Multidimensional epistasis and the transitory advantage of sex

PLoS Comput Biol. 2014 Sep 18;10(9):e1003836. doi: 10.1371/journal.pcbi.1003836. eCollection 2014 Sep.

Abstract

Identifying and quantifying the benefits of sex and recombination is a long-standing problem in evolutionary theory. In particular, contradictory claims have been made about the existence of a benefit of recombination on high dimensional fitness landscapes in the presence of sign epistasis. Here we present a comparative numerical study of sexual and asexual evolutionary dynamics of haploids on tunably rugged model landscapes under strong selection, paying special attention to the temporal development of the evolutionary advantage of recombination and the link between population diversity and the rate of adaptation. We show that the adaptive advantage of recombination on static rugged landscapes is strictly transitory. At early times, an advantage of recombination arises through the possibility to combine individually occurring beneficial mutations, but this effect is reversed at longer times by the much more efficient trapping of recombining populations at local fitness peaks. These findings are explained by means of well-established results for a setup with only two loci. In accordance with the Red Queen hypothesis the transitory advantage can be prolonged indefinitely in fluctuating environments, and it is maximal when the environment fluctuates on the same time scale on which trapping at local optima typically occurs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Computational Biology
  • Epistasis, Genetic / genetics*
  • Evolution, Molecular
  • Models, Genetic*
  • Recombination, Genetic / genetics*
  • Reproductive Physiological Phenomena / genetics*
  • Selection, Genetic / genetics

Grants and funding

This work was funded by Deutsche Forschungsgemeinschaft (http://www.dfg.de/) through the Bonn Cologne Graduate School for Physics and Astronomy and through grants SFB 680, SFB TR12 and SPP 1590. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.