Sex

Sex

Adaptation to uncertain environments

Adaptation to Uncertain environments

Tangled Bank: Heterogeneous environment

The Tangled Bank holds that the state of the environment varies widely from place to place on a very local scale, such that different genotypes are optimal at different sites. Since each site can support only a few individuals, the uniform progeny of an asexual female will compete intensely with one another for the same set of resources, while the progeny of a sexual female, which by virtue of their diversity will be able to exploit a much wider range of sites, will compete amongst themselves less intensely and thus achieve greater overall success.

Sib-competition (Maynard Smith)

Density-dependent competition between siblings is wasteful from the point of view of the parent, and that this competition becomes more intense as siblings become genetically more similar.

Red-Queen: Temporal

It attributes the success of sexuality to the continual necessity to respond to the shifting challenge of antagonists such as predators and parasites.

Benefits of Recombination

Muller’s Rachet

Hill-Robertson effect

Linkage between sites under selection will reduce the overall effectiveness of selection in finite populations.