The Variability of Hybrid PopulationsPosted in Anthropology, Articles, Media Archive on 2010-11-03 18:59Z by Steven |
The Variability of Hybrid Populations
American Journal of Physical Anthropology
Volume 16, Issue 3 (January/March 1932)
pages 283–307
DOI: 10.1002/ajpa.1330160312
K. Wagner
Department of Anatomy
University of Oslo
On the assumption of mendelian inheritance it should be expected that hybrid populations, apart from the first generation of crossing, must show an increased variability as compared with the original ‘races’ that entered into the mixture. Assuming that the characters investigated are genetically very complex, i.e., that there is pronounced polymeria, the difference in variability between hybrid populations and the relatively ‘pure’ races would no doubt be diminished, but not entirely eliminated. The chances for segregation of a polymeric character are, it is true, very small and diminish greatly with an increasing number of fundamental factors, so that a very large body of hybrid material would be required in order to be able to count upon a variation effect, but polymeric characters in this absolute sense are certainly exceptional. If the complete emergence of a character is due to combinations of the factors abc, then ab, ac, or be will in many, perhaps in most, cases have some, effect. Neither does dominance play any decisive role for the variability rule here laid down, as the segregation of recessive types must bring about a considerable increase in the variability of hybrid populations, and, quite apart from this, it may be said that absolute dominance hardly comes into consideration as regards most of the anthropological characters.
Here, as so often elsewhere, changes of environment may have a disturbing influence, but these must necessarily be disregarded in a theoretical consideration of the matter. In case the racial crossing took place far back in time, it might be imagined that the high degree of heterozygosis occasioned…
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