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The lack of evidence for co-adaptation in crosses between geographical races of Drosophila subobscura Coll.

Published online by Cambridge University Press:  14 April 2009

A. M. McFarquhar  and
Forbes W. Robertson
A. M. McFarquhar
Affiliation:
Institute of Animal Genetics, Edinburgh, 9
Forbes W. Robertson
Affiliation:
Institute of Animal Genetics, Edinburgh, 9
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1. The paper described an attempt to see whether differences in co-adaptation between populations of Drosophila subobscura are related to the distance between them. The mean and the variance of body-size, development time and survival were recorded on parent populations and the F1 and F2 of various crosses to test for heterosis in the F1 and decline in performance or greater variance in the F2, which might indicate the break-up of co-adapted gene arrays. Comparisons were carried out at different temperatures and on a variety of larval diets, especially sub-optimal ones in which the larvae were grown on synthetic media. A large number of wild flies were caught at sites separated by about 10 miles along a transect of southern Scotland; these comprised one series of comparisons. For more distant crosses flies were caught at sites in southern England, Denmark, Switzerland and Israel.

2. There were well-defined differences in body-size, and, to a lesser degree, development time between populations from more widely separated localities and these showed evidence of a cline, northern populations having larger body-size. The difference in size between the Scottish and Isreal populations is about 20%.

3. There was no evidence of differences in co-adaptation between populations even in crosses between populations from sites as far apart as Scotland and Israel. The F1's were always close to the mid-parent values and there was no evidence of breakdown in the F2 nor of increased variability.

4. There was hardly any evidence of gene-environment interaction either with respect to different diets or to different temperatures.

5. Records of body-size on flies caught in the wild showed that they are extremely variable, indicating great variation in larval nutrition. Under natural condition stability of growth in body-size is conspicuously lacking in this species.

6. An additional test of co-adaptation was based on the between-family variance of abdominal bristle number of intra- and inter-population matings in the two most widely separated populations. There was no evidence of greater variance in the inter-population series.

7. To test for possible differences in breeding structure, the response to inbreeding was determined for two widely separated populations of D. subobscura and a long-established cage population of D. melanogaster, on an unrestricted larval diet and also on several different kinds of sub-optimal diets. There was little or no sign of consistent differences between the species in their response to inbreeding.

8. This test revealed differences between the two species in their minimum requirements for particular nutrients. subobscura is less able than melanogaster to withstand lower levels of protein and survival is particularly reduced. On the other hand, melanogaster has a considerably higher requirement for choline. Where there are apparent differences between the species in the average effect of inbreeding, the inbreeding effect is greater on the relatively more sub-optimal diet.

9. Comparison of the performance of the immediate descendants of wild flies with those derived from the same site, but kept in the laboratory for some twenty generations, failed to show any differences on several different diets and so there was no evidence that adaptation to laboratory conditions was important.

10. The lack of evidence for co-adaptation apparently conflicts with what has been claimed for other species. Such differences are discussed.

Type
Research Article
Information
Genetics Research , Volume 4 , Issue 1 , February 1963 , pp. 104 - 131
Copyright
Copyright © Cambridge University Press 1963

References

REFERENCES

Basden, E. B. (1954). The distribution and biology of Drosophilidae (Diptera) in Scotland, including a new species of Drosophila. Trans. roy. Soc. Edinb. 62, 603.CrossRefGoogle Scholar
Breese, E. L. & Mather, K. (1960). The organisation of polygenic activity within a chromosome in Drosophila. Heredity, 14, 375.CrossRefGoogle Scholar
Brncic, D. (1954). Heterosis and the integration of the genotype in geographical populations of Drosophila pseudoobscura. Genetics, 39, 77.CrossRefGoogle ScholarPubMed
Clarke, J. M., Maynard Smith, J. & Sondhi, K. C. (1961). Asymmetrical response to selection for rate of development in Drosophila subobscura. Genet. Res.. 2, 70–81.CrossRefGoogle Scholar
Dobzhansky, Th. (1949). Observation and experiments on natural selection in Drosophila. Hereditas, Lund., suppl. vol.Google Scholar
Dobzhansky, Th. (1950). Genetics of natural populations. XIX. Origin of heterosis through natural selection in populations of Drosophila pseudoobscura. Genetics, 35, 288–302.CrossRefGoogle ScholarPubMed
Dobzhansky, Th. (1954). Evolution as a creative process. Caryologia, Vol. 6 Suppl., 435–449.Google Scholar
Dobzhansky, Th., Burla, H. & Da Cunha, A. B. (1950). A comparative study of chromosomal polymorphism in sibling species of the willistoni group of Drosophila. Amer. Nat. 84, 229.Google Scholar
Goldschmidt, E. (1956). Chromosomal polymorphism in Drosophila subobscura. J. Genet. 54, 474.CrossRefGoogle Scholar
Haldane, J. B. S. (1959). Natural Selection in ‘Darwin's Biological Work’, Cambridge University Press, pp. 101–149.Google Scholar
Knight, G. R. (1961). Structural polymorphism in Drosophila subobscura. Coll. from various localities in Scotland. Genet. Res.. 2, 1–9.CrossRefGoogle Scholar
Mather, K. (1943). Polygenic inheritance and natural selection. Biol. Rev. 18, 32.CrossRefGoogle Scholar
Maynard Smith, J., Clarke, J. M. & Hollingsworth, M. J. (1955). The expression of hybrid vigour in Drosophila subobscura. Proc. roy. Soc. B., 144, 159.Google Scholar
Mayr, E, (1959). Where are we? Cold. Spr. Harb. Symp. quant. Biol. 24.CrossRefGoogle Scholar
Prabhu, S. S., & Robertson, F. W. (1961). The ecological genetics of growth in Drosophila V. (Gene-environment interaction and inbreeding.) Genet. Res.. 2, 424–430.CrossRefGoogle Scholar
Prevosti, A. (1955). Geographical variability in quantitative traits in populations of Drosophila subobscura. Cold Spr. Harb. Symph. quant. biol. 20, 294.CrossRefGoogle ScholarPubMed
Prevosti, A. (1957). Viabilidad en Cruces entre poblaciones de Drosophila subobscura de distinta procedencia geografica. Publ. Inst. Biol. apl. Bacelona, 26, 53.Google Scholar
Robertson, F. W. (1954). Studies in quantitative inheritance. V. Chromosome analyses of crosses between selected and unselected lines of different body size in Drosophila melanogaster. J. Genet. 52, 494–515.CrossRefGoogle Scholar
Robertson, F. W. (1959 a). Studies in quantitative inheritance. XII. Cell size and number in relation to genetic and environmental variation of body size in Drosophila. Genetics, 44, 1113–1130.CrossRefGoogle ScholarPubMed
Robertson, F. W. (1961 b). The ecological genetics of growth in Drosophila. IV. The influence of larval nutrition on the manifestation of dominance. Genet. Res.. 2, 346–360.CrossRefGoogle Scholar
Sang, J. H. (1956). The quantitative nutritional requirements of Drosophila melanogaster. J. exp. Biol. 33, 45.CrossRefGoogle Scholar
Sang, J. H. & Clayton, G. A. (1957). Selection for larval development time in Drosophila. J. Hered. 48, 265.CrossRefGoogle Scholar
Sokoloff, (1957). Discussion after paper by A. Milne: ‘Theories of natural control of insect populations’. Cold Spr. Harb. Symp. quant. Biol., 22, 268–271.Google Scholar
Spassky, B., Spassky, N., Pavlovsky, O., Krimbas, M. G., Krimbas, C. & Dobzhansky, T. (1960). Genetics of natural populations. XXIX. The magnitude of the genetic load in populations of Drosophila pseudoobscura. Genetics, 45, No. 6, 723–740.CrossRefGoogle Scholar
Spiess, E. (1950). Experimental population of Drosophila persimilis from an altitudinal transect of the Sierra Nevada. Evolution, 4, 14–33.Google Scholar
Vetukhiv, M. (1954). Integration of the genotype in local populations of three species of Drosophila. Evolution, 8, 241.CrossRefGoogle Scholar
Vetukhiv, M. (1956). Fecundity of hybrids between grographic populations of Drosophila pseudo-obscura. Evolution, 10, 139.CrossRefGoogle Scholar
Vetukhiv, M. (1957). Longevity of hybrids between geographic populations of Drosophila pseudo-obscura. Evolution, 11, 348.CrossRefGoogle Scholar
Wallace, B. (1953). On co-adaptation in Drosophila. Amer. Nat. 87, 343.CrossRefGoogle Scholar
Wallace, B. (1955). Inter population hybrids in Drosophila melanogaster. Evolution, 9, 302.CrossRefGoogle Scholar
Wright, S. (1931). Evolution in Mendelian populations. Genetics, 16, 97–159.CrossRefGoogle ScholarPubMed