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Error thresholds and stationary mutant distributions in multi-locus diploid genetics models

Published online by Cambridge University Press:  14 April 2009

Paul G. Higgs
Affiliation:
University of Sheffield, Department of Physics, Hounsfield Road, Sheffield S3 7RH, U.K.
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We study multi-locus models for the accumulation of disadvantagenous mutant alleles in diploid populations. The theory used is closely related to the quasi-species theory of molecular evolution. The stationary mutant distribution may either be localized close to a peak in the fitness landscape or delocalized throughout sequence space. In some cases there is a sharp transition between these two cases known as an error threshold. We study a multiplicative fitness landscape where the fitness of an individual with j homozygous mutant loci and k heterozygous loci is wjk = (1 − s)j (1 − hs)k. For a sexual population in this landscape there are two types of solution separated by an error threshold. For a parthenogenetic population there may be three types of solution and two error thresholds for some values of h. For a population reproducing by selfing the solution is independent of h, since the frequency of heterozygous individuals is negligible. The mean fitnesses of the populations depend on the reproductive method even for the multiplicative landscape. The sexual may have a higher or lower fitness than the parthenogen, depending on the values of h and u/s. Selfing leads to a higher mean fitness than either sexual reproduction or parthenogenesis. We also study a fitness landscape with epistatic interactions with wjk = exp(− s(2j + k)α). The sexual population has a higher fitness than the parthenogen when α > 1. This confirms previous theories that sexual reproduction is advantageous in cases of synergistic epistasis. The mean fitness of a selfing population was found to be higher than both the sexual and the parthenogen over the range of parameter values studied. We discuss these results in relation to the theory of the evolution of sex. The fitness of the stationary distribution in cases where unfavourable mutations accumulation is one factor which could explain the observed prevalence of sexual reproduction in natural populations, although other factors may be more important in many cases.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1994

References

Barton, N. H. & Rouhani, S. (1987). The frequency of shifts between alternative equilibria. Journal of Theoretical Biology 125, 397418.CrossRefGoogle ScholarPubMed
Bonhoeffer, S., McCaskill, J. S., Stadler, P. F. & Schuster, P. (1993). RNA multi-structure landscapes. European Biophysical Journal 22, 1324.CrossRefGoogle ScholarPubMed
Charlesworth, B. (1990). Mutation-selection balance and the evolutionary advantage of sex and recombination. Genetical Research 55, 199221.CrossRefGoogle ScholarPubMed
Charlesworth, D., Morgan, M. T. & Charlesworth, B. (1992). The effect of linkage and population size on inbreeding depression due to mutational load. Genetical Research 59, 4961.CrossRefGoogle ScholarPubMed
Charlesworth, D., Morgan, M. T. & Charlesworth, B. (1993). Mutation accumulation in finite outbreeding and inbreeding populations. Genetical Research 61, 3956.CrossRefGoogle Scholar
Crow, J. F. & Kimura, M. (1970). An Introduction to Population Genetics Theory. New York: Harper and Row.Google Scholar
Derrida, B. & Peliti, L. (1991). Evolution in a flat fitness landscape. Bulletin of Mathematical Biology 53, 355382.CrossRefGoogle Scholar
Donnelly, P. & Tavaré, S. (1987). The population genealogy of the infinitely many neutral alleles model. Journal of Mathematical Biology 25, 381391.CrossRefGoogle ScholarPubMed
Eigen, M., McCaskill, J. & Schuster, P. (1989). The molecular quasi-species. Advances in Chemical Physics 75, 149263.Google Scholar
Also in abridged form in Journal of Physical Chemistry (1988) 92, 68816891.CrossRefGoogle Scholar
Fontana, W., Schnabl, W. & Schuster, P. (1989). Physical aspects of evolutionary optimization and adaptation. Physical Review A. 40, 33013321.CrossRefGoogle ScholarPubMed
Fontana, W., Stadler, P. F., Bornberg-Bauer, E. G., Gries-macher, T., Hofacker, I. L., Tacker, M., Tarazona, P., Weinberger, E. D. & Schuster, P. (1993). RNA folding and combinatory landscapes. Physical Review E 47, 2083–99.CrossRefGoogle ScholarPubMed
Gillespie, J. H. (1991). The causes of Molecular Evolution. Oxford University Press.Google Scholar
Haigh, J. (1978). The accumulation of deleterious genes in a population - Muller's Ratchet. Theoretical Population Biology 14, 251267.CrossRefGoogle Scholar
Hamilton, W. D., Axelrod, R. & Tanese, R. (1990). Sexual reproduction as an adaptation to resist parasites. Proceedings of the National Academy of Sciences (USA) 87, 35663569.CrossRefGoogle ScholarPubMed
Higgs, P. G. (1993). RNA secondary structure: a comparison of real and random sequences. Journal de Physique (France) 13, 4359.Google Scholar
Higgs, P. G. & Derrida, B. (1991). Stochastic models for species formation in evolving populations. Journal of Physics A (Mathematical and General) 24, L985–L991.CrossRefGoogle Scholar
Higgs, P. G. & Derrida, B. (1992). Genetic distance and species formation in evolving populations. Journal of Molecular Evolution 35, 454465.CrossRefGoogle ScholarPubMed
Houle, D., Hoffmaster, D. K., Assimacopoulos, S. & Charlesworth, B. (1992). The genomic mutation rate for fitness in Drosophila. Nature 359, 5860.CrossRefGoogle ScholarPubMed
Huynen, M. A. & Hogeweg, P. (1993). Evolutionary dynamics and the relationship between RNA structure and RNA landscapes. Proceedings of the European Conference on Artificial Life, Brussels, May 1993.Google Scholar
Kimura, M. (1983). The Neutral Theory of Molecular Evolution. Cambridge University Press.CrossRefGoogle Scholar
Kimura, M. & Maruyama, T. (1966). The mutational load with epistatic gene interactions in fitness. Genetics 54, 13371351.CrossRefGoogle ScholarPubMed
Kondrashov, A. S. (1982). Selection against harmful mutations in large sexual and asexual populations. Genetical Research 40, 325332.CrossRefGoogle ScholarPubMed
Kondrashov, A. S. (1984). Deleterious mutations as an evolutionary factor. I. The advantage of recombination. Genetical Research 44, 199217.CrossRefGoogle Scholar
Kondrashov, A. S. (1985). Deleterious mutations as an evolutionary factor. II. Facultative apomixis and selling Genetics 111, 635653.Google ScholarPubMed
Kondrashov, A. S. (1988). Deleterious mutations and the evolution of sexual reproduction. Nature 336, 435440.CrossRefGoogle ScholarPubMed
Kondrashov, A. S. & Crow, J. F. (1991). Haploidy or diploidy: which is better? Nature 351, 314–5.CrossRefGoogle ScholarPubMed
Leuthäuser, I. (1986). An exact correspondence between Eigen's evolution model and a two dimensional Ising system. Journal of Chemical Physics 84, 18841885.CrossRefGoogle Scholar
Lewis, W. M. Jr. (1987). The costs of sex. In The Evolution of Sex and its Consequences, (ed. Stearns, S. C.). Basel: Birkhäuser Verlag.Google Scholar
Maynard Smith, J. (1978). The Evolution of Sex. Cambridge University Press.Google Scholar
Nowak, M. & Schuster, P. (1989). Error thresholds of replication in finite populations, mutation frequencies, and the onset of Muller's ratchet. Journal of Theoretical Biology 137, 375395.CrossRefGoogle ScholarPubMed
Perelson, A. S. & Kauffman, S. A. (Eds.) (1991). Molecular evolution on rugged landscapes: Proteins, RNA, and the immune system. (Santa Fe Institute). Addison-Wesley, California.Google Scholar
Stearns, S. C. (1987). Why sex evolved and the difference it makes. In The Evolution of Sex audits Consequences, (ed. Stearns, S. C.). Basel: Birkhäuser Verlag.CrossRefGoogle Scholar
Stephan, W., Chao, L. & Smale, J. G. (1993). The advance of Muller's ratchet in a haploid asexual population: approximate solutions based on diffusion theory. Genetical Research 61, 225231.CrossRefGoogle Scholar
Swetina, J. & Schuster, P. (1982). Self-replication with errors-A model for polynucleotide replication. Biophysical Chemistry 16, 329345.CrossRefGoogle ScholarPubMed
Tarazona, P. (1992). Error thresholds for molecular quasi-species as phase transitions: From simple landscapes to spin-glass models. Physical Review A. 45, 60386050.CrossRefGoogle ScholarPubMed
Wright, S. (1969). Evolution and the Genetics of Populations (Vol. 2) University of Chicago Press.Google Scholar