Genetic and demographic founder effects have long‐term fitness consequences for colonising populations |
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| Authors: | Marianna Sz?cs Brett A Melbourne Ty Tuff Christopher Weiss‐Lehman Ruth A Hufbauer |
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| Affiliation: | 1. Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, USA;2. Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA;3. Department of Biology, Washington University in St. Louis, St. Louis, MO, USA;4. Max Planck Institute for the Science of Human History, Jena, Germany |
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| Abstract: | Colonisation is a fundamental ecological and evolutionary process that drives the distribution and abundance of organisms. The initial ability of colonists to establish is determined largely by the number of founders and their genetic background. We explore the importance of these demographic and genetic properties for longer term persistence and adaptation of populations colonising a novel habitat using experimental populations of Tribolium castaneum. We introduced individuals from three genetic backgrounds (inbred – outbred) into a novel environment at three founding sizes (2–32), and tracked populations for seven generations. Inbreeding had negative effects, whereas outbreeding generally had positive effects on establishment, population growth and long‐term persistence. Severe bottlenecks due to small founding sizes reduced genetic variation and fitness but did not prevent adaptation if the founders originated from genetically diverse populations. Thus, we find important and largely independent roles for both demographic and genetic processes in driving colonisation success. |
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| Keywords: | Adaptation admixture colonisation demography extinction founder effects genetic diversity inbreeding population founding |
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