SwF is a cluster with ancestry on both sides the Gulf of Bothnia
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SwF was first identified by STR matches but recently a couple of BigY kits have made it possible to form a branch in the haplogroup tree defined by the SNP JN38/Y16813. Yfull currently displays two kits, at a new branch after I1-Z2337:
http://yfull.com/tree/I-Y16813/
A third BigY kit has just been completed (not at Yfull yet) and a fourth twig has been formed by testing of single SNPs at Yseq.
Explanation of time estimates
A 4100 years since the most recent common ancestor of all men being Z2337+, according to Yfull estimates.
B 750 years since the common ancestor in this split lived, according to Yfull estimates.
C 1350 years since the common ancestor of this split, roughly based on four more SNPs compared to split B and about 150 years per SNP.
D 300 years to common ancestor of split based on Yseq results on CombBED SNPs, JN41-, JN43+, JN44+, JN46+, JN47-. 2 of 5 SNPs are negative over 750 years, dating the split to roughly 300 ybp.
The ancestry of kit #298918 is known back to year 1800, Örnsköldsvik Sweden. The oldest known ancestor of kit #N136156 lived in Viborg, Finland in the late 19th century. Based on this knowledge it is not likely that the split occured less than 250 years ago.
Member of SSGG – Swedish Society for Genetic Genealogy
Link to FamilyTreeDNA project I1-Z2336(xL22,M227)
Link to local copy of Yseq data
Svenska 
English (UK)