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View Full Version : Nordic Cluster L22 Uncommon in Denmark?



Dan Jensen
02-21-2020, 02:14 AM
Hi there. My Y-DNA is on an L22 branch:

L22 > Y3549 > CTS6868 > Z74 > CTS2208 > Y20287/8 > … > Y30548 > BY90649

My grandfather was born in Djursland, Jutland, Denmark, and nearly all of his ancestors going back 4-8 generations were also from the Djursland area. Grandpa Jensen was very Danish, but his Y-DNA is very Swedish. (I hear you: what's the difference?) Grandpa's haplogroup is 100% Danish (2 samples: haplopair?), but its parent clade Y30548 has only been found across the Kattegat in Halland, Sweden. Perhaps Grandpa's paternal line fled Halland 800 years ago or so.

But this is not a common pattern. What strikes me as odd is that I haven't found many other Danish L22s. I went through some FTDNA lists and found that lots of M253s sampled are Danish, so it's not as though Danes aren't represented in the I1 world, but a much smaller proportion of L22s are Danish. I found only 32 Danish L22 kits in all. Follow the above-listed SNP chain down to the very Finno-Swedish CTS2208, and I count only 3 Danes. One of those 3 is me, and another was nearly my grandfather's neighbor, with a genetic distance of only 4.

Dare I ask, are Danes just not very Nordic? ... Is Djursland a Swedish enclave?

Thanks,
Dan

spruithean
02-21-2020, 02:30 AM
The Kingdom of Denmark extended into southern Sweden and considering the history of Scandinavia it is not at all unusual that your haplogroup might have more northern matches.

mwauthy
02-21-2020, 08:28 PM
Hi there. My Y-DNA is on an L22 branch:

L22 > Y3549 > CTS6868 > Z74 > CTS2208 > Y20287/8 > … > Y30548 > BY90649

My grandfather was born in Djursland, Jutland, Denmark, and nearly all of his ancestors going back 4-8 generations were also from the Djursland area. Grandpa Jensen was very Danish, but his Y-DNA is very Swedish. (I hear you: what's the difference?) Grandpa's haplogroup is 100% Danish (2 samples: haplopair?), but its parent clade Y30548 has only been found across the Kattegat in Halland, Sweden. Perhaps Grandpa's paternal line fled Halland 800 years ago or so.

But this is not a common pattern. What strikes me as odd is that I haven't found many other Danish L22s. I went through some FTDNA lists and found that lots of M253s sampled are Danish, so it's not as though Danes aren't represented in the I1 world, but a much smaller proportion of L22s are Danish. I found only 32 Danish L22 kits in all. Follow the above-listed SNP chain down to the very Finno-Swedish CTS2208, and I count only 3 Danes. One of those 3 is me, and another was nearly my grandfather's neighbor, with a genetic distance of only 4.

Dare I ask, are Danes just not very Nordic? ... Is Djursland a Swedish enclave?

Thanks,
Dan


Denmark is underrepresented in the Ftdna database in proportion to their population size. With a population of around 5.6 million people only 606 people in the Ftdna database claim a Danish patrilineal origin. With a population of 10.1 million people there are 3,260 people in the Ftdna database that claim a Swedish patrilineal origin. Taking into account an almost 2 to 1 population ratio there is still a sampling bias of almost 3 to 1 between Sweden and Denmark. With over 30,000 kits, people with British Isles ancestry are heavily over sampled and are thus skewing the distributions.

Personally, I think I1 originated in Southern Sweden so I would expect the highest ratios to be from modern day Sweden even if certain areas of modern day Sweden were historically under Danish influence in the past. Even the oldest ancient fully I1 sample oll009 dated to be from 1930 BC - 1750 BC is from Öllsjö, Sweden.

Also, I believe the Danish tribes originated in the Scania and Kattegat/Baltic Sea regions and only invaded the Jutland Peninsula around 1500 years ago pushing the Angles and Saxons our of their native homelands. So I would expect many of the older I1 subclades such as L22 to have higher Swedish numbers.

Lastly, many people currently listed as I-M253 in the Ftdna database have only STR tested thus far and could potentially prove positive for L22 should they undergo further SNP testing.

Dan Jensen
02-24-2020, 12:56 AM
Thanks for the statistics lesson, mwauthy!

I took a more detailed look at FTDNA. Comparing their Denmark Project with their Sweden DNA Project, I see Sweden scoring roughly 4 times Denmark's L22 ("Nordic cluster") density. I suppose this is to be expected. At least Denmark is well within an order of magnitude, and with so few samples it's hard to expect precision.

I suppose my frustration is mostly due to a lack of quality Danish samples, as you suggested.

Detail:

I count 32 L22's in the Denmark DNA project, and I notice that 7 of those are estimates, so I believe the administrators of this project have made an effort to guess the L22's among M253's. That said, maybe some of the remaining M253's are L22's in disguise. Let's say there are 14 L22's hidden in the block of 66 M253's (index 61-74?). In addition, I see 8 M253's of questionable origin in the unsorted blocks toward the back. Maybe several of these turn out to be L22's. That adds up to maybe 48 L22's out of a total of 703 records. This gives me a rather optimistic 6.8% L22 in Denmark. Alternatively, if I settle for a more conservative estimate — say 34, the proportion is about 4.8%

When I look at the Sweden DNA Project, I see L22 start at index 624 and end end — I think — at 1747. That's 1124 records ... out of a total of 5147 records. That's 22% L22, roughly 4 times the percentage found in Denmark.

Thanks,
Dan


Denmark is underrepresented in the Ftdna database in proportion to their population size. With a population of around 5.6 million people only 606 people in the Ftdna database claim a Danish patrilineal origin. With a population of 10.1 million people there are 3,260 people in the Ftdna database that claim a Swedish patrilineal origin. Taking into account an almost 2 to 1 population ratio there is still a sampling bias of almost 3 to 1 between Sweden and Denmark. With over 30,000 kits, people with British Isles ancestry are heavily over sampled and are thus skewing the distributions.

Personally, I think I1 originated in Southern Sweden so I would expect the highest ratios to be from modern day Sweden even if certain areas of modern day Sweden were historically under Danish influence in the past. Even the oldest ancient fully I1 sample oll009 dated to be from 1930 BC - 1750 BC is from Öllsjö, Sweden.

Also, I believe the Danish tribes originated in the Scania and Kattegat/Baltic Sea regions and only invaded the Jutland Peninsula around 1500 years ago pushing the Angles and Saxons our of their native homelands. So I would expect many of the older I1 subclades such as L22 to have higher Swedish numbers.

Lastly, many people currently listed as I-M253 in the Ftdna database have only STR tested thus far and could potentially prove positive for L22 should they undergo further SNP testing.