Trinicenter TrinbagoPan RootsWomen HowComYouCom

Genes, peoples, and languages
Posted: Sunday, July 29, 2001

The genetic history of a group of populations is usually analyzed by reconstructing a tree of their origins. Reliability of the reconstruction depends on the validity of the hypothesis that genetic differentiation of the populations is mostly due to population fissions followed by independent evolution. If necessary, adjustment for major population admixtures can be made. Dating the fissions requires comparisons with paleoanthropological and paleontological dates, which are few and uncertain.

A method of absolute genetic dating recently introduced uses mutation rates as molecular clocks; it was applied to human evolution using microsatellites, which have a sufficiently high mutation rate. Results are comparable with those of other methods and agree with a recent expansion of modern humans from Africa. An alternative method of analysis, useful when there is adequate geographic coverage of regions, is the geographic study of frequencies of alleles or haplotypes.

As in the case of trees, it is necessary to summarize data from many loci for conclusions to be acceptable. Results must be independent from the loci used. Multivariate analyses like principal components or multidimensional scaling reveal a number of hidden patterns and evaluate their relative importance. Most patterns found in the analysis of human living populations are likely to be consequences of demographic expansions, determined by technological developments affecting food availability, transportation, or military power.

During such expansions, both genes and languages are spread to potentially vast areas. In principle, this tends to create a correlation between the respective evolutionary trees. The correlation is usually positive and often remarkably high. It can be decreased or hidden by phenomena of language replacement and also of gene replacement, usually partial, due to gene flow.

Print Printer friendly version
Email page Send page by E-Mail


Previous Page | Zimbabwe Watch | Historical Views | Home     Back to top

Page 1 - Page 2 - Page 3 - Page 4 - Page 5 - Page 6

NOTICE: All articles are the copyright property of the writers. In accordance with Title 17 U.S.C., section 107, some material on this site is provided without permission from the copyright owner, only for purposes of criticism, comment, scholarship and research under the "fair use" provisions of federal copyright laws. Visit: for more details. If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner. - Another 100% non-profit Website
Africa Speaks

Map of Africa

Black African Focus

U.S Coup in Haiti

Zimbabwe: Land Reform and Mugabe

Trinidad and Tobago News


Message Board