Haplogroup N is a human mitochondrial DNA (mtDNA) clade. A macrohaplogroup, its descendant lineages are distributed across many continents. Like its sibling macrohaplogroup M, macrohaplogroup N is a descendant of the haplogroup L3.
All mtDNA haplogroups found outside of Africa are descendants of either haplogroup N or its sibling haplogroup M. M and N are the signature maternal haplogroups that define the theory of the recent African origin of modern humans and subsequent early human migrations around the world. The global distribution of haplogroups N and M indicates that there was likely at least one major prehistoric migration of humans out of Africa, with both N and M later evolving outside the continent.[7]
Origins
There is widespread agreement in the scientific community concerning the African ancestry of haplogroup L3 (haplogroup N's parent clade).[13] However, whether or not the mutations which define haplogroup N itself first occurred within Asia or Africa has been a subject for ongoing discussion and study.[13]
The out of Africa hypothesis has gained generalized consensus. However, many specific questions remain unsettled. To know whether the two M and N macrohaplogroups that colonized Eurasia were already present in Africa before the exit is puzzling.
Torroni et al. 2006 state that Haplogroups M, N and R occurred somewhere between East Africa and the Persian Gulf.[14]
Also related to the origins of haplogroup N is whether ancestral haplogroups M, N and R were part of the same migration out of Africa, or whether Haplogroup N left Africa via the Northern route through the Levant, and M left Africa via Horn of Africa. This theory was suggested because haplogroup N is by far the predominant haplogroup in Western Eurasia, and haplogroup M is absent in Western Eurasia, but is predominant in India and is common in regions East of India. However, the mitochondrial DNA variation in isolated "relict" populations in southeast Asia and among Indigenous Australians supports the view that there was only a single dispersal from Africa. Southeast Asian populations and Indigenous Australians all possess deep rooted clades of both haplogroups M and N.[15] The distribution of the earliest branches within haplogroups M, N, and R across Eurasia and Oceania therefore supports a three-founder-mtDNA scenario and a single migration route out of Africa.[16] These findings also highlight the importance of Indian subcontinent in the early genetic history of human settlement and expansion.[17]
Asian origin hypothesis
The hypothesis of Asia as the place of origin of haplogroup N is supported by the following:
Haplogroup N is found in all parts of the world but has low frequencies in Sub-Saharan Africa. According to a number of studies, the presence of Haplogroup N in Africa is most likely the result of back migration from Eurasia.[6]
The oldest clades of macrohaplogroup N are found in Asia and Australia.
It would be paradoxical that haplogroup N had traveled all the distance to Australia or New World yet failed to affect other populations within Africa besides North Africans and Horn Africans.
The mitochondrial DNA variation in isolated "relict" populations in southeast Asia supports the view that there was only a single dispersal from Africa.[15] The distribution of the earliest branches within haplogroups M, N, and R across Eurasia and Oceania provides additional evidence for a three-founder-mtDNA scenario and a single migration route out of Africa.[16] These findings also highlight the importance of Indian subcontinent in the early genetic history of human settlement and expansion.[17] Therefore, N's history is similar to M and R which have their most probable origin in South Asia.
A study (Vai et al. 2019), finds a basal branch of maternal haplogroup N in early Neolithic North African remains from the Libyan site of Takarkori. The authors propose that N most likely split from L3 in the Arabian peninsula and later migrated back to North Africa, with its sister haplogroup M also likely splitting from L3 in the Middle East, but also suggest that N may have possibly diverged in North Africa, and state that more information is necessary to be certain.[3]
African origin hypothesis
According to Toomas Kivisild "the lack of L3 lineages other than M and N in India and among non-African mitochondria in general suggests that the earliest migration(s) of modern humans already carried these two mtDNA ancestors, via a departure route over the Horn of Africa.[9]
In 2019, a study by Vai et al. presented evidence of a basal branch of haplogroup N from the Neolithic Sahara. They suggest that N either diverged from haplogroup L3 in the Near East (possibly in the Arabian peninsula, following the exit of L3 from Africa), then back-migrated to North Africa, or that it instead may have originated in North Africa (having diverged from L3 there).[3]
Distribution
Haplogroup N is derived from the ancestral L3 macrohaplogroup, which represents the migration discussed in the theory of the recent African origin of modern humans. Haplogroup N is the ancestral haplogroup to almost all clades today distributed in Europe and Oceania, as well as many found in Asia and the Americas. It is believed to have arisen at a similar time to haplogroup M.
Subgroups distribution
Haplogroup N's derived clades include the macro-haplogroup R and its descendants, and haplogroups A, I, S, W, X, and Y.
Rare unclassified haplogroup N* has been found among fossils belonging to the Cardial and Epicardial culture (Cardium pottery) and the Pre-Pottery Neolithic B.[18] A rare unclassified form of N has been also been reported in modern Algeria.[19]
Haplogroup N1a – Arabian Peninsula and Northeast Africa.[8] Found also in Central Asia and Southern Siberia.[22] This branch is well attested in ancient people from various cultures of Neolithic Europe, from Hungary to Spain,[23] and among the earliest farmers of Anatolia.[24]
Haplogroup N9a6 – Thailand (Phuan from Lopburi Province,[32]Khon Mueang from Lamphun Province,[32]Phutai from Sakon Nakhon Province,[32]Lawa from Mae Hong Son Province,[32] Soa from Sakon Nakhon Province[32]), Vietnam, Sumatra [TMRCA 11,972.5 ± 5,491.7 ybp; CI=95%[31]]
Haplogroup N9a9 – Chelkans (Biyka, Turochak), Tubalar (North-East Altai), Kyrgyz (Kyrgyzstan), China, Ukraine (Vinnytsia Oblast), Romania (10th century AD Dobruja)
Haplogroup N9a10 – Thailand (Khon Mueang from Mae Hong Son Province, Chiang Mai Province, Lamphun Province, and Lampang Province,[32]Shan from Mae Hong Son Province,[32]Lao Isan from Loei Province,[32]Black Tai from Kanchanaburi Province,[32]Phuan from Sukhothai Province and Phichit Province,[32]Mon from Kanchanaburi Province[32]), Laos (Lao from Luang Prabang,[32]Hmong[34]), Vietnam (Tay Nung), China (incl. Han in Chongqing)
Haplogroup N10 – found in China (Han from Shanghai, Jiangsu, Fujian, Guangdong, and Yunnan, Hani and Yi from Yunnan, She from Guizhou, Uzbek from Xinjiang) and Southeast Asia (Thailand, Indonesia, Vietnam, Malaysia).[30]
Haplogroup N11 – Mainland China & Philippines: Han Chinese (Yunnan, Sichuan, and Hubei), Tibetan (Xizang), Dongxiang (Gansu), Oroqen (Inner Mongolia) and Mamanwa (Philippines).[30][43]
Haplogroup X[50] – found most often in Western Eurasia, but also present in the Americas.[20]
Haplogroup X1 – found primarily in North Africa as well as in some populations of the Levant, notably among the Druze
Haplogroup X2 – found in Western Eurasia, Siberia and among Native Americans
Haplogroup R[51] – a very extended and diversified macro-haplogroup.
Subclades
Tree
This phylogenetic tree of haplogroup N subclades is based on the paper by Mannis van Oven and Manfred Kayser Updated comprehensive phylogenetic tree of global human mitochondrial DNA variation[12] and subsequent published research.
^Richards, Martin; Bandelt, Hans-Jürgen; Kivisild, Toomas; Oppenheimer, Stephen (2006). "A Model for the Dispersal of Modern Humans out of Africa". In Bandelt, Hans-Jürgen; Macaulay, Vincent; Richards, Martin (eds.). Human Mitochondrial DNA and the Evolution of Homo sapiens. Nucleic Acids and Molecular Biology. Vol. 18. pp. 225–65. doi:10.1007/3-540-31789-9_10. ISBN978-3-540-31788-3. subclades. L3b d, L3e and L3f, for instance, are clearly of African origin, whereas haplogroup N is of apparently Eurasian origin
^ abOlivieri, A.; Achilli, A.; Pala, M.; Battaglia, V.; Fornarino, S.; Al-Zahery, N.; Scozzari, R.; Cruciani, F.; Behar, D. M.; Dugoujon, J.-M.; Coudray, C.; Santachiara-Benerecetti, A. S.; Semino, O.; Bandelt, H.-J.; Torroni, A. (2006). "The mtDNA Legacy of the Levantine Early Upper Palaeolithic in Africa". Science. 314 (5806): 1767–70. Bibcode:2006Sci...314.1767O. doi:10.1126/science.1135566. PMID17170302. S2CID3810151. The scenario of a back-migration into Africa is supported by another feature of the mtDNA phylogeny. Haplogroup M's Eurasian sister clade, haplogroup N, which has a very similar age to M and no indication of an African origin
^Torroni, A; Achilli, A; MacAulay, V; Richards, M; Bandelt, H (2006). "Harvesting the fruit of the human mtDNA tree". Trends in Genetics. 22 (6): 339–45. doi:10.1016/j.tig.2006.04.001. PMID16678300.
^A. Stevanovitch; A. Gilles; E. Bouzaid; R. Kefi; F. Paris; R. P. Gayraud; J. L. Spadoni; F. El-Chenawi; E. Béraud-Colomb (January 2004). "Mitochondrial DNA Sequence Diversity in a Sedentary Population from Egypt". Annals of Human Genetics. 68 (1): 23–39. doi:10.1046/j.1529-8817.2003.00057.x. PMID14748828. S2CID44901197.
^ abcHwan Young Lee, Ji-Eun Yoo, Myung Jin Park, Ukhee Chung, Chong-Youl Kim, and Kyoung-Jin Shin, "East Asian mtDNA haplogroup determination in Koreans: Haplogroup-level coding region SNP analysis and subhaplogroup-level control region sequence analysis." Electrophoresis (2006). doi:10.1002/elps.200600151.
^Wibhu Kutanan, Rasmi Shoocongdej, Metawee Srikummool, et al. (2020), "Cultural variation impacts paternal and maternal genetic lineages of the Hmong-Mien and Sino-Tibetan groups from Thailand." European Journal of Human Genetics. https://doi.org/10.1038/s41431-020-0693-x
^Hongbin Yao, Mengge Wang, Xing Zou, et al., "New insights into the fine-scale history of western-eastern admixture of the northwestern Chinese population in the Hexi Corridor via genome-wide genetic legacy." Mol Genet Genomics 2021 Mar 1. doi: 10.1007/s00438-021-01767-0.