title: Environment-dependent variation in selection on life history across small spatial scales.
abstract: Variation in life-history traits is ubiquitous, even though genetic variation is thought to be depleted by selection. One potential mechanism for the maintenance of trait variation is spatially variable selection. We explored spatial variation in selection in the field for a colonial marine invertebrate that shows phenotypic differences across a depth gradient of only 3 m. Our analysis included life-history traits relating to module size, colony growth, and phenology. Directional selection on colony growth varied in strength across depths, while module size was under directional selection at one depth but not the other. Differences in selection may explain some of the observed phenotypic differentiation among depths for one trait but not another: instead, selection should actually erode the differences observed for this trait. Our results suggest selection is not acting alone to maintain trait variation within and across environments in this system.
authors: Centre for Geometric Biology/School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia. rolanda.lange@monash.edu.
authors: Rolanda
authors: R
authors: Lange
authors: Centre for Geometric Biology/School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia.
authors: Keyne
authors: K
authors: Monro
authors: Centre for Geometric Biology/School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia.
authors: Dustin
authors: D
authors: J Marshall
mesh_terms: D000818:Animals; D002013:Bryozoa / Q000235:genetics* / Q000502:physiology; D017753:Ecosystem; D005306:Fertilization; D014644:Genetic Variation; D000071421:Life History Traits; D012641:Selection, Genetic
keywords: Bryozoan; Watersipora; competition; growth; heterogeneous selection; natural selection