The Evolutionary Enigma of Sex

@article{Otto2009TheEE,
  title={The Evolutionary Enigma of Sex},
  author={Sarah Perin Otto},
  journal={The American Naturalist},
  year={2009},
  volume={174},
  pages={S1 - S14}
}
  • S. Otto
  • Published 1 July 2009
  • Psychology
  • The American Naturalist
Sexual reproduction entails a number of costs, and yet the majority of eukaryotes engage in sex, at least occasionally. In this article, I review early models to explain the evolution of sex and why they failed to do so. More recent efforts have attempted to account for the complexities of evolution in the real world, with selection that varies over time and space, with differences among individuals in the tendency to reproduce sexually, and with populations that are limited in size. These… 
Sex : Advantage
TLDR
One of the most important unanswered questions in evolutionary biology is why sexual reproduction is so common, and it is likely that part of the answer is linked to an advantage of sex under pressure from coevolving parasites.
Current hypotheses for the evolution of sex and recombination.
TLDR
Current theoretical and experimental evidence seems to favor the hypothesis that sex breaks down selection interference between new mutants, or it acts as a mechanism to shuffle genotypes in order to repel parasitic invasion, however, there is still a need to collect more data from natural populations and experimental studies, which can be used to test different hypotheses.
Structured Populations and the Maintenance of Sex
TLDR
The role of spatial structure in supporting sexual populations is examined and a simpler, more plausible model is developed that demonstrates the role of mutation, local competition and dispersal in maintaining sexual populations.
Using Parthenogenetic Lineages to Identify Advantages of Sex
TLDR
It is argued that general insights into the advantages of sex can be generated by taking advantage of parthenogenetic taxa that differ in such characteristics as meiotic versus mitotic offspring production, ploidy level, and single versus multiple and hybrid versus non-hybrid origin.
Lineage Selection and the Maintenance of Sex
TLDR
The view that the long-term advantages of sex and lineage selection may provide the most satisfactory explanations for the maintenance of sex in eukaryotes is reinforced, and the mechanisms underlying the higher extinction rates of asexual lineages than of their sexual counterparts are simulated.
Evolution of sex: Using experimental genomics to select among competing theories
  • N. P. Sharp, S. Otto
  • Biology, Psychology
    BioEssays : news and reviews in molecular, cellular and developmental biology
  • 2016
TLDR
The insights provided by the study recently demonstrated that sex uncouples beneficial and deleterious mutations, allowing selection to proceed more effectively with sex than without are discussed in the context of the major theoretical models for the evolution of sex.
The Costs Of Sex: Facing Real-world Complexities
TLDR
It is suggested that, in some species, no general benefits to sex and recombination might be needed to understand the maintenance of sex, as in the case study of dandelions.
The many costs of sex.
The Queen of Problems in Evolutionary Biology
TLDR
Experimental evolution studies show that outcrossing can speed up the response to selection, while studies on natural populations emphasise the importance of niche differentiation and parasites.
Sex and the origin of genetic exchanges
TLDR
To understand why sex has evolved, it is necessary to answer two crucial questions: i) what are the key differences between eukaryotes and bacteria and ii) why do some eucaryotes use asexual reproduction.
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 111 REFERENCES
The Evolution of Condition-Dependent Sex in the Face of High Costs
TLDR
It is shown that alleles promoting individuals of low fitness to have sex more often than individuals of high fitness spread through a population are more likely to segregate out of bad genetic backgrounds and onto good genetic backgrounds, where they tend to remain.
The evolution of sex: empirical insights into the roles of epistasis and drift
TLDR
New ideas about the evolution of sexual recombination are being tested, including intriguing suggestions of an important interplay between sex and genetic architecture, which indicate that sex and recombination could have affected their own evolution.
Species Interactions and the Evolution of Sex
TLDR
A population genetics model is developed that circumscribes a broad array of ecological and genetic interactions among species and derives the first general analytical conditions for the impact of species interactions on the evolution of sex.
Sexual reproduction as an adaptation to resist parasites (a review).
TLDR
P parasite coevolution is superior to previous models of the evolution of sex by supporting the stability of sex under the following challenging conditions: very low fecundity, realistic patterns of genotype fitness and changing environment, and frequent mutation to parthenogenesis, even while sex pays the full 2-fold cost.
Sex releases the speed limit on evolution
TLDR
It is shown that sex can increase the rate of adaptation in the facultatively sexual single-celled chlorophyte Chlamydomonas reinhardtii, but that the benefits of sex depend crucially on the size of the population that is adapting: sex has a marked effect in large populations but little effect in small populations.
Sex increases the efficacy of natural selection in experimental yeast populations
TLDR
It is shown that, as predicted by the theory, sex increases the rate of adaptation to a new harsh environment but has no measurable effect on fitness in a new benign environment where there is little selection.
Why have sex? The population genetics of sex and recombination.
TLDR
Various hypotheses for why sex and recombination are so prevalent are reviewed and theoretical results indicating which of these hypotheses is most promising are discussed.
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
An hypothesis to account for the maintenance of sex within populations
TLDR
Two approaches to the problem of the evol-utionary signlficance of sexual reproduct ion have been taken and it is pointed out that rates of recombinat,ion, which is somewhat analogous to sex, are varl-able and selectable in naturalpopulat{ons.
Benefits and handicaps of sexual reproduction.
TLDR
According to theories of regulation of recombination systems, a wide array of structural and ecological features of organisms, including sexuality vs. asexuality, are adjusted together to produce a supposedly optimal supply of genetic recombinants.
...
1
2
3
4
5
...