Haplogroup D1 (Y-DNA)
Encyclopedia
In human genetics
Human genetics
Human genetics describes the study of inheritance as it occurs in human beings. Human genetics encompasses a variety of overlapping fields including: classical genetics, cytogenetics, molecular genetics, biochemical genetics, genomics, population genetics, developmental genetics, clinical genetics,...

, Haplogroup D1 (M15) is a Y-chromosome DNA haplogroup. Haplogroup D1 is a descendant branch of the greater Haplogroup D
Haplogroup D (Y-DNA)
In human genetics, Haplogroup D is a Y-chromosome haplogroup. Both D and E lineages also exhibit the single-nucleotide polymorphism M168 which is present in all Y-chromosome haplogroups except A and B, as well as the YAP unique-event polymorphism, which is unique to Haplogroup...

.

Its phylogenetically closest relatives are found among the peoples of Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, 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...

, and 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...

 in the Bay of Bengal
Bay of Bengal
The Bay of Bengal , the largest bay in the world, forms the northeastern part of the Indian Ocean. It resembles a triangle in shape, and is bordered mostly by the Eastern Coast of India, southern coast of Bangladesh and Sri Lanka to the west and Burma and the Andaman and Nicobar Islands to the...

. It is more distantly related to the Haplogroup E
Haplogroup E (Y-DNA)
In human genetics, Haplogroup E is a human Y-chromosome DNA haplogroup. Haplogroup E is one of the two main branches of the older Haplogroup DE, the other main branch being haplogroup D. The E clade is divided into two subclades: E1 and E2 .-Origins:Underhill et al. proposed that haplogroup E...

, whose sub-clades are common throughout 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...

, West Asia, and Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

.

Distribution

Haplogroup D1 is widely distributed throughout populations that dwell to the northwest, north, northeast, east, and southeast of the Himalaya
Himalayas
The Himalaya Range or Himalaya Mountains Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range in Asia, separating the Indian subcontinent from the Tibetan Plateau...

. It is not found among the populations of India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 to the south and southwest. The distribution of Haplogroup D1 in Southeast Asia is also very limited, as it is found there only at low frequency and only among populations that speak Tibeto-Burman
Tibeto-Burman languages
The Tibeto-Burman languages are the non-Chinese members of the Sino-Tibetan language family, over 400 of which are spoken thoughout the highlands of southeast Asia, as well as lowland areas in Burma ....

 or Miao–Yao languages, which have ancestral ties to the north.

The distribution of Haplogroup D1 is much more regular in the north, as it is found among nearly all the populations of Central Asia and Northeast Asia south of the Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

n border, although generally at a low frequency of 2% or less. A dramatic spike in the frequency of Haplogroup D1 occurs as one approaches the Qinghai-Tibetan Plateau
Tibetan Plateau
The Tibetan Plateau , also known as the Qinghai–Tibetan Plateau is a vast, elevated plateau in Central Asia covering most of the Tibet Autonomous Region and Qinghai, in addition to smaller portions of western Sichuan, southwestern Gansu, and northern Yunnan in Western China and Ladakh in...

 of western China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

: among some local populations in Qinghai
Qinghai
Qinghai ; Oirat Mongolian: ; ; Salar:) is a province of the People's Republic of China, named after Qinghai Lake...

, it has been found to reach as high as 100%. Its frequency gradually fades as one travels south through the territory of the Tibetan people
Tibetan people
The Tibetan people are an ethnic group that is native to Tibet, which is mostly in the People's Republic of China. They number 5.4 million and are the 10th largest ethnic group in the country. Significant Tibetan minorities also live in India, Nepal, and Bhutan...

s, as Haplogroup O3
Haplogroup O3 (Y-DNA)
In human genetics, Haplogroup O3 is a Y-chromosome haplogroup.-Origins:Haplogroup O3 is a descendant haplogroup of haplogroup O. Some researchers believe that it first appeared in China approximately 10,000 years ago, while others believe it to have had an origin in Southeast Asia approximately...

, which is the most common haplogroup among the Han Chinese
Han Chinese
Han Chinese are an ethnic group native to China and are the largest single ethnic group in the world.Han Chinese constitute about 92% of the population of the People's Republic of China , 98% of the population of the Republic of China , 78% of the population of Singapore, and about 20% of the...

 and also generally found among Southeast Asian populations, becomes dominant. Haplogroup D1 continues to occur at an overall very low frequency among the Han people to the east; however, there are some indications that the frequency of D1 among the Hans may vary significantly between localities. A secondary, minor spike in the frequency of Haplogroup D1 occurs again in Korea
Korea
Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...

, where it may reach as high as 5% to 8%; this somewhat heightened frequency does not stretch into Manchuria to the north or Japan to the east, which may corroborate historical accounts of immigration from the country of Qin
Qin (state)
The State of Qin was a Chinese feudal state that existed during the Spring and Autumn and Warring States Periods of Chinese history...

 in the far west of ancient China to the country of Jinhan
Jinhan confederacy
Jinhan was a loose confederacy of chiefdoms that existed from around the 1st century BC to the 4th century AD in the southern Korean peninsula, to the east of the Nakdong River valley, Gyeongsang Province. Jinhan was one of the Samhan , along with Byeonhan and Mahan...

, which is believed to have been located somewhere in the southern half of the Korean Peninsula. Ancient Chinese historians are known for their habit of drawing what often seem to be forced connections between contemporary peoples and putative ancestors of misty antiquity, and the comments about immigration from Qin to Jinhan might have been motivated by the similarity that the ancient central Chinese perceived between the languages of Qin and Jinhan. Nevertheless, on this occasion the genetic evidence seems to provide the story with some independent corroboration.

As for the ultimate origin of Haplogroup D1, one can only speculate that it might share a recent common ancestor with the Haplogroup D* (M174) Y-chromosomes that are found at a vanishingly low frequency among modern populations of 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...

.

In regards to the ethnic affiliation of the original carriers of Haplogroup D1, it is notable that Haplogroup D1 Y-chromosomes have not been found to occur at all among many populations of Tibeto-Burman speakers, but Y-chromosomes belonging to the Haplogroup O3a5-M134 clade are commonly found among all Tibeto-Burman-speaking populations outside of Qinghai in addition to being the modal haplogroup among speakers of Sino-Tibetan languages
Sino-Tibetan languages
The Sino-Tibetan languages are a language family comprising, at least, the Chinese and the Tibeto-Burman languages, including some 250 languages of East Asia, Southeast Asia and parts of South Asia. They are second only to the Indo-European languages in terms of the number of native speakers...

 in general, which suggests that the Haplogroup D1 Y-chromosomes found at high frequency among the populations of the Qinghai-Tibetan Plateau may reflect:
(1) A severe founder effect
Founder effect
In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, using existing theoretical work by those such as Sewall...

 and/or genetic drift
Genetic drift
Genetic drift or allelic drift is the change in the frequency of a gene variant in a population due to random sampling.The alleles in the offspring are a sample of those in the parents, and chance has a role in determining whether a given individual survives and reproduces...


(2) Descent from a Tibeticized Paleolithic substrate distantly related to modern populations of Central and/or Northeast Asia
(3) A massive incursion of foreign Y-chromosomes belonging to a now linguistically extinct tribe of ultimately Central Asian or Northeast Asian derivation, subsequent to the establishment of Sino-Tibetan-speaking Neolithic populations in the general area.
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