Evolution in Sexual and Asexual Populations

  title={Evolution in Sexual and Asexual Populations},
  author={James F. Crow and Motoo Kimura},
  journal={The American Naturalist},
  pages={439 - 450}
In an asexual population two favorable mutants can be incorporated into the population only if one occurs in a descendant of the individual in which the other occurred. In a sexual population both mutants can be incorporated through recombination. A mathematical formulation is given of the relative rates of incorporation of the new mutations with and without recombination. Recombination is of the greatest advantage when the double mutant is more advantageous than either single mutant, when the… 
Rate of Adaptation in Large Sexual Populations
The rate of adaptation, v, is calculated in several models of such sexual populations and it is shown that v is linear in NUb only in sufficiently small populations, and acceleration of adaptation by recombination implies a strong evolutionary advantage of sex.
Evolution in Sexual and Asexual Populations
In a simple model case, the rates of evolution in an asexual and a sexual haploid population are compared. It is shown that, if the genetic variance of the population is generated by mutation in a
The advantages of segregation and the evolution of sex.
This article is the first to investigate the possibility that sex might have evolved and been maintained to promote segregation, using a model that incorporates both a general selection regime and modifier alleles that alter an individual's allocation to sexual vs. asexual reproduction.
Haploidy or diploidy: which is better?
The efficiency of elimination of deleterious mutations as an evolutionary force is considered and the mutation loads under haploid and diploid selection, Ln and L2n are compared to suggest that the mutation rate, degree of dominance and mode of selection can be important in life-cycle evolution.
In a population of constant size the expected heterozygosity for a neutral locus when mutation and genetic drift are balanced is given by 4 Nv/(4Nv + 1) under the assumption that new mutations are
The fate of competing beneficial mutations in an asexual population
The beneficial mutation rate and the distribution of mutational effects from changes in mean fitness in an evolving E. coli population are estimated.
Evolution in Sexual and Asexual Populations: A Reply
The main point of Muller's papers, and the one on which it was elaborated, is the value of recombination in putting together rare advantageous genes that occur in separate individuals, and there is exactly the same rate of change with recombination as without it.
Does Diploidy Increase the Rate of Adaptation ?
It is shown that, in both asexuals and sexuals, doubling the mutation rate via diploidy often does not accelerate the rate of adaptation, and a neglected alternative theory which posits that, by doubling the genome size, diploids double the rate at which favorable mutations arise is explored.
Mating systems and the evolutionary transition between haploidy and diploidy
It is suggested that a correlation should exist between mating system and ploidy level, with outcrossing favouring diploid life cycles and inbreeding or asexual reproduction favouring haploids life cycles.


The Effect of Variation of Fitness
In a species in equilibrium variation, some deleterious genes are being weeded out by selection at the same rate as they are produced by mutation and the loss of fitness in the species is roughly equal to the sum of all mutation rates.
Some Genetic Aspects of Sex
FPROM the genetic point of view it is advantageous to begin by considering sex in the broader sense of sexuality. It is not generally realized that genetics has finally solved the age-old problem of
The Genetical Theory of Natural Selection
Although it is true that most text-books of genetics open with a chapter on biometry, closer inspection will reveal that this has little connexion with the body of the work, and that more often than not it is merely belated homage to a once fashionable study.
Physiological Genetics, Ecology of Populations, and Natural Selection
  • S. Wright
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Polygenic inheritance of drugresistance in the
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