Below are brief descriptions of the major mitochondrial haplogroups.
Haplogroup A is found in Indigenous Americans as well as Asians. Members of this group crossed the Beringian land bridge into North America during the Ice Age.
Haplogroup B is one of the principal East Asian lineages. Members of Haplogroup B also migrated to the Americas between 15 and 20 thousand years ago, becoming one of five mitochondrial lineages identified among Indigenous Americans.
Haplogroup C is a descendant of haplogroup M, one of the two major lineages that migrated out of Africa to populate the rest of the world. It is currently found in northeast Asia, and it is considered one of the founding lineages of the Indigenous American population.
Haplogroup D is the principal East Asian lineage. Notable subgroups include D4, which is prevalent among Central Asian peoples, and D1, which is one of the five haplogroups represented among Indigenous Americans.
Haplogroup E likely arose within the vicinity of northeast Sundaland (Eastern Malaysia) and spread throughout the islands of Southeast Asia, where various sublineages flourished 5-10,000 years ago.
Haplogroup F arose in Central Asia and spread rapidly eastward to become one of the primary mitochondrial lineages in East and Southeast Asia. Its greatest frequency and sequence diversity can be found among coastal Asian populations.
Haplogroup H is the most frequently found haplogroup throughout Eurasia. Following the Last Glacial Maximum about 20,000 years ago, peoples of haplogroup H dominated the population expansion of Europe. The results are this group’s uniform distribution throughout Europe.
Haplogroup HV is the ancestral haplogroup to H and V, which dominate the western European lineages today. About 75% of the western European population descends from this haplogroup.
Haplogroup I is widespread throughout Europe, although at relatively low levels (about 2%). It is also found in western Eurasia, and it is believed that early members of haplogroup I moved north across the Caucasus to carry their lineage into Europe during the Old Stone Age.
Haplogroup J is one of the four major European-specific haplogroups. It is believed that the spread of haplogroup J into Europe was brought by the first farming and herding societies from Western Asia during Neolithic times (New Stone Age).
Haplogroup K originated in western Asia and spread throughout Europe. Certain lineages are also found in Central Asia and Northern Africa. It is known for its presence in distinct population groups, such as the prehistoric Basques and the Ashkenazi Jews.
Haplogroup L0 is the most ancient haplogroup on the human mtDNA tree. L0 arose about 150,000 years ago in eastern Africa, where the oldest fossils of anatomically modern humans have been found. L0a arose 100,000 years later and was carried to the southeastern part of the continent.
Haplogroup L1 is one of the oldest branches of the maternal family tree, a daughter of the mitochondrial Eve and sister to L0. It is most frequently found in western and central sub-Saharan Africa, and seldom appears in eastern or southern Africa. L1 gave rise to branches L2–L6, with L3 giving rise to all the non-African haplogroups found today.
Haplogroup L2 is a direct descendant of the mitochondrial Eve. It is currently found in 1/3 of sub-Saharan Africans, and its subgroup L2a is the most common mtDNA haplogroup among African Americans.
Haplogroup L3 a daughter of the mitochondrial Eve, was one of the first groups of humans to venture out of Africa, eventually populating the rest of the world. Asian and European haplogroups trace their ancestry to L3.
Haplogroup M members were among the first humans to leave Africa, migrating east along the southern coasts of Asia. Subgroup M1 intrigues scientists with its presence in East Africa; another subgroup, M3, is believed to be native to India.
Haplogroup N is one of the two major lineages from which non-African haplogroups descend. Today, members of this haplogroup are found in many continents around the world.
Haplogroup R is ancient and complex; today its members can be found all over the world. Originating in the Near East, members of haplogroup R spread into Africa, southwestern Eurasia, the Middle East, and Central and South Asia.
Haplogroup T a relatively young haplogroup, is considered a founding lineage of the Neolithic period, when humans were living.
Haplogroup U is one of the Europe’s oldest and most diverse haplogroups: it predates the expansion of agriculture in Europe. About 10-11% of Europeans and European Americans belong to this haplogroup.
Haplogroup V is a European haplogroup that arose in Iberia (Spain) towards the end of the Ice Age, and spread east and north during the repopulation of Europe.
Haplogroup W is still commonly found in its place of origin, although it is also found in love levels across Eurasia. It is associated with the appearance of the Aurignacian culture during the Upper Paleolithic.
Haplogroup X arose in Southwest Asia, and from there spread to Europe, North Africa, and the Near East. Its subgroup X2 is one of the founding lineages of Indigenous Americans.
Haplogroup Y is associated with Siberian populations, and it is also fond in Japanese, Korean, and some Southeast Asian populations.
Haplogroup Z is found throughout Asia, with higher levels found in Tibet and Siberia, and lower levels in Japan. A subgroup, Z1, is also found among the Finnish Saami, which are thought to have both European and Asian ancestry.