''The Journey of Man: A Genetic Odyssey'' is a 2002

book A book is a medium for recording information in the form of writing or images, typically composed of many pages (made of papyrus, parchment, vellum, or paper) bound together and protected by a cover. The technical term for this physi ...

Spencer Wells Spencer Wells (born April 6, 1969) is an American geneticist, anthropologist, author and entrepreneur. He co-hosts The Insight podcast with Razib Khan. Wells led The Genographic Project from 2005 to 2015, as an Explorer-in-Residence at the N ...

, an American

geneticist A geneticist is a biologist or physician who studies genetics, the science of genes, heredity, and variation of organisms. A geneticist can be employed as a scientist or a lecturer. Geneticists may perform general research on genetic processes ...

and anthropologist, in which he uses techniques and theories of

genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar wor ...

and

evolutionary biology Evolutionary biology is the subfield of biology that studies the evolutionary processes ( natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life ...

to trace the geographical dispersal of

early human migrations 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 erect ...

out of

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

. The book was made into a TV documentary in 2003.

Synopsis

According to the recent single-origin hypothesis, human ancestors originated in Africa, and eventually made their way out to the rest of the world. Analysis of the

Y chromosome The Y chromosome is one of two sex chromosomes (allosomes) in therian mammals, including humans, and many other animals. The other is the X chromosome. Y is normally the sex-determining chromosome in many species, since it is the presence or abse ...

is one of the methods used in tracing the history of

early humans ''Homo'' () is the genus that emerged in the (otherwise extinct) genus ''Australopithecus'' that encompasses the extant species ''Homo sapiens'' (modern humans), plus several extinct species classified as either ancestral to or closely relate ...

. 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.Spencer Wells, ''The Journey of Man: A Genetic Odyssey'', p. 55. Random House, 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 Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number o ...

. The San are smaller than the Bantu. They have lighter skins, more tightly curled hair, and they share the

epicanthal fold An epicanthic fold or epicanthus is a skin fold of the upper eyelid that covers the inner corner (medial canthus) of the eye. However, variation occurs in the nature of this feature and the possession of "partial epicanthic folds" or "slight ...

with the people of Central and South East Asia. 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 Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...

and

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...

. There are also peoples in east Africa today who speak substantially different languages that nevertheless share the archaic characteristics of the San language, with 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 marker on the Y chromosome known as M168 (

Haplogroup CT (Y-DNA) Haplogroup CT is a human Y chromosome haplogroup, defining one of the major paternal lineages of humanity. Men who carry the CT clade have Y chromosomes with the SNP mutation M168, along with P9.1 and M294. These mutations are present in all mo ...

).Spencer Wells, ''The Journey of Man: A Genetic Odyssey'', p. 182f. Random House, 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 The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...

including parts of the Arabian Peninsula, the

Middle East The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...

, the

Indian subcontinent The Indian subcontinent is a list of the physiographic regions of the world, physiographical region in United Nations geoscheme for Asia#Southern Asia, Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian O ...

and into

South East Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainland ...

, down into what is now

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

, and eventually reaching Australia. This branch of the human family developed a new marker M130 (

Haplogroup C (Y-DNA) Haplogroup C is a major Y-chromosome haplogroup, defined by UEPs M130/RPS4Y711, P184, P255, and P260, which are all SNP mutations. It is one of two primary branches of Haplogroup CF alongside Haplogroup F. Haplogroup C is found in ancient pop ...

). This first wave appears to have left

dark-skinned people Dark skin is a type of human skin color that is rich in melanin pigments. People with very dark skin are often referred to as "black people", although this usage can be ambiguous in some countries where it is also used to specifically refer to d ...

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 The Semang are an ethnic-minority group of the Malay Peninsula. They live in mountainous and isolated forest regions of Perak, Pahang, Kelantan and Kedah of Malaysia and the southern provinces of Thailand. The Semang are among the different eth ...

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...

, and the

Aeta The Aeta (Ayta ), Agta, or Dumagat, are collective terms for several Filipino indigenous peoples who live in various parts of the island of Luzon in the Philippines. They are considered to be part of the Negrito ethnic groups and share common ...

of the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

.Spencer Wells, ''The Journey of Man: A Genetic Odyssey'', p. 75. Random House, 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 Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...

, north of

Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...

. The lineages that flowed into Central Asia carry M9 ( Haplogroup K (Y-DNA)). 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 (in North American English, known as caribou if wild and ''reindeer'' if domesticated) are deer in the genus ''Rangifer''. For the last few decades, reindeer were assigned to one species, ''Rangifer tarandus'', with about 10 sub ...

. These were the ancestors of Siberian groups such as the

Chukchi people The Chukchi, or Chukchee ( ckt, Ԓыгъоравэтԓьэт, О'равэтԓьэт, ''Ḷygʺoravètḷʹèt, O'ravètḷʹèt''), are a Siberian indigenous people native to the Chukchi Peninsula, the shores of the Chukchi Sea and the Beri ...

, a few of whom still live a nomadic lifestyle today. An even smaller group, estimated at no more than 20, crossed what is now the Bering Sea approximately 15,000 years ago during the last glacial period, and migrated into North America. They are the ancestors of Native Americans, and 800 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 , photo = Sahara real color.jpg , photo_caption = The Sahara taken by Apollo 17 astronauts, 1972 , map = , map_image = , location = , country = , country1 = , ...

, leaving people in areas not separated by the desert to travel and migrate relatively freely.

References

Bibliography

The journey of man: a genetic odyssey
- by

Princeton University Press Princeton University Press is an independent publisher with close connections to Princeton University. Its mission is to disseminate scholarship within academia and society at large. The press was founded by Whitney Darrow, with the financia ...

, 2002 (Digitised online by

Google Books Google Books (previously known as Google Book Search, Google Print, and by its code-name Project Ocean) is a service from Google Inc. that searches the full text of books and magazines that Google has scanned, converted to text using optical ...

External links

Atlas of the Human Journey

Genographic Project The Genographic Project, launched on 13 April 2005 by the National Geographic Society and IBM, was a genetic anthropological study (sales discontinued on 31 May 2019) that aimed to map historical human migrations patterns by collecting and ...

, National Geographic
Journey of Mankind - Genetic Map
-

Bradshaw Foundation The Gwion Gwion rock paintings, Gwion figures, Kiro Kiro or Kujon (previously known as the Bradshaw rock paintings, Bradshaw rock art, Bradshaw figures and the Bradshaws) are one of the two major regional traditions of rock art found in the nort ...

Journey of Mankind -Peopling of the World
PowerPoint with some basic texts in Spanish {{DEFAULTSORT:Journey of Man, The 2002 non-fiction books Human evolution books Genetics books Human migration Books about cultural geography Recent African origin of modern humans 2002 in biology Documentary television shows about evolution

Synopsis

See also

References

Bibliography

External links