Yng nghyd-destun tarddiad bodau dynol yn Affricana, mae'r senario Gwasgariad Deheuol (neu Wasgariad y De; neu weithiau: yr ymfudoarfordirol mawr) yn cyfeirio at y mudo cynnar ar hyd arfordir deheuol Asia, o benrhyn Arabia trwy Persia (Iran heddiw) ac India i Dde-ddwyrain Asia ac Oceania.[1] Gwladychodd disgynyddion diweddarach y mudwyr hyn, yn y pen draw, weddill Ewrasia, gweddill Oceania, a'r Americas. .
Trosolwg o boblogaeth dynol cynnar a sut yr ymfudodd yn ystod y Paleolithig Uchaf, yn dilyn patrwm 'Gwasgariad y De'.
Mae'n gysylltiedig â phresenoldeb a gwasgariad grwp-haplo MtDNA M a haplogroup N, yn ogystal â phatrymau dosbarthiad penodol grwp-haplo Y-DNA F (cyndadau O, N, R, Q),[7] grwp-haplo C a grwp-haplo D, yn y rhanbarthau hyn.[8][9]
Mae’r ddamcaniaeth yn cynnig bod bodau dynol cynnar y cyfnod modern, rhai o gludwyr grwp-haplo mitocondriaidd L3, wedi cyrraedd penrhyn Arabia tua 70,000-50,000 o flynyddoedd yn ôl, gan groesi o Ddwyrain Affrica ar hyd culfor Bab-al-Mandab. Amcangyfrifwyd poblogaeth o 2,000 i 5,000 o unigolion yn Affrica, ac mai dim ond grŵp bach, o bosibl cyn lleied â 150 i 1,000 o bobl, a groesodd y Môr Coch.[10] Byddai’r grŵp wedi teithio ar hyd y llwybr arfordirol o amgylch Arabia a Phersia i India yn gymharol gyflym, o fewn ychydig filoedd o flynyddoedd. O India, byddent wedi lledu i Dde-ddwyrain Asia ("Sundaland") ac Oceania ("Sahul").[3][4][6]
↑Phillip Endicott; Mait Metspalu; Toomas Kivisild (2007), The Evolution and History of Human Populations in South Asia: Inter-disciplinary Studies in Archaeology, Biological Anthropology, Linguistics and Genetics, Springer Netherlands, doi:10.1007/1-4020-5562-5_10, ISBN978-1-4020-5561-4, "... The concept of a coastal migration was already envisioned in 1962 by the ..."
↑Kevin O. Pope; John E. Terrell (9 October 2007), "Environmental setting of human migrations in the circum-Pacific region", Journal of Biogeography35 (1): 071009214220006––, doi:10.1111/j.1365-2699.2007.01797.x, "... The expansion of modern humans out of Africa, following a coastal route into southern Asia, was initially thwarted by a series of large and abrupt environmental changes. A period of relatively stable climate and sea level from c. 45,000 yr bp to 40,000 yr bp supported a rapid coastal expansion of modern humans throughout much of Southeast Asia, enabling them to reach the coasts of northeast Russia and Japan by 38,000–37,000 yr bp ..."
↑ 3.03.1Spencer Wells (2002), The Journey of Man: A Genetic Odyssey, Princeton University Press, ISBN978-0691115320, https://books.google.com/books?id=WAsKm-_zu5sC, "... the population of south-east Asia prior to 6000 years ago was composed largely of groups of hunter-gatherers very similar to modern Negritos ... So, both the Y-chromosome and the mtDNA paint a clear picture of a coastal leap from Africa to south-east Asia, and onward to Australia ... DNA has given us a glimpse of the voyage, which almost certainly followed a coastal route via India ..."Gwall cyfeirio: Tag <ref> annilys; mae'r enw "wells2002" wedi'i ddiffinio droeon gyda chynnwys gwahanol
↑ 4.04.1"Pleistocene Mitochondrial Genomes Suggest a Single Major Dispersal of Non-Africans and a Late Glacial Population Turnover in Europe". Current Biology26 (6): 827–833. 2016. doi:10.1016/j.cub.2016.01.037. PMID26853362.Gwall cyfeirio: Tag <ref> annilys; mae'r enw "Posth" wedi'i ddiffinio droeon gyda chynnwys gwahanol
↑"The Genographic Project: Genetic Markers, Haplogroup D (M174)", National Geographic, 2008, https://www3.nationalgeographic.com/genographic/atlas.html, "... Haplogroup D may have accompanied another group, the Coastal Clan (haplogroup C) on the first major wave of migration out of Africa around 50,000 years ago. Taking advantage of the plentiful seaside resources, these intrepid explorers followed the coastline of Africa through the southern Arabian Peninsula, India, Sri Lanka, and Southeast Asia. Alternatively, they may have made the trek at a later time, following in the footsteps of the Coastal Clan ..."