Environment-dependent inbreeding depression: its ecological and evolutionary significance

Authors

  • Pierre-Olivier Cheptou,

    1. UMR 5175 CEFE – Centre d’Ecologie Fonctionnelle et Evolutive (CNRS), 1919 Route de Mende, F-34293 Montpellier, Cedex 05, France
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    • These authors contributed equally to this work.

  • Kathleen Donohue

    1. Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
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    • These authors contributed equally to this work.


Author for correspondence:
Pierre-Olivier Cheptou
Tel : +33 (0) 4 67 61 32 68
Email: pierre-olivier.cheptou@cefe.cnrs.fr

Abstract

Contents

 Summary395
I.Introduction396
II.What is inbreeding depression?396
III.Causes of environment-dependent inbreeding depression397
IV.Ecological and evolutionary consequences of environment-dependent inbreeding depression401
V.Feedbacks when inbreeding depression influences the environment404
VI.Conclusions and future directions405
 Acknowledgements406
 References406

Summary

Inbreeding depression is a major evolutionary and ecological force that influences population dynamics and the evolution of inbreeding-avoidance traits such as mating systems and dispersal. There is now compelling evidence that inbreeding depression is environment-dependent. Here, we discuss ecological and evolutionary consequences of environment-dependent inbreeding depression. The environmental dependence of inbreeding depression may be caused by environment-dependent phenotypic expression, environment-dependent dominance, and environment-dependent natural selection. The existence of environment-dependent inbreeding depression challenges classical models of inbreeding as caused by unconditionally deleterious alleles, and suggests that balancing selection may shape inbreeding depression in natural populations; loci associated with inbreeding depression in some environments may even contribute to adaptation to others. Environment-dependent inbreeding depression also has important, often neglected, ecological and evolutionary consequences: it can influence the demography of marginal or colonizing populations and alter adaptive optima of mating systems, dispersal, and their associated traits. Incorporating the environmental dependence of inbreeding depression into theoretical models and empirical studies is necessary for understanding the genetic and ecological basis of inbreeding depression and its consequences in natural populations.

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