The following descriptions provide brief overviews of each haplogroup's origin and geographic distribution.
Haplogroup A was the first branch to split from the main tree. Almost all haplogroup As are from Africa. There, it is present in several populations at low frequency. A's highest frequency is in southern Africa.
Haplogroup B is one of the oldest human Y-chromosome lineages. Haplogroup B is found only in Africa. It was part of a major population expansion in Africa approximately 90-130 thousand years ago. This event may have spread Haplogroup B throughout Africa. Haplogroup B appears at low frequency all around Africa.
Haplogroup C originated in southern Asia and spread in all directions. This lineage colonized New Guinea, Australia, and north Asia, and currently is found with its highest diversity in populations of India. Haplogroup C is found throughout mainland Asia, the South Pacific, and at low frequency in Native American populations.
Haplogroup D is an old lineage that was born in Asia. Haplogroup D was later displaced from much of Asia by other colonizing groups, but is still present at intermediate frequencies in the aboriginal Japanese and on the Tibetan plateau. It is also found at low frequencies in Mongolia and in Central Asia.
Haplogroup E is one of the two branches of the mega-haplogroup DE. It originated approximately 50,000 years ago. Scientists believe that E arose in Africa. It may also represent a back migration. It is linked to the Neolithic expansion of peoples into Southern Europe. Scientists have discovered over sixty subclades of E.
The supergroup F is the parent haplogroup of G through T. Haplogroup F's other lineages are rare. They are distributed in Europe, the Middle East, and Asia.
Haplogroup G is a branch of the mega-haplogroup F. G is most common in Western Asia and the Caucasus. It has smaller numbers around the Mediterranean and eastward. G spread out from Western Asia in relatively recent historic times (the past few thousand years).
Haplogroup H is a branch of the mega-haplogroup F. H originated about 30,000 years ago in Eastern Africa. It spread to the Indian subcontinent. H is now found at high frequencies in India and Sri Lanka. It is also found in Romani populations.
Haplogroup I is a branch of the mega-haplogroup F and its subsequent mega-haplogroup IJ. I originated about 25,000 years ago among the people of Eastern Africa and Southern Europe. As the last ice age ended, it spread into Northern Europe.
Haplogroup J is a branch of the mega-haplogroup F and its subsequent mega-haplogroups IJK and IJ. J originated about 25,000 years ago in the Eastern Africa Levant. It has two main branches, J-M267 and J-M172. Both branches are found in Eastern African populations. It also spread into Europe and the Indian subcontinent during the Bronze Age.
J-M267 is the parent haplogroup of the Cohen Model Haplotype, CMH.
The K lineage is an old lineage presently found only at low frequencies in Africa, Asia, and in the south Pacific. One descendant line is restricted to Australia.
Haplogroup L is found primarily in India and Sri Lanka, and has also spread into Western Asia.
Haplogroup M is from the South Pacific. It was likely born in Melanesia. It then spread into Indonesia, Micronesia, and New Guinea.
Haplogroup N is a branch of the mega-haplogroup K. N originated about 10,000 years ago in Asia. Its branches have spread into East Asia and across Northern Europe.
Haplogroup O is a branch of the mega-haplogroup K. O originated about 35,000 years ago in Asia. Its branches have spread into Central and East Asia. O has around thirty known subclades.
Haplogroup Q is one of two branches of the mega-haplogroup P. Q originated about 20,000 years ago in Central Asia. Its branches have migrated into both Europe and East Asia.
Some of its branches took part in the settlement of the Americas. There, these branches make up the majority of pre-Columbian populations.
Haplogroup R is one of the two branches of the mega-haplogroup P. R originated about 30,000 years ago in Central Asia. It has two main branches, R-M173 and R-M479. R-M173 spread from Central Asia into Europe. Meanwhile, R-M479 spread east into the Indian subcontinent.
Migrations have brought both R-M173 and R-M479 branches (subclades) southward into the Eastern African Levant.
Haplogroup S is a branch of haplogroup K. It is from Southwestern Asia.
The haplogroup T lineage is an old lineage. It is found at low frequencies in Africa, Asia, and Europe.