Hostname: page-component-7479d7b7d-wxhwt Total loading time: 0 Render date: 2024-07-11T13:16:08.301Z Has data issue: false hasContentIssue false

Genetic divergence in M. Vetukhiv's experimental populations of Drosophila pseudoobscura 3. Divergence in Body Size

Published online by Cambridge University Press:  14 April 2009

Wyatt W. Anderson
Affiliation:
The Rockefeller University, New York City

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

1. Six initially identical populations of Drosophila pseudoobscura have been maintained in population cages for 7 years. Two populations have been kept at 16°C, two at 25°C, and two at 27°C.

2. One and a half years after the start, there was no significant genetic divergence in body size among the populations. When the populations were about 6 years old, a striking genetic divergence in body size was found. The genetic difference between the populations having the smallest and the largest mean sizes is over half the total phenotypic change in size between the two extreme temperatures at which the populations were kept. The populations kept at the lower temperature have genetically larger flies than the populations kept at the higher temperatures.

3. Accompanying the changes in body size were changes in the time of develop ment from egg to adult, the faster developers being the larger flies.

4. The F1 hybrids from crossses between Vetukhiv's populations showed non-additivity of the genes for body size, the F1's in most cases being significantly larger than the midparent. There was no change in variability of body size in the F1 or F2 hybrids.

5. The temperature-directed selection for body size found in Vetukhiv's experimental populations may well be similar in kind to that which has produced temperature-oriented geographic gradients for body size in natural populations of several species of Drosophila.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1966

References

REFERENCES

Druger, M. (1962). Selection and body size in Drosophila pseudoobscura at different temperatures. Genetics, 47, 209222.CrossRefGoogle ScholarPubMed
Ehrman, L. (1964). Genetic divergence in M. Vetukhiv's experimental populations of Drosophila pseudoobscura. 1. Rudiments of sexual isolation. Genet. Res. 5, 150157.CrossRefGoogle Scholar
Kalmus, H. (1943). A factorial experiment on the mineral requirements of Drosophila culture. Am. Nat. 77, 376380.CrossRefGoogle Scholar
McFarquhar, A. M. & Robertson, F. W. (1963). The lack of evidence for coadaptation in crosses between geographical races of Drosophila subobscura Coll. Genet. Res. 4, 104131.CrossRefGoogle Scholar
Misra, R. K. & Reeve, E. C. R. (1964). Clines in body dimensions in populations of Drosophila subobscura. Genet. Res. 5, 240256.CrossRefGoogle Scholar
Mourad, A. (1965). Genetic divergence in M. Vetukhiv's experimental populations of Drosophila pseudoobscura. 2. Longevity. Genet. Res. 6, 139146.CrossRefGoogle Scholar
Prevosti, A. (1955). Geographical variability in quantitative traits in populations of Drosophila subobscura. Cold Spring Harb. Symp. quant. Biol. 20, 294299.CrossRefGoogle ScholarPubMed
Ray, C. (1960). The application of Bergmann's and Allen's rules to the poikilotherms. J. Morph. 106, 85108.CrossRefGoogle Scholar
Sokoloff, A. (1965). Geographic variation of quantitative characters in populations of Drosophila pseudoobscura. Evolution, Lancaster, Pa. 19, 300310.CrossRefGoogle Scholar
Spassky, B. (1943). Cream of wheat-molasses fly medium. Drosoph. Inf. Serv. 17, 6768.Google Scholar
Stalker, H. & Carson, H. (1947). Morphological variation in natural populations of Drosophila robusta Sturtevant. Evolution, Lancaster, Pa. 1, 237248.Google Scholar
Stalker, H. & Carson, H. (1948). An altitudinal transect of Drosophila robusta Sturtevant. Evolution, Lancaster, Pa. 2, 295305.CrossRefGoogle Scholar
Waddington, C. H. (1953). Genetic assimilation of an acquired character. Evolution, Lancaster, Pa. 7, 118126.CrossRefGoogle Scholar
Waddington, C. H. (1961). Genetic assimilation. Adv. Genet. 10, 257293.CrossRefGoogle ScholarPubMed
Wright, S. & Dobzhansky, Th. (1946). Genetics of natural populations. XII. Experimental reproduction of some of the changes caused by natural selection in certain populations of Drosophila pseudoobscura. Genetics, 31, 125156.CrossRefGoogle Scholar