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The effects of inbreeding and artificial selection on reproductive fitness

Published online by Cambridge University Press:  14 April 2009

B. D. H. Latter  and
Alan Robertson
B. D. H. Latter
Affiliation:
Institute of Animal Genetics, Edinburgh
Alan Robertson
Affiliation:
Institute of Animal Genetics, Edinburgh

Extract

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The competitive-index method of measurement of over all fitness in Drosophila has been used to measure the effect of inbreeding and of artificial selection for metric characters in a large population of Drosophila melanogaster. The technique itself was examined in detail with particular reference to its repeatability and to the effect on it of the modification of various environmental variables.

With continued full-sib mating the decline in the competitive index was very rapid (it was reduced to a half by a single generation of full-sib mating) and there were no indications that interactions between deleterious genes at different loci were important in determining the rate of decline of fitness as inbreeding increased. Other unselected lines with ten pairs of parents in each generation were carried to serve as a control for the lines under artificial selection. At the same theoretical degree of inbreeding the control lines had a much higher average fitness than the lines produced by continued full-sib mating.

From the base population lines were selected in both directions for abdominal bristles, sternopleural bristles and for wing length, there being two replicates in all cases. Four control lines were kept with the same number of parents as the selected lines. In all cases the selected lines declined in fitness below the value for the base population. However, in three of the lines the fitness was not significantly below the value for the control lines. The effect of artificial selection on fitness was asymmetrical, the decline being greater with down selection for all characters.

The relevance of these results to various theoretical models is discussed. If the variation in these characters is actively maintained in the base population by the selection of heterozygotes then the results are consistent with an average selection disadvantage of homozygotes relative to heterozygotes of about 0·5%.

Type
Research Article
Information
Genetics Research , Volume 3 , Issue 1 , February 1962 , pp. 110 - 138
Copyright
Copyright © Cambridge University Press 1962

References

REFERENCES

Bell, A. E., Moore, C. H. & Warren, D. C. (1955). The evaluation of new methods for the improvement of quantitative characteristics. Cold Spr. Harb. Symp. quant. Biol. 20, 197–212.CrossRefGoogle ScholarPubMed
Clayton, G. A., Morris, J. A. & Robertson, A. (1957 a). An experimental check on quantitative genetical theory. I. Short-term responses to selection. J. Genet. 55, 131–151.CrossRefGoogle Scholar
Clayton, G. A. & Robertson, A. (1957 b). An experimental check on quantitative genetical theory. II. The long-term effects of selection. J. Genet. 55, 152–170.CrossRefGoogle Scholar
Clayton, G. A., Knight, G. R., Morris, J. A. & Robertson, A. (1957 c). An experimental check on quantitative genetical theory. III. Correlated responses. J. Genet. 55, 171–180.CrossRefGoogle Scholar
Crow, J. F. (1948). Alternative hypotheses of hybrid vigour. Genetics, 33, 477–487.CrossRefGoogle Scholar
Crow, J. F. (1954). Breeding structure of populations. II. Effective population number. Statistics and Mathematics in Biology. Iowa State College Press.Google Scholar
Dickerson, G. E., Blum, C. T., Chapman, A. B., Kottman, R. M., Krider, J. L., Warwick, E. J. & Whatley, J. A. Jr (1954). Evaluation of selection in developing inbred lines of swine. Univ. Mo. Res. Bull. 551.Google Scholar
Falconer, D. S. (1954). Validity of the theory of genetic correlation. J. Hered. 45, 42–44.CrossRefGoogle Scholar
Gowen, J. W. & Johnson, L. E. (1946). On the mechanism of heterosis. I. Metabolic capacity of different races of Drosophila melanogaster for egg production. Amer. Nat. 80, 149–179.CrossRefGoogle ScholarPubMed
Haldane, J. B. S. (1954). The measurement of natural selection. Proc. IXth Int. Congr. Genet. 1, 480–487.Google Scholar
Hull, F. H. (1952). Recurrent selection and overdominance. In Heterosis (Gowen, J. W., ed.). Iowa State College Press.Google Scholar
Kempthorne, O. (1957). An Introduction to Genetic Statistics. New York: Wiley and Sons.Google Scholar
Knight, G. R. & Robertson, A. (1957). Fitness as a measurable character in Drosophila. Genetics, 42, 524–530.CrossRefGoogle ScholarPubMed
Kyle, W. H. & Chapman, A. B. (1953). Experimental check of the effectiveness of selection for a quantitative character. Genetics, 38, 421–443.CrossRefGoogle ScholarPubMed
Latter, B. D. H. (1960). Natural selection for an intermediate optimum. Aust. J. biol. Sci. 13, 30–35.CrossRefGoogle Scholar
Latter, B. D. H. (1961). Changes in reproductive fitness under artificial selection. Proc. roy. Soc. Vict. Centenary Symposium (in press).Google Scholar
Lerner, I. M. (1954). Genetic Homeostasis. Edinburgh: Oliver and Boyd.Google Scholar
Lerner, I. M. (1958). The Genetic Basis of Selection. New York: Wiley and Sons.Google Scholar
Lewontin, R. C. (1955). The effects of population density and composition on viability in Drosophila melanogaster. Evolution, 9, 27–41.CrossRefGoogle Scholar
Mather, K. & Harrison, B. J. (1949). The manifold effect of selection. Heredity, 3, 1–52, 131–162.CrossRefGoogle ScholarPubMed
Maynard Smith, J., Clarke, J. M. & Hollingsworth, M. J. (1955). The expression of hybrid vigour in Drosophila subobscura. Proc. roy. Soc. B, 144, 159–171.Google Scholar
Reeve, E. C. R. & Robertson, F. W. (1953). Studies in quantitative inheritance. II. Analysis of a strain of Drosophila melanogaster selected for long wings. J. Genet. 51, 276–316.CrossRefGoogle Scholar
Robertson, A. (1952). The effect of inbreeding on the variation due to recessive genes. Genetics, 37, 189–207.CrossRefGoogle ScholarPubMed
Robertson, A. (1960). A theory of limits in artificial selection. Proc. roy. Soc. B, 153, 234–249.Google Scholar
Robertson, A. (1961). Inbreeding in artificial selection programmes. Genet. Res. 2, 189–194.CrossRefGoogle Scholar
Robertson, F. W. (1955). Selection response and the properties of genetic variation. Cold Spr. Harb. Symp. quant. Biol. 20, 166–177.CrossRefGoogle ScholarPubMed
Robertson, F. W. (1957). Studies in quantitative inheritance. XI. Genetic and environmental correlation between body size and egg production in Drosophila melanogaster. J. Genet. 55, 428–443.CrossRefGoogle Scholar
Robertson, F. W. & Reeve, E. C. R. (1952). Studies in quantitative inheritance. I. The effects of selection on wing and thorax length in Drosophila melanogaster. J. Genet. 50, 414–448.CrossRefGoogle Scholar
Robertson, F. W. & Reeve, E. C. R. (1955). Studies in quantitative inheritance. VIII. Further analysis of heterosis in crosses between inbred lines of Drosophila melanogaster. Z. indukt. Abstamm.-u. VererbLehre, 86, 439–458.Google ScholarPubMed
Sentz, J. C, Robinson, H. F. & Comstock, R. E. (1954). Relation between heterozygosis and performance in maize. Agron. Hourn. 46, 514–520.CrossRefGoogle Scholar
Tantawy, A. O. (1957). Genetic variance of random-inbred lines of Drosophila melanogaster in relation to coefficients of inbreeding. Genetics, 42, 121–136.CrossRefGoogle ScholarPubMed
Tantawy, A. O. & Reeve, E. C. R. (1956). Studies in quantitative inheritance. IX. The effects of inbreeding at different rates in Drosophila melanogaster. Z. indukt. Abstamm.-u. VererbLehre, 87, 648–667.Google ScholarPubMed
Wigan, L. G. & Mather, K. (1942). Correlated response to the selection of polygenic characters. Ann. Eugen. 11, 354–364.CrossRefGoogle Scholar