Haplogroups / Paternal line
I1
The Scandinavian line
The story of this line
I-M253 is striking because its branch is ancient while every living carrier descends from one man who lived only around four and a half thousand years ago. Something reduced this line to a very small number of men and it then expanded rapidly. It peaks in Sweden and Norway and was carried outward along Norse routes.
What it traces
I1 sits on the family tree of the Y chromosome, passed from father to son. Following it back means following your father, his father, and so on back, one unbroken thread. It says nothing about the thousands of other ancestors you had at the same depth, which is the single most common misunderstanding about haplogroups.
The route, roughly
- East African Rift about 150 thousand years ago
- Horn of Africa about 70 thousand years ago
- Arabian peninsula about 62 thousand years ago
- The Levant about 35 thousand years ago
- The Balkans about 28 thousand years ago
- Scandinavia about 4.6 thousand years ago
- Atlantic Europe about 1.2 thousand years ago
A route drawn from where the branch arose and where it is found today. It is the path of one thread through your ancestry, not a map of where your family as a whole came from.
Is I1 your haplogroup?
If you have taken a test with 23andMe, AncestryDNA, MyHeritage, Family Tree DNA, TellMeGen or Living DNA, the answer is already sitting in the raw data file they gave you. You do not need another test.
Sequencings reads the file in your browser. It is never uploaded, and you can confirm that in your browser’s network tab while it happens.
Common questions
What is haplogroup I1?
I1 is a branch of the human paternal family tree, traced through the Y chromosome, passed from father to son. I-M253 is striking because its branch is ancient while every living carrier descends from one man who lived only around four and a half thousand years ago. Something reduced this line to a very small number of men and it then expanded rapidly. It peaks in Sweden and Norway and was carried outward along Norse routes.
How old is haplogroup I1?
It first appeared about 4,600 years ago for every man alive who carries it, in Scandinavia and northern Europe. That is a coalescence estimate with a wide margin, not a date.
How do I find out if I1 is my haplogroup?
If you have taken a home DNA test, the answer is already in the raw data file you were given. Sequencings reads that file in your browser and traces both lines without uploading anything.
Does haplogroup I1 tell me about my health?
No. Haplogroups describe one line of descent. They are not used to assess health risk, and anyone who tells you otherwise is overreaching.
Sources
ISOGG Y-DNA Haplogroup Tree, marker coordinates via ybrowse.org (hg19).