SEX REDUCES GENETIC VARIATION: A MULTIDISCIPLINARY REVIEW
Article first published online: 20 NOV 2010
© 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.
Volume 65, Issue 4, pages 1088–1098, April 2011
How to Cite
Gorelick, R. and Heng, H. H. Q. (2011), SEX REDUCES GENETIC VARIATION: A MULTIDISCIPLINARY REVIEW. Evolution, 65: 1088–1098. doi: 10.1111/j.1558-5646.2010.01173.x
- Issue published online: 4 APR 2011
- Article first published online: 20 NOV 2010
- Received August 4, 2010, Accepted September 3, 2010
- evolutionary genomics;
- genetic variation;
- genome theory;
For over a century, the paradigm has been that sex invariably increases genetic variation, despite many renowned biologists asserting that sex decreases most genetic variation. Sex is usually perceived as the source of additive genetic variance that drives eukaryotic evolution vis-à-vis adaptation and Fisher's fundamental theorem. However, evidence for sex decreasing genetic variation appears in ecology, paleontology, population genetics, and cancer biology. The common thread among many of these disciplines is that sex acts like a coarse filter, weeding out major changes, such as chromosomal rearrangements (that are almost always deleterious), but letting minor variation, such as changes at the nucleotide or gene level (that are often neutral), flow through the sexual sieve. Sex acts as a constraint on genomic and epigenetic variation, thereby limiting adaptive evolution. The diverse reasons for sex reducing genetic variation (especially at the genome level) and slowing down evolution may provide a sufficient benefit to offset the famed costs of sex.