Paleoserology

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Description

Progressively changing zones of degree difference in frequency of a trait with movement from one region to another. The gradual decrease in frequency of the B blood allele going west in Europe is an example of such a gradation or clinal distribution.

http://anthro.palomar.edu/vary/images/map_of_B_blood_clines_in_Europe.gif

Clines of group B distribution Source

Discussion

'Discontinuous distribution' is the geographic distribution of a trait such that it appears in high or low frequencies in various areas with little or no gradation between them.

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