Also:
Humans of the same sex are 99.9% genetically identical. There is extremely little variation between human geographical populations and most of the variation that does occur is in the personal level within local areas, and not between populations.
[122][153][154] Of the 0.1% of human genetic differentiation, 85% exists within any randomly chosen local population, be they Italians, Koreans, or Kurds. Two randomly chosen Koreans may be genetically as different as a Korean and an Italian. Any ethnic group contains 85% of the human genetic diversity of the world. Genetic data shows that no matter how population groups are defined, two people from the same population group are about as different from each other as two people from any two different population groups.
[122][155][156][157]
Current genetic research have demonstrated that humans on the
African continent are the most genetically diverse.
[158] There is more human genetic diversity in Africa than anywhere else on Earth. The genetic structure of Africans was traced to 14 ancestral population clusters. Human genetic diversity decreases in native populations with migratory distance from Africa and this is thought to be the result of
bottlenecks during human migration.
[159][160] Humans have lived in Africa for the longest time which allowed accumulation of a higher diversity of genetic mutations in these populations. Only part of Africa’s population migrated out of the continent, bringing just part of the original African genetic variety with them. African populations harbor genetic alleles that are not found in other places of the world. All the common alleles found in populations outside of Africa are found on the African continent.
[122]
Geographical distribution of human variation is complex and constantly shifts through time which reflects complicated human evolutionary history. Most human biological variation is
clinally distributed and blends gradually from an area to the next. Groups of people around the world have different frequencies of
polymorphic genes. Furthermore, different traits are non-concordant and each have different clinal distribution. Adaptability varies both from person to person and from population to population. The most efficient adaptive responses are found in geographical populations where the environmental stimuli are the strongest (e.g.
Tibetans are highly adapted to high altitudes). The clinal geographic genetic variation is further complicated by the migration and mixing between human populations which has been occurring since prehistoric times.
[122][161][162][163][164][165]
Human variation is highly non-concordant: most of the genes do not cluster together and are not inherited together. Skin and hair color are not correlated to height, weight, or athletic ability. Human species do not share the same patterns of variation through geography. Skin color varies with latitude and certain people are tall or have brown hair. There is a statistical correlation between particular features in a population, but different features are not expressed or inherited together. Thus, genes which code for superficial physical traits – such as skin color, hair color, or height – represent a minuscule and insignificant portion of the human genome and do not correlate with genetic affinity. Dark-skinned populations that are found in Africa, Australia, and South Asia are not closely related to each other.
[129][134][164][165][166][167] Even within the same region, physical phenotype is not related to genetic affinity: dark-skinned
Ethiopians are more closely related to light-skinned
Armenians than to dark-skinned
Bantu populations.
[168] Despite
pygmy populations of
South East Asia (
Andamanese) having similar physical features with African pygmy populations such as short stature, dark skin, and curly hair, they are not genetically closely related to these populations.
[169] Genetic variants affecting superficial anatomical features (such as skin color) – from a genetic perspective, are essentially meaningless – they involve a few hundred of the billions of nucleotides in a person's DNA.
[170] Individuals with the same morphology do not necessarily cluster with each other by lineage, and a given lineage does not include only individuals with the same trait complex.
[122][156][171]
Due to practices of group
endogamy, allele frequencies cluster locally around kin groups and lineages, or by national, ethnic, cultural and linguistic boundaries, giving a detailed degree of correlation between genetic clusters and population groups when considering many alleles simultaneously. Despite this, there are no genetic boundaries around local populations that biologically mark off any
discrete groups of humans. Human variation is continuous, with no clear points of demarcation. There are no large clusters of relatively homogeneous people and almost every individual has genetic alleles from several ancestral groups.
[122][163][164][172][173][174][175][176][177][178][179][180]
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