The following descriptions provide brief overviews of each haplogroup’s origin and geographic distribution.
Haplogroup A is the first Y-chromosome lineage to diverge, from which all Y-branches are descended. Haplogroup A is restricted to Africa, where it is present in several populations at low frequency but is most commonly found in populations of the Koi and the San tribes of Southern Africa. Early sub-branches of A have been found in central Africa.
Haplogroup B is one of the oldest Y-chromosome lineages in humans. Haplogroup B is found almost exclusively in Africa. This lineage was likely the first to disperse around Africa approximately 90-130 thousand years ago. Haplogroup B appears at low frequency all around Africa but is at its highest frequency in Pygmy populations.
Haplogroup C is found throughout mainland Asia, the south Pacific, New Guinea, Australia, and at low frequencies in Native American populations.
Haplogroup D evolved in Asia. This Haplogroup 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 Mongolian populations and the Altais people of central Asia.
Haplogroup E is an African lineage. It is currently believed that this haplogroup dispersed south from northern Africa with the Bantu agricultural expansion. E is also the most common lineage among African Americans. It is a diverse haplogroup with many branches and is found distributed throughout Africa today. It is also found at a very low frequency in North Africa and the Middle East.
Haplogroup F is the parent haplogroup of branches G through T. F lineages are extremely rare and are distributed in Europe, the Middle East, and Asia. Future work will better resolve the distribution and historical characteristics of this haplogroup.
Haplogroup G was the first branch of Haplogroup F outside of Africa. G is found mostly in the north central Middle East and the Caucasus, with smaller numbers around the Mediterranean and eastward. Haplogroup G represents one of the first peoples in Europe.
Haplogroup H is nearly completely restricted to India, Indonesia, Sri Lanka, and Pakistan.
Haplogroup I dates to 23,000 years ago or older. This haplogroup is found throughout Europe, although some branches may be present in low frequencies in Northeast Africa, Central Siberia, the Near East, and the Caucasus regions. Haplogroup I represents one of the first peoples in Europe.
Haplogroup J is found at highest frequencies in the Middle East, west of the Zagros Mountains in Iran to the Mediterranean Sea, and encompassing the entire Arabian Peninsula. It is also found in north African populations where it has been carried by Middle Eastern traders into Europe, central Asia, India, and Pakistan.
The Cohen Modal Haplotype (CMH) lineage as well as the presumed lineage of the Prophet Mohammed are found in Haplogroup J-M267.
The K lineage is presently found at low frequencies in Africa, Asia, and in the south Pacific. One descendent line of this lineage is restricted to aboriginal Australians while another is found at low frequency in southern Europe, Northern Africa, and the Middle East.
Haplogroup L is found primarily in India and Sri Lanka and has also spread into several Middle Eastern populations (Turks, Saudis, and Pakistanis). It is also found at very low frequencies in Europe.
Haplogroup M is completely confined to the South Pacific. It most probably originated in Melanesia and then spread into Indonesia, Micronesia, and New Guinea.
Haplogroup N is distributed throughout Northern Eurasia and Siberia. It is the most common Y-chromosome type in Uralic speakers (Finns and Native Siberians). It is also found in Mongolia.
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 P is an extremely rare haplogroup at this time. It is the ancestral line to haplogroups Q and T. It is found at low frequency in India, Pakistan, and central Asia.
Haplogroup Q is the lineage that links Asia and the Americas. This lineage is found in North and Central Asian populations as well as native Americans. Among European populations, haplogroup Q is most frequently found in Eastern Europe and Scandinavia. This lineage is believed to have originated in Central Asia and migrated through the Altai/Baikal region of northern Eurasia into the Americas.
Haplogroup Q-M3 is the only lineage strictly associated with native American populations. This haplogroup is defined by the presence of the M3 mutation which occurred on the Q lineage 8-12 thousand years ago as the migration into the Americas was underway.
Haplogroup R originated in Central Asia. Most descendants belong to one of two major lineages. They are present at low frequencies across Central Asia, South Asia, and Europe. Haplogroup R-M173 possibly originated in eastern Europe and then migrated eastward into Asia.
Haplogroup S-M230 is an Oceanic lineage and is found primarily in populations in Papau New Guinea with lower frequencies in Melanisia and Indonesia.
Haplogroup T is presently found in southern Europe, Northern Africa, and the Middle East. President Thomas Jefferson, formerly of Wales, was Haplogroup T.