, U5.

For H1 and H3 to be derived from hunter-gatherers we need a number of supporting results.

epoch
26-12-13, 20:52
However, even when looking at populations, or breeding groups, I think it's becoming more and more clear that uniparental markers are volatile and we can see big changes without changes of a proportionate size in the autosomal composition, and I think differential mating patterns, especially in terms of yDNA, founder effect and subsequent drift, selection for different mtDNA and yDNA subclades in the face of a changed climatic or personal environment, and also, (which is not often explored) sheer random chance, can affect the frequency of these uniparental markers. To the last point, a study was done of Icelandic mtDNA covering 300 years. No new geneflow, and yet because of the differential pattern of "daughtering out", certain sub-clades became rare, and others dominant. If anyone is interested, I'll try to find the site, but I'm not making it up!:)

I thinks this answers my initial question. However, U5 and U4 declined *everywhere* - apart from the fringes - in the area where the latest study shows large Western Hunter Gatherer admixture. It gets stranger and stranger.

http://eurogenes.blogspot.nl/2013/12/ancient-human-genomes-suggest-three.html

epoch
26-12-13, 20:53
thanks; but: what sample size? where and when? i'm interested -
we have a lot of parameters to take in account - some neolithicized population of W and N Europe showed phenotypically they were accultured ancient mesolithic populations poorly penetrated by true first farmers genes: it complicates the problem of classification


It's this study:

http://ac.els-cdn.com/S0960982209016947/1-s2.0-S0960982209016947-main.pdf?_tid=4cbb9e4e-6a43-11e3-964c-00000aacb35f&acdnat=1387632483_de9e8b5f85e80f8936c82a48bacac689

Pitted Ware Culture living in Gotland, compared to Gokhem Bell Beaker farmers.

epoch
26-12-13, 21:32
I'm trying to assimilate this new thread so I do just some remarks concerning my understanding of some points before doing more -
the female-male difference at some periods of possible new contacts between populations of different origins can have some importance: in history some rate of exchange of females between (new?) neighbouring populations seem checked - even after some generations of bipolar mixings some differences can remaind between two populations and the keeping on exchanges can yet send some differences between males and females "mean" autosomals...

Yeah. There always is the possibility that men brought the autosomal part in. Say, hired as warrior and rewarded with local women?

MOESAN
27-12-13, 00:49
Your point about the relationship between autosomal DNA and uniparental markers in an un unique individual is often lost sight of, but it is extremely important in my view.

However, even when looking at populations, or breeding groups, I think it's becoming more and more clear that uniparental markers are volatile and we can see big changes without changes of a proportionate size in the autosomal composition, and I think differential mating patterns, especially in terms of yDNA, founder effect and subsequent drift, selection for different mtDNA and yDNA subclades in the face of a changed climatic or personal environment, and also, (which is not often explored) sheer random chance, can affect the frequency of these uniparental markers. To the last point, a study was done of Icelandic mtDNA covering 300 years. No new geneflow, and yet because of the differential pattern of "daughtering out", certain sub-clades became rare, and others dominant. If anyone is interested, I'll try to find the site, but I'm not making it up!:)

I agree totally for the question of mt, Y and autosomals DNA respective rapports
concerning Iceland, i red this survey (or an abstract, rather) and yes, some precise subclades of mt-DNA HGs disappeaaed (very often the rarest ones) but the "big" HGs distribution was not too affected if I remember well - maybe on a largest range OF TIME or a smallest sample it could be more drastic?

Angela
29-12-13, 18:50
I agree totally for the question of mt, Y and autosomals DNA respective rapports
concerning Iceland, i red this survey (or an abstract, rather) and yes, some precise subclades of mt-DNA HGs disappeaaed (very often the rarest ones) but the "big" HGs distribution was not too affected if I remember well - maybe on a largest range OF TIME or a smallest sample it could be more drastic?


This is the Helgason 2009 paper on drift in Icelandic mtDNAm and how as a result, the mtDNA of the ancient samples was closer to that of the source populations than to that of modern Icelandic people. Unfortunately it's not the one to which I was referring, which I still can't find, but it's interesting none the less.
http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000343

The study to which I had referred had to do with statistical patterns over a smaller period. (I still haven't found it, Epoch.)

Generally, I think that selection is extremely important, particularly as it relates to mtDNA. I think the huge expansion of the "H" clades since the Neolithic is a big factor in the changed mtDNA map of Europe. Clearly, that has something to do with the expanding populations made possible by the agricultural revolution, but I think it's also partly a reflection of certain selective advantages in terms perhaps of climate adaptability, but also as regards disease protection and fertility, both in women who are mtDNA "H", and men who carry it.

I think I remember a study that found that mtDNA "H" provides an advantage in terms of resistance to infection...perhaps someone has a citation handy. At any rate, with all of the benefits of farming in terms of expanding populations (I think hunter-gatherers have spent most of history on the verge of extinction) raising domestic animals for food is a filthy business even today with our increased knowledge of the importance of sanitary conditions. MtDNA "H" as well as other mtDNA clades involved with the early development of animal husbandry might have increased resistance to diseases carried or spread by the animals. (Hasn't even tuberculosis been linked to transmission from animals? ) I've also wondered what effect that might have had in times of plague, not only Justinian's, but also the Black Death.

This is John Hawks' take on all of this:
http://johnhawks.net/weblog/reviews/genetics/mtdna_migrations/selection-mtdna-iceland-2009.html

In terms of the "Y", the other issue is fertility rates. I know I read something about reduced sperm motility in men carrying certain mtDNA clades.

MOESAN
29-12-13, 21:34
This is the Helgason 2009 paper on drift in Icelandic mtDNAm and how as a result, the mtDNA of the ancient samples was closer to that of the source populations than to that of modern Icelandic people. Unfortunately it's not the one to which I was referring, which I still can't find, but it's interesting none the less.
http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000343

The study to which I had referred had to do with statistical patterns over a smaller period. (I still haven't found it, Epoch.)

Generally, I think that selection is extremely important, particularly as it relates to mtDNA. I think the huge expansion of the "H" clades since the Neolithic is a big factor in the changed mtDNA map of Europe. Clearly, that has something to do with the expanding populations made possible by the agricultural revolution, but I think it's also partly a reflection of certain selective advantages in terms perhaps of climate adaptability, but also as regards disease protection and fertility, both in women who are mtDNA "H", and men who carry it.

I think I remember a study that found that mtDNA "H" provides an advantage in terms of resistance to infection...perhaps someone has a citation handy. At any rate, with all of the benefits of farming in terms of expanding populations (I think hunter-gatherers have spent most of history on the verge of extinction) raising domestic animals for food is a filthy business even today with our increased knowledge of the importance of sanitary conditions. MtDNA "H" as well as other mtDNA clades involved with the early development of animal husbandry might have increased resistance to diseases carried or spread by the animals. (Hasn't even tuberculosis been linked to transmission from animals? ) I've also wondered what effect that might have had in times of plague, not only Justinian's, but also the Black Death.

This is John Hawks' take on all of this:
http://johnhawks.net/weblog/reviews/genetics/mtdna_migrations/selection-mtdna-iceland-2009.html

In terms of the "Y", the other issue is fertility rates. I know I read something about reduced sperm motility in men carrying certain mtDNA clades.

Thanks
I red this survey but did not conserve it - I have to read it again, maybe was I wrong?
all the way, the sperm mobility is according to me of very light impact I explaoined that two times before answering to Maciamo - the mt DNA and the metabolic skills linked to it could very well undergo more severe selection, I agree - the very level distribution of mt DNA HGs in Europe even if subclades -differ, could be linked to a climatic/environmental pressure -
that said, when two populations living side by side and having had females or males exchanges between them are not completely evenly mixed and crossed it is of some interest to precise the sex of people studied even for mt DNA - have an happy and intellectually rich new year

adamo
29-12-13, 23:22
So basically he logs on; mentions sperm, and then wishes us to have "an happy and intellectually rich year". Anyone else feel the only point of that was mentioning sperm? XD! Perv lolll

Angela
30-12-13, 03:08
So basically he logs on; mentions sperm, and then wishes us to have "an happy and intellectually rich year". Anyone else feel the only point of that was mentioning sperm? XD! Perv lolll

Is this sort of childishness really necessary? Some of us haven't been in Middle School for quite a while. I think you owe Moesan, who makes very valuable contributions to this site, by the way, an apology.

Sile
30-12-13, 03:38
So basically he logs on; mentions sperm, and then wishes us to have "an happy and intellectually rich year". Anyone else feel the only point of that was mentioning sperm? XD! Perv lolll

last time I mentioned sperm and Ydna together Le brock jumped in saying no correlation, no this or no that

you might get a word from Le.B