Abstract:
:Sex is thought to facilitate accumulation of initially rare beneficial mutations by allowing simultaneous allele replacements at many loci. However, this advantage of sex depends on a restrictive assumption that the fitness of a genotype is determined by fitness potential, a single intermediate variable to which all loci contribute additively, so that new alleles can accumulate in any order. Individual-based simulations of sexual and asexual populations reveal that under generic selection, sex often retards adaptive evolution. When new alleles are beneficial only if they accumulate in a prescribed order, a sexual population may evolve two or more times slower than an asexual population because only asexual reproduction allows some overlap of successive allele replacements. Many other fitness surfaces lead to an even greater disadvantage of sex. Thus, either sex exists in spite of its impact on the rate of adaptive allele replacements, or natural fitness surfaces have rather specific properties, at least at the scale of intrapopulation genetic variability.
journal_name
Proc Natl Acad Sci U S Aauthors
Kondrashov FA,Kondrashov ASdoi
10.1073/pnas.211214298keywords:
subject
Has Abstractpub_date
2001-10-09 00:00:00pages
12089-92issue
21eissn
0027-8424issn
1091-6490pii
211214298journal_volume
98pub_type
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