miércoles, 12 de junio de 2013

The human journey



Modern Faces give clues to Ancient Migration

The theories about how anatomically modern humans populated the world are hotly-debated. However, genetic and archaeological evidence points towards an initial migration from southwestern Africa over 100,000 years ago, which spread eastwards out of Africa into the Arabian Peninsula, before a small group began a worldwide dispersal around 60,000 years ago along mainly coastal routes. Do the faces of today’s indigenous people around the world still leave traces of these ancient migrations? During the Upper Palaeolithic humans may have looked quite different from their descendants today; nevertheless, a selection of modern male faces and their common Y-chromosome haplogroups provide a speculative look.

Africa to Europe



San Bushmen


A 2009 study on African genetics located the origin of modern human migration in south-western Africa, near the coastal border of Namibia and Angola. The site is the homeland of the indigenous San people. Studies show that the San carry some of the most divergent (oldest) Y-chromosome haplogroups, specific sub-groups of A and B, the two earliest branches on the human Y-chromosome tree, suggesting they may be descendents of a population ancestral to all modern humans.

Arab – image source: sunya.net
The departure of mankind from Africa involved them crossing the much lower waters of the Red Sea and moving along the green coastlines and interior of Arabia and on to the rest of Eurasia. Supercluster F appeared around 50,000 years ago and is the most common macro-haplogroup outside of Africa with more than 90% of the world’s population.


Anatolian
The DNA of modern Turkish people suggests that a human expansion occurred from 50,000 years ago in the Middle East, through Anatolia, and finally to the rest of Europe. There are many Y-DNA haplogroups present in Turkey; the majority are shared with European, Caucasian and Middle Eastern populations such as haplogroups E3b, G, J, I, R1a, R1b, K and T.

Balkan
In 2002, the oldest modern human remains in Europe were discovered in Romania. They are 30-40,000 years old and are likely to represent among the first people to have entered the continent. Haplogroup I is a Palaeolithic ‘indigenous European’ marker which originated around 20-25,000 years ago around the time of the Last Glacial Maximum. It arose in descendants of Haplogroup IJ men arriving from the Middle East; IJ is up to 40,000 years old, suggesting that IJ colonists formed the first wave into Europe and the now dominant Haplogroup R1 arrived later. The greatest density of Haplogoup I today is to be found in Bosnia (54%) and Herzegovina (71%).

Germanic
In 2007, evidence of the earliest human of occupation Germany was discovered in the form of a 35,000 year old figurine of a mammoth. By 25,000 years ago, the Last Glacial Maximum rendered much of Europe uninhabitable; people took refuge in Iberia, the Balkans, the Ukraine and Italy. As the glaciers receded from about 16,000 years ago, Europe began to be slowly repopulated. Haplogroup I appears to diverge from this point onwards and the re-colonisation of Northern Germany is marked by people bearing the I1 and I2b clades.

Scandinavian
The earliest traces of human occupation in Norway are found along the coast, where the huge ice shelf melted between 13,000 and 10,000 years ago. The oldest finds are stone tools dating from 10,500 years ago, with dwelling sites dating from about 7,000 years ago. Today Haplogroup I1 occurs at greatest frequency in Scandinavia.

Africa to Australia



San Bushmen

Arab - image source: happytouring.com
Archaeological evidence found in Yemen and Oman has raised the possibility that modern humans were established on the southern part of the Arabian Peninsula as far back as 125,000 years ago when the region was relatively lush and habitable and the Red Sea was shallow enough to be crossed on foot or on a small raft. However, genetic evidence suggests that the group who actually went on to people Eurasia came much later, around 60,000 years ago. They probably followed the same migration route around the coastlines from Africa along Yemen and the sea shores of Oman as climatic conditions dictated.

Virumandi Andithevar – Piramalai Kallar
Any archaeological remains of the coastal migration route around India to South East Asia and Australia are now probably under the sea. However, Virumandi Andithevar, of the Piramalai Kallar community from the Tamil Nadu region of southern India, was identified by the Genographic Project as one of the direct descendants of the first modern human settlers in India. His Y-DNA belongs to Haplogroup C and he carries the M130 marker which defines the first migrants to South East Asia and Australia from the African coast 60,000 years ago; more than half of Australian Aborigines also carry the M130 gene.

Vedda – image source: Falco: carnets de Voyages
Modern human remains dated to around 37,000 years ago have been found in Sri Lanka. Later remains from as early as 18,000 years ago suggest a direct line of descent to the indigenous Vedda population which inhabits the area today.

Jarawa – image source vimeo.com
The Andaman Islands are thought to be a key stepping stone in the coastal migration towards Southeast Asia, Japan and Australia. Males of the indigenous Onge and Jarawa tribes almost exclusively belong to Haplogroup D, which is also found in Tibet and Japan. However, this is a subclade which has not been seen outside of the Andamans and highlights the genetic isolation of these tribes, for longer than any known ancient population in the world. Their ancestors are thought to have arrived in the islands 55,000 years ago from coastal India as part of the first wave of modern human expansion out of Africa.

Orang Asli
The geographical position of the Malay Peninsula made it a main thoroughfare on the first wave of migration south. At that time, the much lower sea levels meant that most of maritime Southeast Asia was one land mass; it is known as the lost continent of Sunda. Archaeological evidence of modern human settlement in Peninsular Malaysia is at least 50,000 years old. The mitochondrial DNA (mtDNA) lineages of Malaysia’s indigenous Orang Asli (meaning ‘original men’ in Malay) tribes are also estimated to be around 50,000 years old.

Australian Aborigine
The oldest modern human remains found in Australia have been dated to around 45,000 years ago. Recent genetic studies suggest that Australia was populated by one single migration from Asia as opposed to several waves. Haplogroup C4 is at a high frequency among Australian Aborigines and it has not been found outside of that continent. The first settlers probably made their way southeast along the coast of Sunda until they reached the straits between Sunda and Sahul, the continental land mass that was made up of present-day Australia and New Guinea. They then made the final leg of the journey by sea. Australian Aborigines are the oldest continuous population outside of Africa, the people who have longest occupied their traditional territory, and are the direct descendants of those first explorers.

South East Asia to North America


Orang Rimba – image source: indonesianartandculture.com
While the ancestors of Australian Aborigines headed southeast along the coast of Sunda, others may have eventually turned northeast around 40,000 years ago. The prehistoric northward migration of Haplogroup C in mainland East Asia likely followed the coastline and is consistent with the northward migration of the East Asian Y-chromosome, Haplogroup D.

Ryukyuan – image source: blog.fmokinawa.co.jp
The earliest modern human bones found in Japan are around 32,000 years old. At this time Japan was connected to the continent through several land bridges, notably one linking the Ryukyu Islands to Taiwan and the Korean peninsula, and another one connecting to the Siberian mainland. The Philippines and Indonesia were also connected to the Asian mainland. This allowed migrations from China and Austronesia towards Japan. These first settlers in Japan were the ancestors of the indigenous Ryukyuans (Okinawans). Haplogroups C1 and D2 are unique to Japan and would most likely have come from Austronesia.

Ainu
The ancestors of the indigenous Ainu people settled in Hokkaido, the northernmost of Japan’s islands. Although the Ainu share many physical characteristics with modern Europeans, recent Y-DNA tests have not shown any genetic link. They belong mainly to Haplogroup D2; the only places outside of Japan in which Haplogroup D is common are Tibet and the Andaman Islands.

Itelmen
The Itelmens are the indigenous inhabitants of the Kamchatka Peninsula in east Siberia, which began to be settled about 15,000 years ago. Haplogroup C3 predominates among the Itelmens and is believed to have originated approximately 20,000 years ago in eastern Asia. The Itelmens share their high frequency of C3 Y-DNA with other indigenous Siberian peoples around Kamchatka such as the Koryaks, Evens and Evenks. According to archaeological and genetic evidence, the low sea levels of the Ice Age allowed their ancient nomadic ancestors to traverse and inhabit the land bridge of Beringia that joined Siberia to Alaska for thousands of years, before the glaciers melted and Beringia finally disappeared beneath the sea around 10,000 years ago.

Tanana Athabascan
This small human population survived the Last Glacial Maximum in isolation in Beringia before expanding to populate the Americas sometime after 16,500 years ago as the North American glaciers blocking the way southward melted. Beringia is believed to have supported two distinct migrations into the Americas. The first occurred with populations originating from the Chukotka Peninsula carrying Haplogroup Q1a3a1, which became predominant in indigenous Americans. The second featured minor groups carrying Haplogroup C3b originating from the Kamchatka Peninsula. The oldest existing archaeological site in the Bering region with traces of human occupation is in the Tanana River Valley, Alaska, which is approximately 13,000 years old. The Tanana people belong to the Athabascan group of indigenous North American Indians, and bear equally high frequencies of Haplogroups C3b and Q1a3a1.

Tlicho
Paleo-Indians began to move south and east into Canada; exact dates and routes are still hotly debated. The unglaciated areas of Canada at this time were along the Pacific coastline and east of the Rocky Mountains in the Alberta corridor. The Tlicho, formerly known as the Dogrib, are indigenous to the Northwest Territories in Canada and also hold a high frequency of Haplogroup C3b. This distinct and isolated clade includes almost all of the C3 Y-chromosomes found amongst indigenous peoples of the Americas as far south as Colombia and Venezuela.

Africa to South America





San Bushmen

Arab
The descendants of the small group of migrating modern humans who crossed from Africa into Arabia at the Red Sea gradually expanded and dispersed. The first main division in the expansion likely occurred on the Iranian coast of the Persian Gulf, with some groups continuing to move east while others remained in southern Iran between the Zagros Mountains and the sea.

Iranian
By 50,000 years ago the population that had remained in southern Iran began to expand: to the east into northern India; to the northwest to the Levant; and to the northeast to Central Asia. Because of its pivotal geographic position, Iran likely served as a major crossroads of human migration. This is reflected in the considerable Y-chromosome diversity found in Iranian males.


Niyazov Bey – Kazakh
By 40,000 years ago modern humans had spread to Central Asia following the grasslands resulting from the cooling climate. Niyazov Bey, a Kazakh Turk living in Kazakhstan, was identified by the Genographic Project as one of the direct descendants of the first modern human settlers in Central Asia. His Y-DNA belongs to Haplogroup P and he carries the M45 marker which defines the first migrants to Central Asia from Africa. Haplogroup P is the ancestoral Y-haplogroup of most Europeans and almost all of the indigenous peoples of the Americas; it also contains around one third to two thirds of the males among various populations of Central and Southern Asia.

Selkup
From Central Asia, modern humans headed northeast to populate Siberia. The precise antiquity of modern humans in this vast territory is still not known and archaeological evidence suggests that the settlement of Siberia was a complex and lengthy process. Haplogroup Q defines the route to Siberia; it is a branch of Haplogroup P and is believed to have arisen in Central Asia around 20,000 years ago. The highest frequency of Q in western Siberia today is found among the indigenous Selkup people (66%) who live in the far north. The Selkup language has many words of Iranian origin, indicating an ancient origin there.




Ket
The Ket are thought to be the only survivors of the first ancient nomadic people who originally lived throughout central Siberia. The highest frequencies of Haplogroup Q in Asia are found among the Kets (95%). Subclade Q1 is found mainly in Kets and Selkups in the north. Its age is estimated at 18,000 years old.


Chukchi – image source: National Geographic
The Chukchi are an indigenous people inhabiting the Chukotka Peninsula and the shores of the Chukchi Sea and the Bering Sea region of the Arctic Ocean. In his book The Journey of Man: A Genetic Odyssey, geneticist Spencer Wells shows how a small group of possibly no more than 20 of the Chukchi’s ancestors crossed the land bridge of Beringia sometime after 16,500 years ago. They were the first modern humans to migrate into the Americas and carried the subclade Q1a3a, which eventually became predominant in all indigenous North, Central and South Amerindians.


Eyak Athabascan – image source: – noox-see.livejournal.com
The ancestors of the Athabascan people migrated across the Beringian land bridge into Alaska and northwest Canada. The unglaciated areas of Canada at this time were along the Pacific coastline and east of the Rocky Mountains in the Alberta corridor. Athabascan sub-families such as the Eyak, Tlingit, and Haida settled in the region and eventually spread farther east across Canada. The Y-DNA of the 10,300 year old remains of a human male found in Alaska was found to be in Haplogroup Q1a3a. Modern indigenous Athabascan popuations carry high frequencies of Q1a3a1.


Navajo – image source: native-american-market.com
The modern Navajo Nation occupies all of northeastern Arizona, the southeastern portion of Utah, and northwestern New Mexico and is the largest territory under Native American jurisdiction in the United States. Navajo people speak dialects of the Athabaskan language and are believed to have originated in northwestern Canada and eastern Alaska. The Navajo carry a very high frequency of Haplogroup Q1a3a1 (92%).


Nahua
While the first humans must have passed through Mexico at least 14,000 years ago archaeological evidence of human occupation of the region dates only to around 12,500 years ago. The indigenous Nahuas probably settled much later, originally coming from the deserts of northern Mexico and the southwestern U.S. and migrating into central Mexico in several waves. One migrating Nahua group, the Mexica, settled on an island in Lake Texcoco and became the dominant ethnic group of Mesoamerica. Ruling from their island capital of Tenochtitlan they formed the Aztec empire. The Nahua carry a very high frequency of Haplogroup Q1a3a1a (94%).


Chibcha
Archaeological evidence of continuous occupation of the lower Central American region dates to 11,000 years ago and there is a very likely ancestral link between the earliest Paleo Indians hunter-gatherers and the indigenous Chibcha-speaking peoples in the region. The Chibcha of Colombia seem to have evolved their culture in comparative isolation and carry a 100% frequency of Haplogroup Q1a3a1a.


Amazonian – image source: jeysonstephanie.blogspot.com
The ancestors of the indigenous people of Brazil who settled in the Amazon rainforest probably entered the Amazon River basin from the northwest. The Amazonian Ticuna and Tupi people carry a 100% frequency of Haplogroup Q1a3a1a. The genetic marker M19, detected in 59% of Ticuna men, arose up to 10,000 years ago, suggesting that population isolation and perhaps even the establishment of tribal groups began soon after the initial colonisation of the region.


Tehuelche – image source: alsurinforma.com
An archaeological site at Monte Verde in Patagonia, southern Chile, discovered evidence of human settlement dating back as far as 14,800 years ago; this suggests that the descending generations of the original Beringian Paleo-Indians in the far north had reached the southern end of South America in around 1,000 years. The Patagonian Paleo-Indians were nomadic hunter-gatherers who spent the winters in the lowlands and migrated during the summer to the central highlands of Patagonia and the Andes Mountains. Their descendants are the indigenous Tehuelche people.

Around 11,000 years ago the Selk’nam people started to split off from the ancestral Patagonian group. They became confined to Tierra del Fuego around 6,000 years ago, where they remained until their extinction in the 20th century. The boat- and sea-oriented Yámana and Kawésqar people were also indigenous to this region at the southern tip of South America, but their origins there are unclear.
The Yámana were completely indifferent to the bitter weather around Cape Horn; although they had fire and small shelters, they went about completely naked in the cold and biting wind of Tierra del Fuego, having physically adapted to the harsh climate. The modern population of full-blooded Yámana is down to its last member.
The Kawésqar were a nomadic seafaring people who spent most of their days in their canoes on the waterways of the Brecknock Peninsula. They were also adapted to the cold and rainy conditions and would travel in their canoes naked, oiled with whale blubber. The men sat at the front and hunted sea lions with spears, while the women paddled and the children maintained a continuous fire in a sand pit built in the middle of the canoe. At night they camped on beaches. Their descendants still live in the region, but the full-blooded ethnic lineage is down to its last 15 members.
The Yámana and Kawésqar were physically and culturally distinct from other Native Americans and one suggestion is that may be the descendants of sea-faring Australian Aborigines who colonised South America before the arrival of Amerindians. Geneticists seem divided on the issue. A team of Spanish geneticists in 2004 recovered ancient mtDNA from skeletal samples from Patagonia/Tierra del Fuego. Their analysis apparently revealed their DNA to be of Amerindian origin and linked to populations from Chile and Argentina, but different due to isolation right after their arrival at the southernmost extreme of South America. However, anthropologist George Weber believes that other mtDNA testing shows that they were not Amerindians but were the last surviving remnants of an earlier human migration into the Americas.
In 2009 genetic testing was undertaken on the modern Kawésqar community and on a recently discovered 150 year old mummified body of a Kawésqar Indian. MtDNA analysis showed that the modern Kawésqar were indeed the descendants of the original seafaring populations to inhabit the region. The Kawésqar mummy, however, was a straight match with the inland Aonikenk Indians, a now extinct group of Patagonian nomads. The mummy’s Y-DNA was “clearly Amerindian” (Haplogroup Q), while the modern Kawésqars’ Y-chromosome haplotypes were “unique and differed from the mummified body”; i.e. there was no direct kinship.
Until more conclusive DNA evidence is produced, does the face of a modern Kawésqar man give any clues about their origin?

Kawésqar Fuegian – image source: parquenacionalbernardoohiggins.com

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