Recent African origin of modern humans
In paleoanthropology, the recent African origin of modern humans, also called the "Out of Africa" theory (OOA), the "recent single-origin hypothesis" (RSOH), "replacement hypothesis," or "recent African origin model" (RAO), is the most widely accepted model of the geographic origin and early migration of anatomically modern humans. The theory argues for the African origins of modern humans, who left Africa in a single wave of migration which populated the world, replacing older human species.
A first dispersal took place between 130,000–115,000 years ago via northern Africa, but died out or retreated, though Chinese researchers question this extinction and claim the presence of modern humans in China at least 80,000 years ago. A second dispersal took place via the so-called Southern Route, which followed the southern coastline of Asia, and colonized Australia by around 50,000 years ago. Europe was populated by an early offshoot which settled the Near East and Europe (post-Toba hypothesis).
The major competing hypothesis of the single origin theory is the multiregional origin of modern humans, which envisions a wave of Homo sapiens migrating earlier from Africa and interbreeding with local Homo erectus populations in multiple regions of the globe.
- 1 Early Homo sapiens
- 2 Movement out of Africa
- 3 Genetic reconstruction
- 4 History of the theory
- 5 Competing hypotheses
- 6 See also
- 7 Notes
- 8 References
- 9 Sources
- 10 Further reading
- 11 External links
Early Homo sapiens
Anatomically modern humans originated in Africa about 250,000 years ago. The trend in cranial expansion and the acheulean elaboration of stone tool technologies which occurred between 400,000 years ago and the second interglacial period in the Middle Pleistocene (around 250,000 years ago) provide evidence for a transition from H. erectus to H. sapiens. In the Recent African Origin (RAO) scenario, migration within and out of Africa eventually replaced the earlier dispersed H. erectus.
Beginning about 100,000 years ago evidence of more sophisticated technology and artwork begins to emerge and by 50,000 years ago fully modern behaviour becomes more prominent. Stone tools show regular patterns that are reproduced or duplicated with more precision while tools made of bone and antler appear for the first time.
Fossil finds outside Africa
Fossils of early Homo sapiens were found in Qafzeh cave in Israel and have been dated to 80,000 to 100,000 years ago. A fossil of a modern human dated to 54,700 years ago was found in Manot Cave in Israel, named Manot 1, though the dating was questioned by Groucutt et al. (2015). Fossils from Lake Mungo, Australia have been dated to about 42,000 years ago. The Tianyuan cave remains in China's Liujiang region have a probable date range between 38,000 and 42,000 years ago. The Tianyuan specimens are most similar in morphology to Minatogawa Man, modern humans dated between 17,000 and 19,000 years ago and found on Okinawa Island, Japan.
Movement out of Africa
The first dispersal took place between 130,000–115,000 years ago via northern Africa, but died out or retreated. Chinese researchers question this extinction, claiming that modern humans were present in China already 80,000 years ago.
A second dispersal took place via the so-called Southern Route, either before or after the Toba event, which happened between 69,000 and 77,000 years ago. This dispersal followed the southern coastline of Asia, crossing about 250 kilometres (155 mi) of sea, and colonized Australia by around 50,000 years ago. According to this theory, Europe was populated either by a migration out of India, which was repopulated from southeast Asia after the Toba-event (pre-Toba hypothesis), or by an early offshoot which settled the Near East and Europe (post-Toba hypothesis).
Early northern Africa dispersal
The early northern Africa dispersal took place between 130,000–115,000 years ago. The discovery of stone tools in the United Arab Emirates in 2011 indicated the presence of modern humans between 100,000 and 125,000 years ago. An increasing number of researchers think that "long-neglected North Africa" may have been the original home of the first modern humans to migrate out of Africa.
Fossils of early Homo sapiens were found in Qafzeh cave in Israel and have been dated to 80,000 to 100,000 years ago. These humans seem to have either become extinct or retreated back to Africa 70,000 to 80,000 years ago, possibly replaced by southbound Neanderthals escaping the colder regions of ice age Europe. Hua Liu et al. analyzed autosomal microsatellite markers dates to c. 56,000±5,700 years ago mtDNA evidence. He interprets the paleontological fossil of early modern human from Qafzeh cave as an isolated early offshoot that retracted back to Africa.
According to Kuhlwilm et al. (2016) Altai Neaderthalers received gene flow from modern humans circa 100,000 years ago, from humans which split off from other modern humans circa 200,000 years ago. Kuhlwilm et al. conclude that "the ancestors of Neanderthals from the Altai Mountains and early modern humans met and interbred, possibly in the Near East, many thousands of years earlier than previously thought." According to co-author Ilan Gronau, "this actually complements archaeological evidence of the presence of early modern humans out of Africa around and before 100 ka by providing the first genetic evidence of such populations."
Chinese research questions the extinction of this early dispersal. Shen et al. (2002) have dated Liujang Man to 111,000 to 139,000 years before the present. Liu et al. (2015) claim that modern human teeth have been found in China dating to at least 80 000 years ago.
Southern Route dispersal
By some 70,000 years ago, a part of the bearers of mitochondrial haplogroup L3 migrated from East Africa into the Near East. It has been estimated that from a population of 2,000 to 5,000 individuals in Africa, only a small group, possibly as few as 150 to 1,000 people, crossed the Red Sea.
The group that crossed the Red Sea travelled along the coastal route around the coast of Arabia and Persia until reaching India, which appears to be the first major settling point. Geneticist Spencer Wells says that the early travellers followed the southern coastline of Asia, crossed about 250 kilometres (155 mi) of sea, and colonized Australia by around 50,000 years ago. The Aborigines of Australia, Wells says, are the descendants of the first wave of migrations.
Today at the Bab-el-Mandeb straits, the Red Sea is about 20 kilometres (12 mi) wide, but 50,000 years ago sea levels were 70 m (230 ft) lower (owing to glaciation) and the water was much narrower. Though the straits were never completely closed, they were narrow enough and there may have been islands in between to have enabled crossing using simple rafts. Shell middens 125,000 years old have been found in Eritrea, indicating the diet of early humans included seafood obtained by beachcombing.
Dating: pre-or post-Toba
The dating of the Southern Dispersal is a matter of dispute. It may have happened either pre- or post-Toba, a catastrophic volcanic eruption that took place between 69,000 and 77,000 years ago at the site of present-day Lake Toba. Stone tools discovered below the layers of ash disposed in India may point to a pre-Toba dispersal, but the exact source of these tools is disputed.
An indication for post-Toba is haplo-group L3, that originated before the dispersal of humans out of Africa, and can be dated to 60,000–70,000 years ago, "suggesting that humanity left Africa a few thousand years after Toba." Yet, new research showing slower than previously thought genetic mutations in human DNA published in 2012, indicating a revised dating for the migration of between 90,000 and 130,000 years ago.
Peopling of Europe
According to Martin Meredith, members of one branch of Homo sapiens left Africa at some point between 125,000 and 60,000 years ago, and over time these humans replaced other populations of the genus Homo such as Neanderthals and Homo erectus.
According to Macaulay et al. (2005) an early offshoot from the southern disposal with haplogroup N followed the Nile from East Africa, heading northwards and crossing into Asia through the Sinai. This group then branched in several directions, some moving into Europe and others heading east into Asia. This hypothesis is supported by the relatively late date of the arrival of modern humans in Europe as well as by both archaeological and DNA evidence.
Based on an analysis of 55 complete human mitochondrial genomes (mtDNAs) of hunter-gatherers, Posth et al. (2016) argue for a "rapid single dispersal of all non-Africans less than 55,000 years ago."
Several authors have argued for multiple dispersals. Spencer Wells, in The Journey of Man (2002) describes two waves of migration, first the southern coastal route, then a northern migration into Europe at circa 45,000 years ago.[note 1] This possibility is ruled out by Macauly et al. (2005) and Posth et al. (2016), arguing for a single coastal dispersal.
Eve and Adam
Two pieces of the human genome are quite useful in deciphering human history: mitochondrial DNA and the Y chromosome. These are the only two parts of the genome that are not shuffled about by the evolutionary mechanisms that generate diversity with each generation: instead, these elements are passed down intact. According to the hypothesis, all people alive today have inherited the same mitochondria from a woman who lived in Africa about 160,000 years ago. She has been named Mitochondrial Eve. All men living today have inherited their Y chromosomes from a man who lived 140,000–500,000 years ago, probably in Africa. He has been named Y-chromosomal Adam. Based on comparisons of non-sex-specific chromosomes with sex-specific ones, it is now estimated that more men than women participated in the out-of-Africa exodus of early humans.
Haplogroup L and migrations within Africa
The first lineage to branch off from Mitochondrial Eve is L0. This haplogroup is found in high proportions among the San of Southern Africa, the Sandawe of East Africa. It is also found among the Mbuti people.
These groups branched off early in human history and have remained relatively genetically isolated since then. Haplogroups L1, L2 and L3 are descendents of L1-6 and are largely confined to Africa. The macro haplogroups M and N, which are the lineages of the rest of the world outside Africa, descend from L3. L3 is about 84,000 years old, and haplogroup M and N are almost identical in age at about 63,000 years old. The relationship between such gene trees and demographic history is still debated when applied to dispersals.
L3 and single dispersal
Some researchers think that only a few people left Africa in a single migration that went on to populate the rest of the world, based on the fact that only descendents of L3 are found outside Africa.
Of all the lineages present in Africa only the female descendants of one lineage, mtDNA haplogroup L3, are found outside Africa. If there had been several migrations, one would expect descendants of more than one lineage to be found outside Africa. L3's female descendants, the M and N haplogroup lineages, are found in very low frequencies in Africa (although haplogroup M1 populations are very ancient and diversified in North and Northeast Africa) and appear to be more recent arrivals. A possible explanation is that these mutations occurred in East Africa shortly before the exodus and became the dominant haplogroups after the exodus from Africa through the founder effect. Alternatively, the mutations may have arisen shortly after the exodus from Africa.
Africans, Eurasians and East Asians
Although mitochondrial DNA and Y-chromosomal DNA are particularly useful in deciphering human history, data on the genomes of dozens of population groups have also been studied.
In June 2009, an analysis of genome-wide SNP data from the International HapMap Project (Phase II) and CEPH Human Genome Diversity Panel samples was published. Those samples were taken from 1138 unrelated individuals.
Before this analysis, population geneticists expected to find dramatic differences among ethnic groups, with derived alleles shared among such groups but uncommon or nonexistent in other groups. Instead the study of 53 populations taken from the HapMap and CEPH data revealed that the population groups studied fell into just three genetic groups: Africans, Eurasians (which includes natives of Europe and the Middle East, and Southwest Asians east to present-day Pakistan), and East Asians, which includes natives of Asia, Japan, Southeast Asia, the Americas, and Oceania.
The study determined that most ethnic group differences can be attributed to genetic drift, with modern African populations having greater genetic diversity than the other two genetic groups, and modern Eurasians somewhat more than modern East Asians. The study suggested that natural selection may shape the human genome much more slowly than previously thought, with factors such as migration within and among continents more heavily influencing the distribution of genetic variations.
A May 2002 study examined three groups, African, European, and Asian. It found greater genetic diversity among Africans than among Eurasians, and that genetic diversity among Eurasians is largely a subset of that among Africans, supporting the 'out of Africa' model.
Southern Route and haplogroups M and N
Results from mtDNA collected from aboriginal Malaysians called Orang Asli and the creation of a phylogentic tree indicate that the hapologroups M and N share characteristics with original African groups from approximately 85,000 years ago and share characteristics with sub-haplogroups among coastal southeast Asian regions, such as Australasia, the Indian Subcontinent, and throughout continental Asia, which had dispersed and separated from its African origins approximately 65,000 years ago. This southern coastal dispersion would have occurred before the dispersion through the Levant approximately 45,000 years ago. This hypothesis attempts to explain why haplogroup N is predominant in Europe and why haplogroup M is absent in Europe. Evidence of the coastal migration is hypothesized to have been destroyed by the rise in sea levels during the Holocene epoch. Alternatively, a small European founder population that initially expressed both haplogroup M and N could have lost haplogroup M through random genetic drift resulting from a bottleneck (i.e. a founder effect).
The group that crossed the Red Sea travelled along the coastal route around the coast of Arabia and Persia until reaching India, which appears to be the first major settling point. Haplogroup M is found in high frequencies along the southern coastal regions of Pakistan and India and it has the greatest diversity in India, indicating that it is here where the mutation may have occurred. Sixty percent of the Indian population belong to Haplogroup M.
The indigenous people of the Andaman Islands also belong to the M lineage. The Andamanese are thought to be offshoots of some of the earliest inhabitants in Asia because of their long isolation from mainland Asia. They are evidence of the coastal route of early settlers that extends from India along the coasts of Thailand and Indonesia all the way to Papua New Guinea. Since M is found in high frequencies in highlanders from New Guinea as well, and both the Andamanese and New Guineans have dark skin and Afro-textured hair, some scientists think they are all part of the same wave of migrants who departed across the Red Sea ~60,000 years ago in the Great Coastal Migration.
Notably, the findings of Harding et al. show that, at least with regard to dark skin color, the haplotype background of Papua New Guineans at MC1R (one of a number of genes involved in melanin production) is identical to that of Africans (barring a single silent mutation). Thus, although these groups are distinct from Africans at other loci (due to drift, bottlenecks, etc.), it is evident that selection for the dark skin color trait likely continued (at least at MC1R) following the exodus. This would support the hypothesis that suggests that the original migrants from Africa resembled pre-exodus Africans (at least in skin color), and that the present day remnants of this ancient phenotype can be seen among contemporary Africans, Andamanese and New Guineans. Others suggest that their physical resemblance to Africans could be the result of convergent evolution.
From Arabia to India the proportion of haplogroup M increases eastwards: in eastern India, M outnumbers N by a ratio of 3:1. However, crossing over into East Asia, Haplogroup N reappears as the dominant lineage. M is predominant in South East Asia but amongst Indigenous Australians N reemerges as the more common lineage. This discontinuous distribution of Haplogroup N from Europe to Australia can be explained by founder effects and population bottlenecks. In addition to genetic analysis, Petraglia et al. also examines the microlithic materials from Indian subcontinent and explains the expansion of population based on the reconstruction of paleoenvironment. He proposed that microlithic industries could be traced back to 35ka in South Asia, and the new technology might be influenced by environmental change and population pressure.
Admixture of archaic and modern humans
Genetic testing in the last decade has revealed that several now extinct archaic human species may have interbred with modern humans. These species have been claimed to have left their genetic imprint in different regions across the world: Neanderthals in all humans except Sub-Saharan Africans, Denisova hominin in Australasia (for example, Melanesians, Aboriginal Australians and some Negritos) and there could also have been interbreeding between Sub-Saharan Africans and an as-yet-unknown hominin (possibly remnants of the ancient species Homo heidelbergensis). However, the rate of interbreeding was found to be relatively low (1–10%) and other studies have suggested that the presence of Neanderthal or other archaic human genetic markers in modern humans can be attributed to shared ancestral traits originating from a common ancestor 500,000 to 800,000 years ago. Still, a study published in March 2016 provided fresh evidence of interbreeding between modern humans and hominins, including Denisovans and Neanderthals, indicating that such interbreeding occurred at multiple times during human history.
History of the theory
With the development of anthropology in the early 19th century, scholars disagreed vigorously about different theories of human development. Those such as Johann Friedrich Blumenbach and James Cowles Prichard held that since the creation, the various human races had developed as different varieties sharing descent from one people (monogenism). Their opponents, such as Louis Agassiz and Josiah C. Nott, argued for polygenism, or the separate development of human races as separate species or had developed as separate species through transmutation of species from apes, with no common ancestor.
Charles Darwin was one of the first to propose common descent of living organisms, and among the first to suggest that all humans had in common ancestors who lived in Africa. Darwin first suggested the "Out of Africa" hypothesis after studying the behaviour of African apes, one of which was displayed at the London Zoo. The anatomist Thomas Huxley had also supported the hypothesis and suggested that African apes have a close evolutionary relationship with humans. These views were however opposed by the German biologist Ernst Haeckel, who was a proponent of the Out of Asia theory. Haeckel argued that humans were more closely related to the primates of Southeast Asia and rejected Darwin’s hypothesis of Africa.
In the Descent of Man, Darwin speculated that humans had descended from apes which still had small brains but walked upright, freeing their hands for uses which favoured intelligence. Further, he thought such apes were African:
In each great region of the world the living mammals are closely related to the extinct species of the same region. It is, therefore, probable that Africa was formerly inhabited by extinct apes closely allied to the gorilla and chimpanzee; and as these two species are now man's nearest allies, it is somewhat more probable that our early progenitors lived on the African continent than elsewhere. But it is useless to speculate on this subject, for an ape nearly as large as a man, namely the Dryopithecus of Lartet, which was closely allied to the anthropomorphous Hylobates, existed in Europe during the Upper Miocene period; and since so remote a period the earth has certainly undergone many great revolutions, and there has been ample time for migration on the largest scale.— Charles Darwin, Descent of Man
The prediction was insightful, because in 1871 there were hardly any human fossils of ancient hominids available. Almost fifty years later, Darwin's speculation was supported when anthropologists began finding numerous fossils of ancient small-brained hominids in several areas of Africa (list of hominina fossils).
Monogenism and Mitochondrial Eve
The debate in anthropology had swung in favour of monogenism by the mid-20th century. Isolated proponents of polygenism held forth in the mid-20th century, such as Carleton Coon, who hypothesized as late as 1962 that Homo sapiens arose five times from Homo erectus in five places. The "Recent African origin" of modern humans means "single origin" (monogenism) and has been used in various contexts as an antonym to polygenism.
In the 1980s Allan Wilson together with Rebecca L. Cann and Mark Stoneking worked on the so-called "Mitochondrial Eve" hypothesis. In his efforts to identify informative genetic markers for tracking human evolutionary history, he started to focus on mitochondrial DNA (mtDNA) – genes that sit in the cell, but not in the nucleus, and are passed from mother to child. This DNA material is important because it mutates quickly, thus making it easy to plot changes over relatively short time spans. By comparing differences in the mtDNA Wilson thought it was possible to estimate the time, and the place, modern humans first evolved. With his discovery that human mtDNA is genetically much less diverse than chimpanzee mtDNA, he concluded that modern human populations had diverged recently from a single population while older human species such as Neandertals and Homo erectus had become extinct. He and his team compared mtDNA in people of different ancestral backgrounds and concluded that all modern humans evolved from one 'lucky mother' in Africa about 150,000 years ago. With the advent of archaeogenetics in the 1990s, scientists were able to date the "out of Africa" migration with some confidence.
In 2000, the mitochondrial DNA (mtDNA) sequence of "Mungo Man 3" (LM3) of ancient Australia was published. This work was later questioned and explained by W. James Peacock, leader of the team who sequenced Mungo man's aDNA. In addition, a large-scale genotyping analysis of aboriginal Australians, New Guineans, Southeast Asians and Indians in 2013 showed close genetic relationship between Australian, New Guinean, and the Mamanwa people, with divergence times for these groups estimated at 36,000 y ago. Further, substantial gene flow was detected between the Indian populations and aboriginal Australians, indicating an early "southern route" migration out of Africa, and arrival of other populations in the region by subsequent dispersal. This basically opposes the view that there was an isolated human evolution in Australia.
According to Smith et al. (2003), the results indicated that Mungo Man was an extinct subspecies that diverged before the most recent common ancestor of contemporary humans, and supports the multiregional origin of modern humans hypothesis.
The multiregional hypothesis, initially proposed by Milford Wolpoff, holds that the evolution of humans from H. erectus at the beginning of the Pleistocene 1.8 million years BP has been within a single, continuous worldwide population. Proponents of multiregional origin reject the assumption of an infertility barrier between ancient Eurasian and African populations of Homo. Multiregional proponents point to the fossil record and genetic evidence in chromosomal DNA. One study suggested that at least 5% of the human modern gene pool can be attributed to ancient admixture, which in Europe would be from the Neanderthals. But the study also suggests that there may be other reasons why humans and Neanderthals share ancient genetic lineages.
- Archaeogenetics of the Near East
- Behavioral modernity
- Coastal migration
- Dawn of Humanity (2015 PBS film)
- Early human migrations
- Genetics and archaeogenetics of South Asia
- Genetic history of Europe
- Genetic history of indigenous peoples of the Americas
- Genetic history of Italy
- Genetic history of North Africa
- Genetic history of the British Isles
- Genetic history of the Iberian Peninsula
- Hofmeyr Skull
- Human timeline
- Identical ancestors point
- Indo-Aryan migration theory
- Sahara pump theory
- The Incredible Human Journey
- Timeline of human evolution
- Kay Young McChesney: "Wells (2003) divided the descendants of men who left Africa into a genealogical tree with 11 lineages. Each genetic marker represents a single-point mutation (SNP) at a specific place in the genome. First, genetic evidence suggests that a small band with the marker M168 migrated out of Africa along the coasts of the Arabian Peninsula and India, through Indonesia, and reached Australia very early, between 60,000 and 50,000 years ago. This very early migration into Australia is also supported by Rasmussen et al. (2011). Second, a group bearing the marker M89 moved out of northeastern Africa into the Middle East 45,000 years ago. From there, the M89 group split into two groups. One group that developed the marker M9 went into Asia about 40,000 years ago. The Asian (M9) group split three ways: into Central Asia (M45), 35,000 years ago; into India (M20), 30,000 years ago; and into China (M122), 10,000 years ago. The Central Asian (M45) group split into two groups: toward Europe (M173), 30,000 years ago and toward Siberia (M242), 20,000 years ago. Finally, the Siberian group (M242) went on to populate North and South America (M3), about 10,000 years ago.
- Liu H, Prugnolle F, Manica A, Balloux F; Prugnolle; Manica; Balloux (August 2006). "A geographically explicit genetic model of worldwide human-settlement history". Am. J. Hum. Genet. 79 (2): 230–7. doi:10.1086/505436. PMC . PMID 16826514.
Currently available genetic and archaeological evidence is supportive of a recent single origin of modern humans in East Africa. However, this is where the consensus on human settlement history ends, and considerable uncertainty clouds any more detailed aspect of human colonization history.
- "This week in Science: Out of Africa Revisited". Science. 308 (5724): 921. 13 May 2005. doi:10.1126/science.308.5724.921g.
- Stringer C (June 2003). "Human evolution: Out of Ethiopia". Nature. 423 (6941): 692–3, 695. Bibcode:2003Natur.423..692S. doi:10.1038/423692a. PMID 12802315.
- Johanson D. "Origins of Modern Humans: Multiregional or Out of Africa?". ActionBioscience. American Institute of Biological Sciences.
- "Modern Humans – Single Origin (Out of Africa) vs Multiregional".
- Meredith 2011.
- "Both Australian Aborigines and Europeans Rooted in Africa". News.softpedia.com. Retrieved 11 January 2011.
- Posth 2016.
- Out of Africa Hypothesis
- Armitage SJ, Jasim SA, Marks AE, Parker AG, Usik VI, Uerpmann HP; Jasim; Marks; Parker; Usik; Uerpmann (January 2011). "The southern route "out of Africa": evidence for an early expansion of modern humans into Arabia". Science. 331 (6016): 453–6. Bibcode:2011Sci...331..453A. doi:10.1126/science.1199113. PMID 21273486.
- Balter M (January 2011). "Was North Africa the launch pad for modern human migrations?" (PDF). Science. 331 (6013): 20–3. Bibcode:2011Sci...331...20B. doi:10.1126/science.331.6013.20. PMID 21212332.
- Cruciani F, Trombetta B, Massaia A, Destro-Bisol G, Sellitto D, Scozzari R; Trombetta; Massaia; Destro-Bisol; Sellitto; Scozzari (June 2011). "A revised root for the human Y chromosomal phylogenetic tree: the origin of patrilineal diversity in Africa". Am. J. Hum. Genet. 88 (6): 814–8. doi:10.1016/j.ajhg.2011.05.002. PMC . PMID 21601174.
- Smith TM, Tafforeau P, Reid DJ, Grün R, Eggins S, Boutakiout M, Hublin JJ; Tafforeau; Reid; Grün; Eggins; Boutakiout; Hublin (April 2007). "Earliest evidence of modern human life history in North African early Homo sapiens". Proc. Natl. Acad. Sci. U.S.A. 104 (15): 6128–33. Bibcode:2007PNAS..104.6128S. doi:10.1073/pnas.0700747104. PMC . PMID 17372199.
- Liu 2015.
- K. Kris Hirst, Southern Dispersal Route – Early Modern Humans Leave Africa
- Macaulay 2005.
- Robert Jurmain; Lynn Kilgore; Wenda Trevathan (20 March 2008). Essentials of Physical Anthropology. Cengage Learning. pp. 266–. ISBN 978-0-495-50939-4. Retrieved 14 June 2011.
- Wolpoff MH, Hawks J, Caspari R; Hawks; Caspari (May 2000). "Multiregional, not multiple origins". Am. J. Phys. Anthropol. 112 (1): 129–36. doi:10.1002/(SICI)1096-8644(200005)112:1<129::AID-AJPA11>3.0.CO;2-K. PMID 10766948.
- Eric Delson; Ian Tattersall; John A. Van Couvering (2000). Encyclopedia of human evolution and prehistory. Taylor & Francis. p. 677–. ISBN 978-0-8153-1696-1. Retrieved 14 June 2011.
- White TD, Asfaw B, DeGusta D, Gilbert H, Richards GD, Suwa G, Howell FC; Asfaw; Degusta; Gilbert; Richards; Suwa; Howell (June 2003). "Pleistocene Homo sapiens from Middle Awash, Ethiopia". Nature. 423 (6941): 742–7. Bibcode:2003Natur.423..742W. doi:10.1038/nature01669. PMID 12802332.
- "160,000-year-old fossilized skulls uncovered in Ethiopia are oldest anatomically modern humans". University of California, Berkeley. 2003.
- "Ancestral tools". Handprint.com. 1 August 1999. Retrieved 11 January 2011.
- "Middle to upper paleolithic transition". Wsu.edu. Retrieved 11 January 2011.
- Liu H, Prugnolle F, Manica A, Balloux F; Prugnolle; Manica; Balloux (August 2006). "A geographically explicit genetic model of worldwide human-settlement history". Am. J. Hum. Genet. 79 (2): 230–7. doi:10.1086/505436. PMC . PMID 16826514.
- Hershkovitz 2015.
- "55,000-Year-Old Skull Fossil Sheds New Light on Human Migration out of Africa". Science News. Retrieved 2 February 2015.
- Groucutt 2015.
- Bowler JM, Johnston H, Olley JM, Prescott JR, Roberts RG, Shawcross W, Spooner NA.; Johnston; Olley; Prescott; Roberts; Shawcross; Spooner (2003). "New ages for human occupation and climatic change at Lake Mungo, Australia". Nature. 421 (6925): 837–40. Bibcode:2003Natur.421..837B. doi:10.1038/nature01383. PMID 12594511.
- Olleya JM, Roberts RG, Yoshida H, Bowler JM (2006). "Single-grain optical dating of grave-infill associated with human burials at Lake Mungo, Australia". Quaternary Science Reviews. 25 (19–20): 2469–2474. Bibcode:2006QSRv...25.2469O. doi:10.1016/j.quascirev.2005.07.022.
- Hu Y, Shang H, Tong H, Nehlich O, Liu W, Zhao C, Yu J, Wang C, Trinkaus E, Richards MP; Shang; Tong; Nehlich; Liu; Zhao; Yu; Wang; Trinkaus; Richards (July 2009). "Stable isotope dietary analysis of the Tianyuan 1 early modern human". Proc. Natl. Acad. Sci. U.S.A. 106 (27): 10971–4. Bibcode:2009PNAS..10610971H. doi:10.1073/pnas.0904826106. PMC . PMID 19581579.
- Brown P (August 1992). "Recent human evolution in East Asia and Australasia". Philos. Trans. R. Soc. Lond., B, Biol. Sci. 337 (1280): 235–42. doi:10.1098/rstb.1992.0101. PMID 1357698.
- Literature: Göran Burenhult: Die ersten Menschen, Weltbild Verlag, 2000. ISBN 3-8289-0741-5
- Beyin 2011.
- Appenzeller 2015.
- The Bradshaw Foundation and Stephen Oppenheimer, Journey of Mankind. The peopling of the world.
- "Humans may have left Africa earlier than thought". Apnews.myway.com. Retrieved 14 June 2011.
- Scerri, Eleanor M. L.; Drake, Nick A.; Jennings, Richard; Groucutt, Huw S. (1 October 2014). "Earliest evidence for the structure of Homo sapiens populations in Africa". Quaternary Science Reviews. 101: 207–216. doi:10.1016/j.quascirev.2014.07.019.
- Finlayson 2009, p. 68.
- Kuhlwilm 2016.
- Dienekes'Anthropology Blog, Ancestors of Eastern Neandertals admixed with modern humans 100 thousand years ago
- Shen 2002.
- Dieneks' Anthropology Blog, Modern humans in China ~80,000 years ago (?)
- Zhivotovsky; Rosenberg, NA; Feldman, MW; et al. (2003). "Features of Evolution and Expansion of Modern Humans, Inferred from Genomewide Microsatellite Markers". American Journal of Human Genetics. 72 (5): 1171–86. doi:10.1086/375120. PMC . PMID 12690579.
- Stix, Gary (2008). "The Migration History of Humans: DNA Study Traces Human Origins Across the Continents". Retrieved 14 June 2011.
- Metspalu M, Kivisild T, Metspalu E, Parik J, Hudjashov G, Kaldma K, Serk P, Karmin M, Behar DM, Gilbert MT, Endicott P, Mastana S, Papiha SS, Skorecki K, Torroni A, Villems R (August 2004). "Most of the extant mtDNA boundaries in south and southwest Asia were likely shaped during the initial settlement of Eurasia by anatomically modern humans". BMC Genet. 5: 26. doi:10.1186/1471-2156-5-26. PMC . PMID 15339343.
- Rincon, Paul (24 April 2008). "Human line 'nearly split in two'". BBC News. Retrieved 31 December 2009.
- Fernandes et. al (June 2006). "Absence of post-Miocene Red Sea land bridges: biogeographic implications". Journal of Biogeography. 33 (6): 961–966. doi:10.1111/j.1365-2699.2006.01478.x.
- Beyin, Amanuel (February 2011). "Upper Pleistocene Human Dispersals out of Africa: A Review of the Current State of the Debate". International Journal of Evolutionary Biology. 2011 (615094): 1–17. doi:10.4061/2011/615094.
- Walter RC, Buffler RT, Bruggemann JH, Guillaume MM, Berhe SM, Negassi B, Libsekal Y, Cheng H, Edwards RL, von Cosel R, Néraudeau D, Gagnon M (May 2000). "Early human occupation of the Red Sea coast of Eritrea during the last interglacial". Nature. 405 (6782): 65–9. doi:10.1038/35011048. PMID 10811218.
- Catherine Brahic (24 November 2012). "Our True Dawn". New Scientist. Reed Business Information (2892): 34–7. ISSN 0262-4079.
- Dienekes' Anthroplogy Bog, mtDNA from 55 hunter-gatherers across 35,000 years in Europe
- Posth 2016, p. 1.
- Wells 2002.
- Bradshaw Foundation, Human Migration
- Young McChesney 2015.
- Macauly 2005.
- Jones, Marie; John Savino (2007). Supervolcano: The Catastrophic Event That Changed the Course of Human History (Could Yellowstone be Next?). Franklin Lakes, NJ: New Page Books. ISBN 1-56414-953-6.
- Cann RL, Stoneking M, Wilson AC; Stoneking; Wilson (1987). "Mitochondrial DNA and human evolution". Nature. 325 (6099): 31–6. Bibcode:1987Natur.325...31C. doi:10.1038/325031a0. PMID 3025745.
- Vigilant L, Stoneking M, Harpending H, Hawkes K, Wilson AC; Stoneking; Harpending; Hawkes; Wilson (September 1991). "African populations and the evolution of human mitochondrial DNA". Science. 253 (5027): 1503–7. Bibcode:1991Sci...253.1503V. doi:10.1126/science.1840702. PMID 1840702.
- Keinan A, Mullikin JC, Patterson N, Reich D; Mullikin; Patterson; Reich (January 2009). "Accelerated genetic drift on chromosome X during the human dispersal out of Africa". Nat. Genet. 41 (1): 66–70. doi:10.1038/ng.303. PMC . PMID 19098910.
- Gonder MK, Mortensen HM, Reed FA, de Sousa A, Tishkoff SA; Mortensen; Reed; De Sousa; Tishkoff (March 2007). "Whole-mtDNA genome sequence analysis of ancient African lineages". Mol. Biol. Evol. 24 (3): 757–68. doi:10.1093/molbev/msl209. PMID 17194802.
- Chen YS, Olckers A, Schurr TG, Kogelnik AM, Huoponen K, Wallace DC; Olckers; Schurr; Kogelnik; Huoponen; Wallace (April 2000). "mtDNA variation in the South African Kung and Khwe-and their genetic relationships to other African populations". Am. J. Hum. Genet. 66 (4): 1362–83. doi:10.1086/302848. PMC . PMID 10739760.
- Macaulay, V; Hill, C; Achilli, A; Rengo, C; Clarke, D; Meehan, W; Blackburn, J; Semino, O; Scozzari, R; et al. (2005). "Single, Rapid Coastal Settlement of Asia Revealed by Analysis of Complete Mitochondrial Genomes". Science. 308 (5724): 1034–6. doi:10.1126/science.1109792. PMID 15890885.
- Coop G, Pickrell, Novembre, Kudaravalli, Li, Absher, Myers, Cavalli-Sforza, Feldman, Pritchard (June 2009). Schierup MH, ed. "The role of geography in human adaptation". PLoS Genet. 5 (6): e1000500. doi:10.1371/journal.pgen.1000500. PMC . PMID 19503611.
- Brown, David (22 June 2009). "Among Many Peoples, Little Genomic Variety". The Washington Post. Retrieved 25 June 2009.
- "Geography And History Shape Genetic Differences In Humans". Science Daily. 7 June 2009. Retrieved 25 June 2009.
- Yu, Ning; et al. (May 2002). "Larger Genetic Differences Within Africans Than Between Africans and Eurasians". Genetics. Genetics Society of America. Retrieved 7 April 2013.
- Searching for traces of the Southern Dispersal, by Dr. Marta Mirazón Lahr, et al.
- "A single origin, several dispersal hypothesis". Biomedcentral.com. 29 October 2004. Retrieved 11 January 2011.
- Harding, et al. 2000, p. 1355
- "Evolution of Human Languages". Ehl.santafe.edu. Retrieved 2011-01-11.
- Endicott P, Gilbert MT, Stringer C, Lalueza-Fox C, Willerslev E, Hansen AJ, Cooper A (January 2003). "The genetic origins of the Andaman Islanders". Am. J. Hum. Genet. 72 (1): 178–84. doi:10.1086/345487. PMC . PMID 12478481.
- Ingman M, Gyllensten U (July 2003). "Mitochondrial genome variation and evolutionary history of Australian and New Guinean aborigines". Genome Res. 13 (7): 1600–6. doi:10.1101/gr.686603. PMC . PMID 12840039.
- Petraglia, M.; Clarkson, C.; Boivin, N.; Haslam, M.; Korisettar, R.; Chaubey, G.; Arnold, L. (2009). "Population increase and environmental deterioration correspond with microlithic innovations in South Asia ca. 35,000 years ago". Proceedings of the National Academy of Sciences. 106 (30): 12261–12266. doi:10.1073/pnas.0810842106.
- The Human Stew
- . doi:10.1371/journal.pgen.1002837. Missing or empty
- Zimmer, Carl (17 March 2016). "Humans Interbred With Hominins on Multiple Occasions, Study Finds". The New York Times. Retrieved 17 March 2016.
- Peter Lafreniere (22 September 2010). Adaptive Origins: Evolution and Human Development. Taylor & Francis. p. 90. ISBN 978-0-8058-6012-2. Retrieved 14 June 2011.
- Robinson D, Ash PM (2010). The Emergence of Humans: An Exploration of the Evolutionary Timeline. New York: Wiley. ISBN 0-470-01315-X.
- Palmer D (2006). Prehistoric Past Revealed: The Four Billion Year History of Life on Earth. Berkeley: University of California Press. p. 43. ISBN 0-520-24827-9.
- Regal B (2004). Human evolution: a guide to the debates. Santa Barbara, Calif: ABC-CLIO. pp. 73–75. ISBN 1-85109-418-0.
- Bowler 2003, p. 213
- "The descent of man Chapter 6 – On the Affinities and Genealogy of Man". Darwin-online.org.uk. Retrieved 11 January 2011.
- Jackson JP Jr (2001). ""In Ways Unacademical": The Reception of Carleton S. Coon's The Origin of Races" (pdf). Journal of the History of Biology. 34 (2): 247–285. doi:10.1023/A:1010366015968.
- "Allan Wilson: Revolutionary Evolutionist". New Zealanders Heroes.
- Adcock GJ, Dennis ES, Easteal S, Huttley GA, Jermiin LS, Peacock WJ, Thorne A; Dennis; Easteal; Huttley; Jermiin; Peacock; Thorne (January 2001). "Mitochondrial DNA sequences in ancient Australians: Implications for modern human origins". Proc. Natl. Acad. Sci. U.S.A. 98 (2): 537–42. Bibcode:2001PNAS...98..537A. doi:10.1073/pnas.98.2.537. PMC . PMID 11209053.
- Australia Challenges Out-of-Africa Theory ABC News 9 January 2003
- Cooper A, Rambaut A, Macaulay V, Willerslev E, Hansen AJ, Stringer C; Rambaut; MacAulay; Willerslev; Hansen; Stringer (June 2001). "Human origins and ancient human DNA". Science. 292 (5522): 1655–6. doi:10.1126/science.292.5522.1655. PMID 11388352.
- Schiller J (2010). Human Evolution: Neanderthals & Homo sapiens. CreateSpace. p. 66. ISBN 978-1-4515-4608-8. Retrieved 29 November 2011.
- Pugach I, Delfin F, Gunnarsdóttir E, Kayser M, Stoneking M; Delfin; Gunnarsdóttir; Kayser; Stoneking (2013). "Genome-wide data substantiate Holocene gene flow from India to Australia". Proc Natl Acad Sci U S A. 110 (5): 1803–1808. Bibcode:2013PNAS..110.1803P. doi:10.1073/pnas.1211927110. PMC . PMID 23319617.
- Smith CI, Chamberlain AT, Riley MS, Stringer C, Collins MJ; Chamberlain; Riley; Stringer; Collins (September 2003). "The thermal history of human fossils and the likelihood of successful DNA amplification" (PDF). J. Hum. Evol. 45 (3): 203–17. doi:10.1016/S0047-2484(03)00106-4. PMID 14580590.
- Plagnol V, Wall JD (July 2006). "Possible ancestral structure in human populations". PLoS Genet. 2 (7): e105. doi:10.1371/journal.pgen.0020105. PMC . PMID 16895447.
..strong evidence for ancient admixture in both a European and a West African population (p ≈ 10−7), with contributions to the modern gene pool of at least 5%. While Neanderthals form an obvious archaic source population candidate in Europe..
- Green RE, Krause J, Briggs AW, et al. (May 2010). "A draft sequence of the Neandertal genome". Science. 328 (5979): 710–22. Bibcode:2010Sci...328..710G. doi:10.1126/science.1188021. PMID 20448178. Lay summary – BBC News.
- Blum MG, Jakobsson M (October 2010). "Deep divergences of human gene trees and models of human origins". Mol. Biol. Evol. 28 (2): 889–98. doi:10.1093/molbev/msq265. PMID 20930054.
- Appenzeller, Tim (2012). "Human migrations: Eastern odyssey. Humans had spread across Asia by 50,000 years ago. Everything else about our original exodus from Africa is up for debate.". Nature. 485 (7396).
- Beyin, Amanuel (2011). "Upper Pleistocene Human Dispersals out of Africa: A Review of the Current State of the Debate". International Journal of Evolutionary Biology. 2011: 615094.
- Finlayson, Clive (2011). The humans who went extinct: why Neanderthals died out and we survived. Oxford University Press US. ISBN 978-0-19-923918-4.
- Groucutt, Huw S.; et al. (2015). "Rethinking the dispersal of Homo sapiens out of Africa". Evolutionary Anthropology. Wiley. pp. 149–164, July/August 2015.
- Hershkovitz, Israel; Marder, Ofer; Ayalon, Avner; Bar-Matthews, Miryam; Yasur, Gal; Boaretto, Elisabetta; Caracuta, Valentina; Alex, Bridget; et al. (2015). "Levantine cranium from Manot Cave (Israel) foreshadows the first European modern humans". Nature. Epub ahead of print. doi:10.1038/nature14134. PMID 25629628.
- Kuhlwilm, Martin; et al. (2016), "Ancient gene flow from early modern humans into Eastern Neanderthals", Nature, 530: 429–433, doi:10.1038/nature16544
- Liu, Wu; Martinón-Torres, María; Cai, Yan-jun; Xing, Song; Tong, Hao-wen; Pei, Shu-wen; Sier, Mark Jan; Wu, Xiao-hong; Edwards, R. Lawrence (2015). "The earliest unequivocally modern humans in southern China". Nature. doi:10.1038/nature15696.
- Macaulay, Vincent; Hill, Catherine; Achilli, Alessandro; Rengo, Chiara; Clarke, Douglas; Meehan, William; Blackburn, James; Semino, Ornella; Scozzari, Rosaria; Cruciani, Fulvio; Taha, Adi; Shaari, Norazila Kassim; Raja, Joseph Maripa; Ismail, Patimah; Zainuddin, Zafarina; Goodwin, William; Bulbeck, David; Bandelt, Hans-Jürgen; Oppenheimer, Stephen; Torroni, Antonio; Richards, Martin (13 May 2005). "Single, Rapid Coastal Settlement of Asia Revealed by Analysis of Complete Mitochondrial Genomes". Science. 308 (5724): 1034–1036. doi:10.1126/science.1109792.
- Meredith, Martin (2011). Born in Africa: The Quest for the Origins of Human Life. New York: PublicAffairs. ISBN 1-58648-663-2.
- Posth, Cosimo (2016). "Pleistocene Mitochondrial Genomes Suggest a Single Major Dispersal of Non-Africans and a Late Glacial Population Turnover in Europe". Current Biology.
- Shen, G.; Wang; Wang; Zhao; Collerson; Zhou; Tobias (2002). "U-Series dating of Liujiang hominid site in Guangxi, Southern China". J. Hum. Evol. 43 (6): 817–29. doi:10.1006/jhev.2002.0601. PMID 12473485.
- Wells, Spencer, The Journey of Man: A Genetic Odyssey, Princeton University Press
- Young McChesney, Kai (2015), "Teaching Diversity. The Science You Need to Know to Explain Why Race Is Not Biological", SAGE open, doi:10.1177/2158244015611712
- Stringer, Chris (2011). The Origin of Our Species. London: Allen Lane. ISBN 978-1-84614-140-9.
- Wells, Spencer (2006). Deep ancestry: inside the Genographic Project. Washington, D.C: National Geographic. ISBN 0-7922-6215-8.
- Wade, N. (2006). Before the Dawn : Recovering the Lost History of Our Ancestors. Penguin Press HC, The. ISBN 1-59420-079-3.
- Sykes, Bryan (2004). The Seven Daughters of Eve: The Science That Reveals Our Genetic Ancestry. Corgi Adult. ISBN 0-552-15218-8.
- Spencer Wells (2002), The Journey of Man
- Macaulay, Vincent; et al. (13 May 2005). "Single, Rapid Coastal Settlement of Asia Revealed by Analysis of Complete Mitochondrial Genomes". Science. 308 (5724): 1034–1036. doi:10.1126/science.1109792. (Classic formulation of the single dispersal southern coastal route theory )
- Appenzeller, Tim (2012). "Human migrations: Eastern odyssey. Humans had spread across Asia by 50,000 years ago. Everything else about our original exodus from Africa is up for debate.". Nature. 485 (7396).
- Groucutt, Huw S.; et al. (2015). "Rethinking the dispersal of Homo sapiens out of Africa". Evolutionary Anthropology. Wiley. pp. 149–164, July/August 2015. (Overview of recent research, arguing for multiple dispersals)
- Liu, Wu; et al. (2015). "The earliest unequivocally modern humans in southern China". Nature. doi:10.1038/nature15696.
- Posth, Cosimo; et al. (2016). "Pleistocene Mitochondrial Genomes Suggest a Single Major Dispersal of Non-Africans and a Late Glacial Population Turnover in Europe". Current Biology. (Single dispersal, challenging Macaulay, offering new insights )
- Overview with multiple maps
- An mtDNA view of the peopling of the world by Homo sapiens (post-Toba)(archived version)
- Bradshaw Foundation: The Journey of Mankind (pre-Toba)
- Human evolution
- Encyclopædia Britannica, Human Evolution
- Human Timeline (Interactive) – Smithsonian, National Museum of Natural History (August 2016).
- Dienekes'Anthropology Blogspot (up-to-date reviews of recent genetic research)