 Before a reclassification in 2008, 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).According to a study published in 2010, I-M253 originated between 3,170 and 5,000 years ago, in Chalcolithic Europe.