Sexual reproduction between two populations reduces the
genetic distance between the populations. During the
Age of Discovery which began in the early
15th century, European explorers sailed all across the globe reaching all the major continents. In the process they came into contact with many populations that had been isolated for thousands of years. The
Tasmanian Aboriginals were one of the most isolated groups on the planet. Many died from disease and conflict, but a number of their descendants survive today as multiracial people of Tasmanian and European descent. This is an example of how modern migrations may reduce the
genetic divergence of the humans, which would usually lead to
speciation.
New World demographics were radically changed within a short time following the voyage of
Columbus. A 2003 study by
Mark D. Shriver of a European-American sample found that the average admixture in the individuals who participated was 0.7% African and 3.2% Native American. However, 70% of the sample had no African admixture. The other 30% had African admixture ranging from 2% to 20% with an average of 2.3%. By extrapolating these figures to the whole population some scholars suggest that up to 74 million European-Americans may have African admixture in the same range (2–20%). Recently J.T. Frudacas, Shriver's partner in DNA Print Genomics, contradicted him stating "Five percent of European Americans exhibit some detectable level of African ancestry." Historians estimate that 58% of enslaved women in the United States aged 15–30 years were sexually assaulted by their slave owners and other White men. One such slave owner,
Thomas Jefferson, fathered his slave
Sally Hemings' child. While publicly opposed to race mixing, in his
Notes on the State of Virginia published in 1785, Jefferson wrote: "The improvement of the blacks in body and mind, in the first instance of their mixture with the whites, has been observed by every one, and proves that their inferiority is not the effect merely of their condition of life". Within the African-American population, the amount of African admixture is directly correlated with darker skin since less selective pressure against dark skin is applied within the group of "non-passing" individuals. Thus, African-Americans may have a much wider range of African admixture (>0–100%), whereas European-Americans have a lower range (2–20%). , Francois, paying $600 in trade goods for an Indian woman to be his wife, . A statistical analysis done in 1958 using historical census data and historical data on immigration and birth rates concluded that 21% of the white population had black ancestors. The growth in the White population could not be attributed to births in the White population and immigration from Europe alone, but had received significant contribution from the African American population as well. The author states in 1958: A 2003 study on Y-chromosomes and mtDNA detected no African admixture in the European-Americans who took part in it. The sample included 628 European-American Y-chromosomes and mtDNA from 922 European-Americans According to a genome-wide study by 23andMe, White Americans (European Americans) who participated were: "98.6 percent European, 0.19 percent African and 0.18 percent Native American on average." However, the range varies widely from country to country in
Latin America with some countries having significantly larger
Amerindian minorities. , 18th century|309x309px The early conquest of Latin America was primarily carried out by male soldiers and sailors from
Spain and
Portugal. Since they carried very few European women on their journeys the new settlers married and fathered children with Amerindian women and also with women taken by force from
Africa. This process of miscegenation was even encouraged by the
Spanish Monarchy. Many Amerindian languages were lost as mixed race offspring adopted
Spanish and
Portuguese as their first languages. Only towards the end of the 19th century and beginning of the 20th century did large numbers of Europeans begin to migrate to
South America and consequently altering its
demographics. In addition many
Africans were shipped to regions all over the Americas and were present in many of the early voyages of the
conquistadors.
Brazil has the largest population of African descendants outside Africa. Other countries such as
Jamaica,
Cuba,
Puerto Rico,
Dominican Republic,
Haiti,
Venezuela,
Colombia, and
Ecuador still have sizeable populations identified as
Black. However countries such as
Argentina do not have a visible African presence today. Census information from the early 19th century shows that people categorized as Black made up to 30% of the population, or around 400,000 people. Though almost completely absent today, their contribution to Argentine culture is significant and include the
tango, the
milonga and the
zamba, words of
Bantu origin. The ideology of whitening encouraged non-whites to seek white or lighter skinned partners. This dilution of non-white admixture would be beneficial to their offspring as they would face less stigmatization and find it easier to assimilate into mainstream society. After successive generations of European gene flow, non-white admixture levels would drop below levels at which skin color or physical appearance is not affected thus allowing individuals to identify as White. In many regions, the native and black populations were simply overwhelmed by a succession of waves of European immigration. Historians and scientists are thus interested in tracing the fate of Native Americans and Africans from the past to the future. The questions remain about what proportion of these populations simply died out and what proportion still has descendants alive today including those who do not racially identify themselves as their ancestors would have. Admixture testing has thus become a useful objective tool in shedding light on the demographic history of Latin America.
Recent studies , 1763, Colonial Mexico. Unlike the United States, there were no anti-miscegenation policies in Latin America. Though still a racially stratified society there were no significant barriers to gene flow between the three populations. As a result, admixture profiles are a reflection of the colonial populations of Africans, Europeans and Amerindians. The pattern is also sex biased in that the African and Amerindian maternal lines are found in significantly higher proportions than African or Amerindian Y chromosomal lines. This is an indication that the primary mating pattern was that of European males with Amerindian or African females. According to the study more than half the White populations of the Latin American countries studied have some degree of either Native American or African admixture (
MtDNA or
Y chromosome). In countries such as
Chile and
Colombia almost the entire white population was shown to have some non-white admixture.
Frank Moya Pons, a
Dominican historian documented that Spanish colonists intermarried with
Taíno women, and, over time, these mestizo descendants intermarried with Africans, creating a tri-racial Creole culture. 1514 census records reveal that 40% of Spanish men in the colony of
Santo Domingo had Taíno wives. A 2002 study conducted in
Puerto Rico suggests that over 61% of the population possess Amerindian mtDNA.
Admixture in the Philippines Historically, admixture has been a common phenomenon in the Philippines. The Philippines were originally settled by
Australoid peoples called
Negritos which now form the country's aboriginal community. Admixture occurred between this earlier group and the mainstream
Malayo-Polynesian population. There has been
Indian migration to and influence in the Philippines since the precolonial era. About 25% of the words in the
Tagalog language are
Sanskrit terms and about 5% of the country's population possess Indian ancestry from antiquity. There has been a
Chinese presence in the
Philippines since the 9th century. However, large-scale migrations of Chinese to the Philippines only started during the Spanish colonial era, when the world market was opened to the Philippines. It is estimated that among
Filipinos, 10%–20% have some Chinese ancestry and 1.5% are "full-blooded" Chinese. According to the American
anthropologist Dr. H. Otley Beyer, the ancestry of
Filipinos is 2%
Arab. This dates back to when Arab traders intermarried with the local
Malay Filipino female populations during the
pre-Spanish history of the Philippines. A recent genetic study by
Stanford University indicates that at least 3.6% of the population are
European or of part European descent from both
Spanish and United States colonization.
Admixture among the Romani people Genetic evidence has shown that the
Romani people originated from the
Indian subcontinent and mixed with the local populations in
Central Asia, the
Middle East, and
Europe. In the 1990s, it was discovered that Romani populations carried large frequencies of particular
Y chromosomes (inherited paternally) that otherwise exist only in populations from
South Asia, in addition to fairly significant frequencies of particular
mitochondrial DNA (inherited maternally) that is rare outside South Asia. 47.3% of Romani males carry Y chromosomes of
haplogroup H-M82 which is rare outside of the Indian subcontinent. Mitochondrial
haplogroup M, most common in Indian subjects and rare outside Southern Asia, accounts for nearly 30% of Romani people. Moreover, a form of the inherited disorder
congenital myasthenia is found in Romani subjects. This form of the disorder, caused by the 1267delG mutation, is otherwise only known in subjects of Indian ancestry. This is considered to be the best evidence of the Indian ancestry of the Romanies. The Romanis have been described as "a conglomerate of genetically isolated founder populations", while a number of common Mendelian disorders among Romanies from all over Europe indicates "a common origin and founder effect". A study from 2001 by Gresham et al. suggests "a limited number of related founders, compatible with a small group of migrants splitting from a distinct caste or tribal group". The same study found that "a single lineage ... found across Romani populations, accounts for almost one-third of Romani males. A similar preservation of a highly resolved male lineage has been reported elsewhere only for Jewish priests".
Coloured was a legally defined
racial classification during
apartheid. In the
Western Cape, a distinctive
Cape Coloured and affiliated
Cape Malay culture developed. In other parts of Southern Africa, people classified as Coloured were usually the descendants of individuals from two distinct ethnicities. Genetic studies suggest the group has the highest levels of mixed ancestry in the world. ==See also==