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Morphological variation over ontogeny and environments in resource polymorphic arctic charr (Salvelinus alpinus)
Kevin J Parsons1, Skuli Skúlason, Moira Ferguson
1Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada. kjpars01@syr.edu
Evolution & Development
|June 23, 2010
Summary
Natural selection shapes development, with specialized Arctic charr showing reduced shape variation over time. Environmental changes can alter this process, influencing the genetic variation available for adaptation.
Area of Science:
- Evolutionary Biology
- Developmental Biology
- Ecology
Background:
- Natural selection drives adaptive evolution by acting on genetically based phenotypic variation.
- Morphological development can become canalized (buffered from environmental effects) through selection.
- The influence of selection on canalization across ontogeny and varying environments remains poorly understood.
Purpose of the Study:
- To investigate how natural selection affects developmental canalization in Arctic charr (Salvelinus alpinus) across ontogeny and different environments.
- To determine if ecological specialization influences the degree of canalization.
- To explore the role of environmental conditions in modulating phenotypic variation exposed to selection.
Main Methods:
- Studied Arctic charr ecomorphs from two Icelandic lakes with differing ecological specialization.
- Analyzed changes in phenotypic (shape) variation over ontogeny and across different environmental treatments.
- Compared variation patterns between highly specialized and less specialized ecomorphs.
Main Results:
- Highly specialized ecomorphs in both lakes exhibited reduced shape variation over ontogeny, indicating canalized development.
- Environmental treatments did not eliminate canalization but influenced the amount of shape variation expressed.
- Novel environments slowed the rate of variation reduction during ontogeny for specialized ecomorphs.
Conclusions:
- Ecological specialization leads to canalized development, reducing phenotypic variation over ontogeny.
- Environmental conditions play a significant role in modulating the amount of phenotypic variation available for natural selection.
- Understanding these interactions is crucial for predicting adaptive divergence in novel environments.
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