title: The predictability and magnitude of life-history divergence to ecological agents of selection: a meta-analysis in livebearing fishes.
abstract: Environments causing variation in age-specific mortality - ecological agents of selection - mediate the evolution of reproductive life-history traits. However, the relative magnitude of life-history divergence across selective agents, whether divergence in response to specific selective agents is consistent across taxa and whether it occurs as predicted by theory, remains largely unexplored. We evaluated divergence in offspring size, offspring number, and the trade-off between these traits using a meta-analysis in livebearing fishes (Poeciliidae). Life-history divergence was consistent and predictable to some (predation, hydrogen sulphide) but not all (density, food limitation, salinity) selective agents. In contrast, magnitudes of divergence among selective agents were similar. Finally, there was a negative, asymmetric relationship between offspring-number and offspring-size divergence, suggesting greater costs of increasing offspring size than number. Ultimately, these results provide strong evidence for predictable and consistent patterns of reproductive life-history divergence and highlight the importance of comparing phenotypic divergence across species and ecological selective agents.
authors.affiliation: Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA.
authors.forename: Michael P
authors.identifier: http://orcid.org/0000-0002-8255-4247
authors.initials: MP
authors.lastname: Moore
authors.affiliation: School of Biological Sciences, Royal Holloway, University of London, Egham, TW20 0EX, UK.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Riesch
authors.affiliation: Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA.
authors.forename: Ryan A
authors.identifier: http://orcid.org/0000-0002-7448-5907
authors.initials: RA
authors.lastname: Martin
mesh_terms: D000818:Animals; D017753:Ecosystem; D008954:Models, Biological; D011036:Poecilia / Q000502:physiology*; D012098:Reproduction / Q000502:physiology; D012641:Selection, Genetic
keywords: Divergent natural selection; Poeciliidae; life-history evolution; maternal investment; reproductive allocation