Haplogroup I-M253, also known as I1, is a Y chromosomehaplogroup. The genetic markers confirmed as identifying I-M253 are the SNPs M253,M307.2/P203.2, M450/S109, P30, P40, L64, L75, L80, L81, L118, L121/S62, L123, L124/S64, L125/S65, L157.1, L186, and L187.[7] It is a primary branch of Haplogroup I-M170 (I*).
All known living members descend from a common ancestor 6 times younger than the common ancestor with I2.[1]
Before a reclassification in 2008,[22] the group was known as I1a, a name that has since been reassigned to a primary branch, haplogroup I-DF29. The other primary branches of I1 (M253) are I1b (S249/Z131) and I1c (Y18119/Z17925).
More than 99% of living men with I1 belong to the DF29 branch which is estimated to have emerged in 2400 BCE.[23][24] All DF29 men share a common ancestor born between 2500 and 2400 BCE.[25] The oldest ancient individual with I1-DF29 found is Oll009, a man from early Bronze Age Sweden.[26][27]
^Pedro Soares, Alessandro Achilli, Ornella Semino, William Davies, Vincent Macaulay, Hans-Jürgen Bandelt, Antonio Torroni, and Martin B. Richards, The Archaeogenetics of Europe, Current Biology, vol. 20 (February 23, 2010), R174–R183. yDNA Haplogroup I: Subclade I1, Family Tree DNA,
^Underhill PA, Myres NM, Rootsi S, Chow CT, Lin AA, Otillar RP, et al. (2007). "New phylogenetic relationships for Y-chromosome haplogroup I: reappraising its phylogeography and prehistory.". In Mellars P, Boyle K, Bar-Yosef O, Stringe C (eds.). Rethinking the Human Revolution. Cambridge, UK: McDonald Institute Monographs. pp. 33–42. ISBN978-1-902937-46-5.
^Lappalainen T, Hannelius U, Salmela E, von Döbeln U, Lindgren CM, Huoponen K, et al. (January 2009). "Population structure in contemporary Sweden—a Y-chromosomal and mitochondrial DNA analysis". Annals of Human Genetics. 73 (1): 61–73. doi:10.1111/j.1469-1809.2008.00487.x. PMID19040656. S2CID205598345.
^Dupuy BM, Stenersen M, Lu TT, Olaisen B (December 2006). "Geographical heterogeneity of Y-chromosomal lineages in Norway". Forensic Science International. 164 (1): 10–19. doi:10.1016/j.forsciint.2005.11.009. PMID16337760.