The Journey of Man: A Genetic Odyssey
Encyclopedia
The Journey of Man: A Genetic Odyssey is a book
by Spencer Wells
, an American
geneticist
and anthropologist, in which he uses techniques and theories of genetics
and evolutionary biology to trace the geographical dispersal of early human migrations
out of Africa
. The book was made into a TV documentary in 2003.
, human ancestors originated in Africa, and eventually made their way out to the rest of the world. Analysis of the Y chromosome
is one of the methods used in tracing the history of early humans. Thirteen genetic markers on the Y-chromosome differentiate populations of human beings.
It is believed, on the basis of genetic evidence, that all human beings in existence now descend from one single man who lived in Africa about 60,000 years ago. The earliest groups of humans are believed to find their present-day descendants among the San
people, a group that is now found in western southern Africa
. The San are smaller than the Bantu. They have lighter skins, more tightly curled hair, and they share the epicanthal fold
with the people of East Asia, such as the Chinese
and Japanese
.
Southern and eastern Africa are believed to originally have been populated by people akin to the San. Since that early time much of their range has been taken over by the Bantu. Skeletal remains of these ancestral people are found in Paleolithic
sites in Somalia
and Ethiopia
. There are also peoples in east Africa
today who speak substantially different languages that nevertheless share the archaic characteristics of the San language, its distinctive repertoire of click and pop sounds. These are the only languages in the entire world that use these sounds in speech.
As humans migrated out of Africa, they all carried a genetic feature on the Y chromosome known as M168
.
The first wave of migration out of Africa stayed close to the oceans shores, tracing a band along the coastal areas of the Indian Ocean
including parts of the Arabian Peninsula
, the Middle East
, the Indian subcontinent
and into South East Asia, down into what is now Indonesia
, and eventually reaching Australia
. This branch of the human family developed a new marker, M130
.
This first wave appears to have left dark-skinned people
along its path, including isolated groups of dark-skinned people in south east Asia such as the aboriginal population of the Andaman Islands
(around 400 km off the west coast of Thailand), the Semang
of Malaysia, and the Aeta
of the Philippines
.
The second wave of migration took a more northerly course, splitting somewhere in the area around what is now called Syria
to sweep to interior Asia, where it split several more times in Central Asia
, north of Afghanistan
. The lineages that flowed into Central Asia carry M9
. Other markers were added after the migration paths went on in several different directions from Central Asia.
From Central Asia, a small group migrated towards the northeast, following reindeer
. These were the Chukchi people
, a few of whom still live a nomadic lifestyle today. An even smaller group, estimated at no more than 20 Chukchis, crossed what is now the Bering Sea
approximately 13,000 years ago during the last glacial period, and migrated into North America. They are the ancestors of Native Americans
, and 800 hundred years later, they had reached as far as South America.
The African diaspora is believed to have begun some 50,000 years ago, long enough for many changes to have occurred in humans remaining in Africa. The genetic trends reported involve humans who left Africa, and their genetic histories. The diversity found outside of Africa may well have been accentuated since populations migrating to new hunting grounds would rarely have had individuals moving backwards into previously settled regions. But within Africa, isolation would have been geographically aided primarily by the Sahara Desert, leaving people in areas not separated by the desert to travel and migrate relatively freely.
Book
A book is a set or collection of written, printed, illustrated, or blank sheets, made of hot lava, paper, parchment, or other materials, usually fastened together to hinge at one side. A single sheet within a book is called a leaf or leaflet, and each side of a leaf is called a page...
by Spencer Wells
Spencer Wells
Spencer Wells is a geneticist and anthropologist, an at the National Geographic Society, and Frank H.T. Rhodes Class of '56 Professor at Cornell University. He leads The Genographic Project.-Education:...
, an American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
geneticist
Geneticist
A geneticist is a biologist who studies genetics, the science of genes, heredity, and variation of organisms. A geneticist can be employed as a researcher or lecturer. Some geneticists perform experiments and analyze data to interpret the inheritance of skills. A geneticist is also a Consultant or...
and anthropologist, in which he uses techniques and theories of genetics
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
and evolutionary biology to trace the geographical dispersal of early human migrations
Early human migrations
Early human migrations began when Homo erectus first migrated out of Africa over the Levantine corridor and Horn of Africa to Eurasia about 1.8 million years ago, a migration probably sparked by the development of language Early human migrations began when Homo erectus first migrated out of Africa...
out of Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. The book was made into a TV documentary in 2003.
Synopsis
According to the recent single origin hypothesisRecent African origin of modern humans
In paleoanthropology, the recent African origin of modern humans is the most widely accepted model describing the origin and early dispersal of anatomically modern humans...
, human ancestors originated in Africa, and eventually made their way out to the rest of the world. Analysis of the Y chromosome
Y chromosome
The Y chromosome is one of the two sex-determining chromosomes in most mammals, including humans. In mammals, it contains the gene SRY, which triggers testis development if present. The human Y chromosome is composed of about 60 million base pairs...
is one of the methods used in tracing the history of early humans. Thirteen genetic markers on the Y-chromosome differentiate populations of human beings.
It is believed, on the basis of genetic evidence, that all human beings in existence now descend from one single man who lived in Africa about 60,000 years ago. The earliest groups of humans are believed to find their present-day descendants among the San
Bushmen
The indigenous people of Southern Africa, whose territory spans most areas of South Africa, Zimbabwe, Lesotho, Mozambique, Swaziland, Botswana, Namibia, and Angola, are variously referred to as Bushmen, San, Sho, Barwa, Kung, or Khwe...
people, a group that is now found in western southern Africa
Southern Africa
Southern Africa is the southernmost region of the African continent, variably defined by geography or geopolitics. Within the region are numerous territories, including the Republic of South Africa ; nowadays, the simpler term South Africa is generally reserved for the country in English.-UN...
. The San are smaller than the Bantu. They have lighter skins, more tightly curled hair, and they share the epicanthal fold
Epicanthal fold
An epicanthic fold, epicanthal fold, or epicanthus is a skin fold of the upper eyelid, covering the inner corner of the eye....
with the people of East Asia, such as the Chinese
Chinese people
The term Chinese people may refer to any of the following:*People with Han Chinese ethnicity ....
and Japanese
Japanese people
The are an ethnic group originating in the Japanese archipelago and are the predominant ethnic group of Japan. Worldwide, approximately 130 million people are of Japanese descent; of these, approximately 127 million are residents of Japan. People of Japanese ancestry who live in other countries...
.
Southern and eastern Africa are believed to originally have been populated by people akin to the San. Since that early time much of their range has been taken over by the Bantu. Skeletal remains of these ancestral people are found in Paleolithic
Paleolithic
The Paleolithic Age, Era or Period, is a prehistoric period of human history distinguished by the development of the most primitive stone tools discovered , and covers roughly 99% of human technological prehistory...
sites in Somalia
Somalia
Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...
and Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
. There are also peoples in east Africa
East Africa
East Africa or Eastern Africa is the easterly region of the African continent, variably defined by geography or geopolitics. In the UN scheme of geographic regions, 19 territories constitute Eastern Africa:...
today who speak substantially different languages that nevertheless share the archaic characteristics of the San language, its distinctive repertoire of click and pop sounds. These are the only languages in the entire world that use these sounds in speech.
As humans migrated out of Africa, they all carried a genetic feature on the Y chromosome known as M168
Haplogroup CT (Y-DNA)
In human genetics, Haplogroup CT is a Y-chromosome haplogroup, defining one of the major lines of common ancestry of humanity along father-to-son male lines.Men within this haplogroup have Y chromosomes with the SNP mutation M168, along with P9.1 and M294...
.
The first wave of migration out of Africa stayed close to the oceans shores, tracing a band along the coastal areas of the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
including parts of the Arabian Peninsula
Arabian Peninsula
The Arabian Peninsula is a land mass situated north-east of Africa. Also known as Arabia or the Arabian subcontinent, it is the world's largest peninsula and covers 3,237,500 km2...
, the Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
, the Indian subcontinent
Indian subcontinent
The Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...
and into South East Asia, down into what is now Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, and eventually reaching Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. This branch of the human family developed a new marker, M130
Haplogroup C (Y-DNA)
In human genetics, Haplogroup C is a Y-chromosome haplogroup, defined by UEPs M130/RPS4Y711, M216, P184, P255, and P260, which are all SNP mutations. It is a sibling clade of Haplogroup F, within the more ancient grouping of Haplogroup CF...
.
This first wave appears to have left dark-skinned people
Black people
The term black people is used in systems of racial classification for humans of a dark skinned phenotype, relative to other racial groups.Different societies apply different criteria regarding who is classified as "black", and often social variables such as class, socio-economic status also plays a...
along its path, including isolated groups of dark-skinned people in south east Asia such as the aboriginal population of the Andaman Islands
Andaman Islands
The Andaman Islands are a group of Indian Ocean archipelagic islands in the Bay of Bengal between India to the west, and Burma , to the north and east...
(around 400 km off the west coast of Thailand), the Semang
Semang
The Semang are a Negrito ethnic group of the Malay Peninsula. Lowland Semang tribes are also known as Sakai, although this term is considered to be derogatory by the Semang people. They are probably the indigenous peoples of this area. They have been recorded to have lived here since before the...
of Malaysia, and the Aeta
Aeta
The Aeta , Agta or Ayta are an indigenous people who live in scattered, isolated mountainous parts of Luzon, Philippines. They are considered to be Negritos, who are dark to very dark brown-skinned and tend to have features such as a small stature, small frame, curly to kinky afro-like textured...
of the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
.
The second wave of migration took a more northerly course, splitting somewhere in the area around what is now called Syria
Syria
Syria , officially the Syrian Arab Republic , is a country in Western Asia, bordering Lebanon and the Mediterranean Sea to the West, Turkey to the north, Iraq to the east, Jordan to the south, and Israel to the southwest....
to sweep to interior Asia, where it split several more times in Central Asia
Central Asia
Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...
, north of Afghanistan
Afghanistan
Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...
. The lineages that flowed into Central Asia carry M9
Haplogroup K (Y-DNA)
In human genetics, Haplogroup K is a Human Y-chromosome DNA haplogroup. This haplogroup is a descendant of Haplogroup IJK. Its major descendant haplogroups are Haplogroup LT and Haplogroup K...
. Other markers were added after the migration paths went on in several different directions from Central Asia.
From Central Asia, a small group migrated towards the northeast, following reindeer
Reindeer
The reindeer , also known as the caribou in North America, is a deer from the Arctic and Subarctic, including both resident and migratory populations. While overall widespread and numerous, some of its subspecies are rare and one has already gone extinct.Reindeer vary considerably in color and size...
. These were the Chukchi people
Chukchi people
The Chukchi, or Chukchee , ) are an indigenous people inhabiting the Chukchi Peninsula and the shores of the Chukchi Sea and the Bering Sea region of the Arctic Ocean within the Russian Federation. They speak the Chukchi language...
, a few of whom still live a nomadic lifestyle today. An even smaller group, estimated at no more than 20 Chukchis, crossed what is now the Bering Sea
Bering Sea
The Bering Sea is a marginal sea of the Pacific Ocean. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves....
approximately 13,000 years ago during the last glacial period, and migrated into North America. They are the ancestors of Native Americans
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
, and 800 hundred years later, they had reached as far as South America.
The African diaspora is believed to have begun some 50,000 years ago, long enough for many changes to have occurred in humans remaining in Africa. The genetic trends reported involve humans who left Africa, and their genetic histories. The diversity found outside of Africa may well have been accentuated since populations migrating to new hunting grounds would rarely have had individuals moving backwards into previously settled regions. But within Africa, isolation would have been geographically aided primarily by the Sahara Desert, leaving people in areas not separated by the desert to travel and migrate relatively freely.
See also
- Recent African origin of modern humansRecent African origin of modern humansIn paleoanthropology, the recent African origin of modern humans is the most widely accepted model describing the origin and early dispersal of anatomically modern humans...
- Human Y-chromosome DNA haplogroup for the male lineage
- Human mitochondrial DNA haplogroup for the female lineage
- Mitochondrial EveMitochondrial EveIn the field of human genetics, Mitochondrial Eve refers to the matrilineal "MRCA" . In other words, she was the woman from whom all living humans today descend, on their mother's side, and through the mothers of those mothers and so on, back until all lines converge on one person...
External links
- Atlas of the Human Journey, Genographic Project, National Geographic
- Journey of Mankind - Genetic Map - Bradshaw FoundationJohn Robinson (sculptor)John Robinson was a British sculptor and co-founder of the . Accounts of his work may be seen at the , the website of the and the June and July 2007, issues of...
- Journey of Mankind -Peopling of the World PowerPoint with some basic texts in Spanish