Conveners
Pleiotropy, adaptation and the evolution of sex differences
- Tim Connallon ()
Description
Pleiotropy refers to the fact that each genetic variant may affect the expression of multiple traits. This widespread feature of genetic variation is central to the capacity of each trait and type of individual within a population to vary and evolve independently of others, and carries with it broad biological implications. For example, pleiotropy directly impacts the genetic basis of variation among traits, classes of individuals, and population fitness. Pleiotropy potentially generates strong biases in the direction of evolutionary change over time, and across species’ geographic ranges in space. Pleiotropy may also mediate the likelihood of extinction versus population persistence, and may act as either a constraint or facilitator of rapid adaptation in populations exposed to changing environmental conditions.
There is a rich tradition of mathematical models in evolutionary biology that explore consequences of pleiotropy for adaptation and the maintenance and structure of population and quantitative genetic variation. More recent research trends in the field have seen an increased application of classical theories of pleiotropy to modern – and often massive – genomic and quantitative genetic datasets. Another trend is the extension of classical evolutionary models of pleiotropy to various aspects of sex differences, including the potential for adaptive differentiation between sexes, and the manifestation of sex differences in genetic variation and disease.
A gene is imprinted when its level of expression is dependent on the sex of the parent it was inherited from. An unusual consequence of imprinting is that male and female additive genetic variances differ, and so ignoring imprinting can lead to misspecification of a number of evolutionary parameters, including the predicted response to selection. QST - the differentiation of quantitative...
Arguments about the evolutionary modification of genetic dominance have a long history in genetics, dating back over 100 years. Mathematical investigations have shown that modifiers of the level of dominance at the locus of interest can only spread at a reasonable rate if heterozygotes at that locus are common. One hitherto neglected scenario is that of sexually antagonistic selection, which...
Organisms often modify their environments to their advantage through a process of niche construction. Environments that are improved through positive niche construction can be viewed as a public good. If free riders appear that do not contribute to the shared resource and therefore do not incur any associated costs, the constructed niche may become degraded resulting in a tragedy of the...
Strict maternal inheritance renders the mitochondrial genome susceptible to accumulating mutations that harm males, but are otherwise benign or beneficial for females. This ‘mother's curse’ effect can degrade male survival and fertility if unopposed by counteracting evolutionary processes. Coadaptation between nuclear and mitochondrial genomes—with nuclear genes evolving to compensate for...
