Editing Human skin color (section)

== Geographic variation ==
Approximately 10% of the variance in skin color occurs within regions, and approximately 90% occurs between regions.<ref>{{cite journal|title=Apportionment of global human genetic diversity based on craniometrics and skin color |year=2002|last=Relethford|first=J. H.|journal=American Journal of Physical Anthropology|issue=4 |volume=118|pages=393–8|pmid=12124919|doi=10.1002/ajpa.10079|citeseerx=10.1.1.473.5972|s2cid=8717358 }}</ref> Because skin color has been under strong selective pressure, similar skin colors can result from convergent adaptation rather than from genetic relatedness; populations with similar pigmentation may be genetically no more similar than other widely separated groups. Furthermore, in some parts of the world where people from different regions have mixed extensively, the connection between skin color and ancestry has substantially weakened.<ref>{{cite journal|title=Implications of correlations between skin color and genetic ancestry for biomedical research|journal=Nature Genetics|volume=36 |issue=11|year=2004 |pages=S54–S60 |doi=10.1038/ng1440|pmid=15508005|last1=Parra|first1=E. J.|last2=Kittles|first2=R. A. |last3=Shriver|first3=M. D. |s2cid=13712615|doi-access=free}}</ref> In Brazil, for example, skin color is not closely associated with the percentage of recent African ancestors a person has, as estimated from an analysis of genetic variants differing in frequency among continent groups.<ref>{{cite journal|title=Color and genomic ancestry in Brazilians |year=2003|journal=Proceedings of the National Academy of Sciences |issue=1|volume=100|pages=177–182 |doi=10.1073/pnas.0126614100|pmc=140919|pmid=12509516 |last1=Parra|first1=F. C.|last2=Amado|first2=R. C. |last3=Lambertucci|first3=J. R.|last4=Rocha|first4=J. |last5=Antunes|first5=C. M.|last6=Pena|first6=S. D. J. |bibcode=2003PNAS..100..177P |doi-access=free}}</ref>

In general, people living close to the equator are highly darkly pigmented, and those living near the poles are generally very lightly pigmented. The rest of humanity shows a high degree of skin color variation between these two extremes, generally correlating with UV exposure. The main exception to this rule is in the New World, where people have only lived for about 10,000 to 15,000 years and show a less pronounced degree of skin pigmentation.<ref name="LivCol" />

In recent times, humans have become increasingly mobile as a consequence of improved technology, domestication, environmental change, strong curiosity, and risk-taking. Migrations over the last 4000 years, and especially the last 400 years, have been the fastest in human history and have led to many people settling in places far away from their ancestral homelands. This means that skin colors today are not as confined to geographical location as they were previously.<ref name="LivCol" />