Publication Date:
1993-01-29
Description:
Geographic expansions are caused by successful innovations, biological or cultural, that favor local growth and movement. They have had a powerful effect in determining the present patterns of human genetic geography. Modern human populations expanded rapidly across the Earth in the last 100,000 years. At the end of the Paleolithic (10,000 years ago) only a few islands and other areas were unoccupied. The number of inhabitants was then about one thousand times smaller than it is now. Population densities were low throughout the Paleolithic, and random genetic drift was therefore especially effective. Major genetic differences between living human groups must have evolved at that time. Population growths that began afterward, especially with the spread of agriculture, progressively reduced the drift in population and the resulting genetic differentiation. Genetic traces of the expansions that these growths determined are still recognizable.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cavalli-Sforza, L L -- Menozzi, P -- Piazza, A -- GM 10452/GM/NIGMS NIH HHS/ -- GM 20467/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1993 Jan 29;259(5095):639-46.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Genetics Department, Stanford University, CA 94305.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8430313" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
*Biological Evolution
;
Chromosome Mapping
;
*Geography
;
*Hominidae/genetics
;
Humans
;
Paleontology
;
*Population Density
;
*Population Growth
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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