Monday, August 6, 2018

two German Big Ys in the very Sardinian I-PF4190 branch: Updated I-CTS11338 tree

Click here to download our August 4, 2018 tree for I-CTS11338

If you look at this I-CTS11338 tree, you will see some of the biggest and best studied branches of I-M26.

P. Francalacci's 2013 study of 1200 Sardinian men found approximately 464 men who belonged to I-M26. And 346 of these men belonged to I-CTS11338. You will see several branches on this tree, but all 346 men belonged to the I-PF4190 branch. We represent these 346 anonymous Sardinian men by a single branch with no FTDNA kit number listed. The YFull tree shows only 7 of the 346 I-PF4190 Sardinan samples from Francalacci's study. To represent all the Y chromosome data sequenced by Francaclacci, we would need to add approximately 152 branches and hundreds of SNPs to our I-PF4190 tree.

At this point I consider I-PF4190 to be exactly equivalent to the main Sardinian expansion of I-M26. The slightly larger I-PF4189 group contains some major branches found only in Great Britain, so I-PF4189 can no longer be considered completely Sardinian. But I-PF4190 has four known immediate child branches, and these have all been found in Sardinia, and three of them are known only from Sardinia, and all of these branches had a rapid expansion in Sardinia.

This update shows a new branch called I-PF4432, it is represented by two Big Y results: one for a German man, and one for an American with likely German paternal ancestry from the 1700s. This tree shows several SNPs in red that are shared by the two men, some of these SNPs are also found in some of the 346 men from Francalacci's study.

It's difficult to represent all of the SNP data because there are so many Sardinian samples, and Francalacci's Y chromosome sequences are not exactly comparable to the Big Y sequences, different regions of the Y chromosome were sequenced and we do not have access to the Francalacci raw data.

But based on the number of unique novel variants in each man, the German and the German-American man have a common ancestor who lived approximately 2500 years ago, and their common ancestor with some of the men in Sardinia lived at approximately the same time.

The two German-ancestry men belong to a downstream branch of I-PF4190, and their branch is well within the population expansion in Sardinia. From Genographic 2.0 test results, we know about another German-American family that belongs to a different downstream branch of I-PF4190, and we know a few additional German families (and one Irish "Norman" family) that very likely belong to I-PF4190.

In most cases, the common ancestor between I-M26 men in Sardinia and I-M26 men in other parts of Europe lived 4500 years ago or longer. But in I-PF4190 we see these much closer relationships. Is this evidence for an "out of Sardinia" expansion, that we noticed several years ago with the first Geno 2.0 results? (click here). And is there some special connection to Germany?

Click here to find our previous tree for I-CTS11338

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