Haplogroup M (mtDNA)

Haplogroup M
Possible time of origin	60,000 years before present
Possible place of origin	South Asia or Northeast Africa
Ancestor	L3
Descendants	M1, M2, M3, M4'45, M5, M6, M7, M8, M9, M10'42, M12'G, M13, M14, M15, M21, M27, M28, M29'Q, M31'32, M33, M34, M35, M36, M39, M40, M41, M44, M46, M47'50, M48, M49, M51, D
Defining mutations	263, 489, 10400, 14783, 15043

In , Haplogroup M is a (mtDNA) haplogroup. An enormous haplogroup spanning all the continents, the macro-haplogroup M, like its sibling N, is a descendant of haplogroup L3.

All mtDNA haplogroups considered native outside of Africa are descendants of either haplogroup M or its sibling haplogroup N. The geographical distributions of M and N are associated with discussions concerning out of Africa migrations and the subsequent colonization of the rest of the world. In particular, it is often taken to indicate that it is very likely that there was one particularly major prehistoric migration of humans out of Africa, and that both M and N were part of this colonization process.

There is a debate concerning geographical origins of Haplogroup M and its sibling haplogroup N. Both lineages are thought to have been the main surviving lineages involved in the out of Africa migration (or migrations) because all indigenous lineages found outside Africa belong to haplogroup M or haplogroup N. Yet to be conclusively determined is whether the mutations that define haplogroups M and N occurred in Africa before the exit from Africa or in Asia after the exit from Africa. Determining the origins of haplogroup M is further complicated by the fact that it is found in Africa and outside of Africa.

It is generally accepted that haplogroup M evolved shortly after the emergence of its parent clade haplogroup L3. Apart from haplogroup M and its sibling haplogroup N, the numerous other subclades of L3 are largely restricted to Africa, which suggests that L3 arose in Africa.

Much of discussion concerning the origins of haplogroup M has been related to its subclade haplogroup M1, which is the only variant of macrohaplogroup M found in Africa. Two possibilities were being considered as potential explanations for the presence of M1 in Africa:

In 2009, two independent publications reported a rare, deep-rooted subclade of haplogroup M, referred to as M23, that is present in Madagascar. The contemporary populations of Madagascar were formed in the last 2,000 years by the admixture of African and Southeast Asian (Austronesian) populations. M23 seems to be restricted to Madagascar as it was not detected anywhere else. M23 could have been brought to Madagascar from Asia where most deep rooted subclades of Haplogroup M are found.

According to this theory, anatomically modern humans carrying ancestral haplogroup L3 lineages were involved in the Out of Africa migration from East Africa into Asia. Somewhere in Asia, the ancestral L3 lineages gave rise to haplogroups M and N. The ancestral L3 lineages were then lost by genetic drift as they are infrequent outside Africa. The hypothesis of Asia as the place of origin of macrohaplogroup M is supported by the following:

...
Wikipedia