Sampling Bias

mwauthy

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Location
California
Ethnic group
Namur Belgium and Quebec Canada
Y-DNA haplogroup
I-FT213710
mtDNA haplogroup
K2a6
Sweden: 1291/2850=45%, 10m
Norway: 579/1537=38%, 5m
Denmark: 202/555=36%, 6m
Iceland: 42/132=32%, 0.3m
Finland: 664/2421=27%, 6m
Netherlands: 229/983=23%, 17m
England: 2176/10996=20%, 55m
UK: 736/4127=18%, 66m
Germany: 1278/7326=17%, 83m
Scotland: 797/5835=14%, 5m
Wales: 126/922=14%, 3m
Belgium: 42/355=12%, 11m
Switzerland: 148/1255=12%, 8m
France: 245/2497=10%, 67m
Northern Ireland: 87/830=10%, 2m
Austria: 45/478= 9%, 9m
Ireland: 569/7767=7%, 5m
Poland: 173/2633=7%, 38m

I decided to include population totals to illustrate the sampling bias. Belgium has a slightly larger population than Sweden yet Sweden has 8 times as many samples. The British Isles has around 7 times the population of Belgium yet has 85 times as many samples. That’s a disproportionate sampling bias of 12 to 1. I believe that sampling bias is going to negatively influence any theories we have regarding subclade distribution and tying them to particular historical events.
 
I don't think the sampling biass is deliberate, but it is there.
The data that are available are being investigated.
And one must be aware that there are many dark spots.
 
Paradoxically, i feel prehistoric samples of Scandinavia are not very tested for Y-DNA. We have a lot of mtdna, but Motala aside, none of the samples are tested for y-dna and dont tell me they all are women or of low quality.
 
Paradoxically, i feel prehistoric samples of Scandinavia are not very tested for Y-DNA. We have a lot of mtdna, but Motala aside, none of the samples are tested for y-dna and dont tell me they all are women or of low quality.

All of the I1 ancient dna samples should be retested for deeper subclades to determine if they are extinct or extant branches on the I1 Haplotree. At the very least they should be retested for I-DF29 since they could easily be missing any of the 309 SNPs associated with modern I1.
 
All of the I1 ancient dna samples should be retested for deeper subclades to determine if they are extinct or extant branches on the I1 Haplotree. At the very least they should be retested for I-DF29 since they could easily be missing any of the 309 SNPs associated with modern I1.

The only I1 that we got from prehistoric eras ( and are we even sure they are? ) are from LBK Hungary.
 
The only I1 that we got from prehistoric eras ( and are we even sure they are? ) are from LBK Hungary.

Is it possible that the recent expansion of I1 started in Central Europe rather than Scandinavia? I haven't looked into this at all.
 
Is it possible that the recent expansion of I1 started in Central Europe rather than Scandinavia? I haven't looked into this at all.

My understanding is that the Hungary sample from the Neolithic tested positive for I-M253. However, I’m not sure how many of the other 308 SNPs associated with I1 it was tested for and whether or not this sample would be considered a direct ancestors to I1 or if it’s just one of the multitudes of branches that went extinct prior to a Scandinavian expansion.

Scandinavia was under ice during the last Ice Age so the ancestor of modern I1 would have originated farther south. The question is when did I1 enter Scandinavia? The earliest ancient samples from Scandinavia only date to the Nordic Bronze Age. I’m not even sure if these samples were tested for I1a (I-DF29) and if they are considered extinct or extant branches?
 
Sampling bias can be corrected for in calculations. Simply use a population factor. The number of samples in modern times certainly won't be indicative of ancient distribution. What we can do is retest older samples user better methods to get more SNPs, and factor the age of mutations along with historical migration patterns.

Many branches of I1-Z63 were in the eastern Germanic tribes but also in Anglo-Saxon England. With enough testing we can separate the ancient populations by identifiable SNPs. This will take many BigY samples but it's already bearing out in examples such as Iberian clades within the Z63 project.

Using the Z63 example, on each branch that was present in both East and West tribes, there will be a breaking SNP that isn't found in the other location. Both tribes had many subclades so it will be specific to each subclade regarding an East/West tribe split.

It will help I1 in particular to get more coverage in France somehow, and other "dark" zones. We need more Danish and German testers as well.
 
Is it possible that the recent expansion of I1 started in Central Europe rather than Scandinavia? I haven't looked into this at all.

I'm still waiting to know if the Hungarian LBK I* is ancestral or related with I1. Did we never had any confirmations?
 
My understanding is that the Hungary sample from the Neolithic tested positive for I-M253. However, I’m not sure how many of the other 308 SNPs associated with I1 it was tested for and whether or not this sample would be considered a direct ancestors to I1 or if it’s just one of the multitudes of branches that went extinct prior to a Scandinavian expansion.

Scandinavia was under ice during the last Ice Age so the ancestor of modern I1 would have originated farther south. The question is when did I1 enter Scandinavia? The earliest ancient samples from Scandinavia only date to the Nordic Bronze Age. I’m not even sure if these samples were tested for I1a (I-DF29) and if they are considered extinct or extant branches?

The earliest samples from Scandinavia are from Mesolithic. Hummerwidkomen ( something like that ) from Norway dated from 7500-7300 BC was I2. Motala individuals in Sweden dated from 6000-5500 BC were I2a1, I2a1b and I2c2. And 7000 BC from Gotland was I2. But from all the Neolithic and Corded Ware Scandinavians we dont have any y-dna, wich i found highly suspicious. Who cares about Mesolithic? It's like having Paleolithic and Mesolithic samples from everywhere, but barely none Roman and absolutely any Etruscans samples. Why the most important ones for direct history seems to be never be take into account?
 
I'm still waiting to know if the Hungarian LBK I* is ancestral or related with I1. Did we never had any confirmations?
I suspect you'll be waiting a long time. I've not seen any plans to retest BAB5. The single SNP M253 remains the only relevant SNP. I wish we could get this done

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