The term Eurasian backflow, or Eurasian back-migrations, has been used to describe several pre-Neolithic and Neolithic migration events of humans from western Eurasia back to Africa. [1]
Homo sapiens had left Africa about 70-50,000 years ago, [3] [4] [5] and between 30,000-15,000 years ago migrated back from the Middle East into Northern Africa. About 3,000 years ago, [6] [7] or already earlier between 6,000-5,000 years ago, [8] farmers from Anatolia and the Near East migrated into the Horn of Africa. Signs of this migration can be found in the genomes of contemporary peoples from all over East Africa. [1] [9] Next to Eastern Africa, significant Eurasian ancestry is found in Northern Africa, and among specific ethnic groups of the Horn of Africa, as well as among the Malagasy people of Madagascar. Various genome studies found also evidence for multiple pre-historic back-migrations from various Eurasian populations and subsequent admixture with native groups. [10] West-Eurasian geneflow arrived to Northern Africa during the Paleolithic, followed by other Neolithic migration events. [6] Genetic data on the Taforalt samples "demonstrated that Northern Africa received significant amounts of gene-flow from Eurasia predating the Holocene and development of farming practices". [11] Medieval geneflow events, such as the Arab expansion also left traces in various African populations, but with Neolithization having a much larger demographic impact than Arabization. [12]
The people migrating back to Africa were closely related to the Neolithic farmers who had brought agriculture from the Near East to Europe about 7,000 years ago. This population is also closely related to present-day Sardinians, [1] although studies have made distinctions between the population that brought farming into Europe, and the Levantine related groups that spread southward into East Africa. [14] A study from 2020 inferred two sources for the spread of Eurasian admixture in Northeastern Africa, with one associated with pastoralism. The initial phase involved groups originating from the Levant and North Africa that gave rise to the Pastoral Neolithic. [15] Further research has shown that the back-migration into the region was a complex process, identifying multiple origins for the Eurasian component in Northeast African groups today. [16] [17]
A report in November 2015 on a 4,500-year-old Ethiopian genome [18] [19] had originally overestimated the genetic influence of the Eurasian backflow, claiming that signs of the migration could be found in genomes all over Africa. This mistaken claim was based on a data-processing error and was corrected in February 2016. The West Asian admixture was only predominant in the populations of the Horn of Africa, in particular Ethiopian highlanders, and less relevant or absent in the genetic makeup of West and Central Africans. [9]
In 2016, researchers recognized that the Neanderthal ancestry in African populations, strongly corresponds with the levels of Western Eurasian ancestry. The geneticists elaborated that: "Neanderthal ancestry is not expected in Africa, yet today many Africans carry Neanderthal-derived alleles. The plot shows that the Neanderthal ancestry proportion in Africans is correlated with gene flow from Eurasians. For example, knowing that today Eurasians carry ∼2% of Neanderthal ancestry, we observed that East Africans (Ethiopians) had ∼1% Neanderthal ancestry and ∼50% Eurasian ancestry. Correspondingly, Near Easterners showed a decline in Neanderthal ancestry proportional to their levels of African ancestry." [20]
Chen, Lu's publication found back-migrations contributed to the signal of Neanderthal ancestry in Africans. Data indicated that back-migrations giving Neanderthal sequences came after the split of Europeans and East Asians, from populations related to the European lineage. The overlap of this ancestral European ancestry and Neanderthal segments was highly significant. [21]
Early modern human (EMH), or anatomically modern human (AMH), are terms used to distinguish Homo sapiens that are anatomically consistent with the range of phenotypes seen in contemporary humans, from extinct archaic human species. This distinction is useful especially for times and regions where anatomically modern and archaic humans co-existed, for example, in Paleolithic Europe. Among the oldest known remains of Homo sapiens are those found at the Omo-Kibish I archaeological site in south-western Ethiopia, dating to about 233,000 to 196,000 years ago, the Florisbad site in South Africa, dating to about 259,000 years ago, and the Jebel Irhoud site in Morocco, dated about 315,000 years ago.
Genetics and archaeogenetics of South Asia is the study of the genetics and archaeogenetics of the ethnic groups of South Asia. It aims at uncovering these groups' genetic histories. The geographic position of the Indian subcontinent makes its biodiversity important for the study of the early dispersal of anatomically modern humans across Asia.
The genetic history of Europe includes information around the formation, ethnogenesis, and other DNA-specific information about populations indigenous, or living in Europe.
Early human migrations are the earliest migrations and expansions of archaic and modern humans across continents. They are believed to have begun approximately 2 million years ago with the early expansions out of Africa by Homo erectus. This initial migration was followed by other archaic humans including H. heidelbergensis, which lived around 500,000 years ago and was the likely ancestor of Denisovans and Neanderthals as well as modern humans. Early hominids had likely crossed land bridges that have now sunk.
The genetic history of the Middle East is the subject of research within the fields of human population genomics, archaeogenetics and Middle Eastern studies. Researchers use Y-DNA, mtDNA, and other autosomal DNAs to identify the genetic history of ancient and modern populations of Egypt, Persia, Mesopotamia, Anatolia, Arabia, the Levant, and other areas.
In paleoanthropology, the recent African origin of modern humans or the "Out of Africa" theory (OOA) is the most widely accepted model of the geographic origin and early migration of anatomically modern humans. It follows the early expansions of hominins out of Africa, accomplished by Homo erectus and then Homo neanderthalensis.
The Denisovans or Denisova hominins(di-NEE-sə-və) are an extinct species or subspecies of archaic human that ranged across Asia during the Lower and Middle Paleolithic, and lived, based on current evidence, from 285 to 25 thousand years ago. Denisovans are known from few physical remains; consequently, most of what is known about them comes from DNA evidence. No formal species name has been established pending more complete fossil material.
Interbreeding between archaic and modern humans occurred during the Middle Paleolithic and early Upper Paleolithic. The interbreeding happened in several independent events that included Neanderthals and Denisovans, as well as several unidentified hominins.
The genetic history of North Africa encompasses the genetic history of the people of North Africa. The most important source of gene flow to North Africa from the Neolithic Era onwards was from Western Asia, while the Sahara desert to the south and the Mediterranean Sea to the North were also important barriers to gene flow from sub-Saharan Africa and parts of Europe in prehistory. However, North Africa is connected to Western Asia via the Isthmus of Suez and the Sinai peninsula, while at the Straits of Gibraltar, North Africa and Europe are separated by only 15 km (9 mi), similarly Malta, Sicily, Canary Islands, Lampedusa and Crete are close to the coasts of North Africa.
The genetic history of Egypt reflects its geographical location at the crossroads of several major biocultural areas: North Africa, the Sahara, the Middle East, the Mediterranean and sub-Saharan Africa.
Genetic studies on Arabs refers to the analyses of the genetics of ethnic Arab people in the Middle East and North Africa and parts of Sub-Sahara Africa where Black Arabs claim descent. Arabs are genetically diverse as a result of their intermarriage and mixing with indigenous people of the pre-Islamic Middle East and North Africa following the Arab and Islamic expansion. Genetic ancestry components related to the Arabian Peninsula display an increasing frequency pattern from west to east over North Africa. A similar frequency pattern exist across northeastern Africa with decreasing genetic affinities to groups of the Arabian Peninsula along the Nile river valley across Sudan and the more they go south. This genetic cline of admixture is dated to the time of Arab expansion and immigration to North Africa (Maghreb) and northeast Africa.
A ghost population is a population that has been inferred through using statistical techniques.
In archaeogenetics, the term Ancient North Eurasian (ANE) is the name given to an ancestral component that represents the lineage of the people of the Mal'ta–Buret' culture and populations closely related to them, such as the Upper Paleolithic individuals from Afontova Gora in Siberia. Genetic studies also revealed that the ANE are closely related to the remains of the preceding Yana Culture, which were dubbed as 'Ancient North Siberians' (ANS). The Ancient North Eurasians represent a Paleolithic Siberian population having arrived via the "northern route" and being deeply related to Paleolithic and Mesolithic European hunter-gatherers, but also derive a significant amount of their ancestry from an East Eurasian source, having arrived to Siberia via the "southern route".
Early European Farmers (EEF) were a group of the Anatolian Neolithic Farmers (ANF) who brought agriculture to Europe and Northwest Africa. The Anatolian Neolithic Farmers were an ancestral component, first identified in farmers from Anatolia (also known as Asia Minor) in the Neolithic, and outside in Europe and Northwest Africa, they also existed in Iranian Plateau, South Caucasus, Mesopotamia and Levant. Although the spread of agriculture from the Middle East to Europe has long been recognised through archaeology, it is only recent advances in archaeogenetics that have confirmed that this spread was strongly correlated with a migration of these farmers, and was not just a cultural exchange.
In archaeogenetics, western hunter-gatherer is a distinct ancestral component of modern Europeans, representing descent from a population of Mesolithic hunter-gatherers who scattered over western, southern and central Europe, from the British Isles in the west to the Carpathians in the east, following the retreat of the ice sheet of the Last Glacial Maximum. It is closely associated and sometimes considered synonymous with the concept of the Villabruna cluster, named after Ripari Villabruna cave in Italy, known from the terminal Pleistocene of Europe, which is largely ancestral to later WHG populations.
Basal Eurasian is a proposed lineage of anatomically modern humans with reduced, or zero, archaic hominin (Neanderthal) admixture compared to other ancient non-Africans. Basal Eurasians represent a sister lineage to other Eurasians and may have originated from the Southern Middle East, specifically the Arabian peninsula, or North Africa, and are said to have contributed ancestry to various West Eurasian, South Asian, and Central Asian as well as African groups. This Basal Eurasian component is also proposed to explain the lower archaic admixture among modern West Eurasians compared to with East Eurasians, although alternatives without the need of such Basal admixture exist as well.
The genetic history of Africa summarizes the genetic makeup and population history of African populations in Africa, composed of the overall genetic history, including the regional genetic histories of North Africa, West Africa, East Africa, Central Africa, and Southern Africa, as well as the recent origin of modern humans in Africa. The Sahara served as a trans-regional passageway and place of dwelling for people in Africa during various humid phases and periods throughout the history of Africa.
Basal West African is a hypothetical line of descent that is no longer extant.
In archaeogenetics, the term Ancient Northern East Asian (ANEA), also known as Northern East Asian (NEA), is used to summarize the related ancestral components that represent the Ancient Northern East Asian peoples, extending from the Baikal region to the Yellow River and the Qinling-Huaihe Line in present-day central China. They are inferred to have diverged from Ancient Southern East Asians (ASEA) around 20,000 to 26,000 BCE.
In archaeogenetics, Ancient Southern East Asian (ASEA), also known as Southern East Asian (sEA), is an ancestral lineage that is represented by individuals from Qihe Cave in Fujian and Liangdao Island in the Taiwan Strait as well as Guangxi. Ancient Southern East Asian ancestry significantly contributed to the genetic makeup of modern populations in East Asia, Mainland Southeast Asia, Insular Southeast Asia, and Oceania, and is commonly associated with the Neolithic expansion of early Austronesian and Austroasiatic speakers that occurred more than 4,000 years ago.
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