Eco-evolutionary interactions following ecosystem change provide critical insight into the ability of organisms to adapt to shifting resource landscapes. Here we explore evidence for the rapid parallel evolution of trout feeding morphology following eco-evolutionary interactions with zooplankton in alpine lakes stocked at different points in time in the Wind River Range (Wyoming, USA). In this system, trout predation has altered the zooplankton species community and driven a decrease in average zooplankton size. In some lakes that were stocked decades ago, we find shifts in gill raker traits consistent with the hypothesis that trout have rapidly adapted to exploit available smaller-bodied zooplankton more effectively. We explore this morphological response in multiple lake populations across two species of trout (cutthroat trout, Oncorhynchus clarkii, and golden trout Oncorhynchus aguabonita) and examine the impact of resource availability on morphological variation in gill raker number among lakes. Furthermore, we present genetic data to provide evidence that historically stocked cutthroat trout populations likely derive from multiple population sources, and incorporate variation from genomic relatedness in our exploration of environmental predictors of feeding morphology. These findings describe rapid adaptation and eco-evolutionary interactions in trout and document an evolutionary response to novel, contemporary ecosystem change.
Species introductions provide opportunities to quantify rates and patterns of evolutionary change in response to novel environments. Alewives (
- Award ID(s):
- 1754627
- NSF-PAR ID:
- 10378411
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Evolutionary Applications
- Volume:
- 13
- Issue:
- 10
- ISSN:
- 1752-4571
- Page Range / eLocation ID:
- p. 2630-2645
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Aim Natural selection typically results in the homogenization of reproductive traits, reducing natural variation within populations; thus, highly polymorphic species present unresolved questions regarding the mechanisms that shape and maintain gene flow given a diversity of phenotypes. We used an integrative framework to characterize phenotypic diversity and assess how evolutionary history and population genetics affect the highly polymorphic nature of a California endemic lily.
Location California, United States.
Taxon Butterfly mariposa lily,
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Results Polymorphic floral traits within the species such as petal pigmentation and distal spots are geographically structured, and inferred evolutionary history is consistent with a ring species pattern involving a complex of populations having experienced sequential change in genetic and phenotypic variation from the founding population. Populations remain interconnected yet have differentiated from each other along a bifurcating south‐to‐north range expansion, consequently indicating parallel evolution towards the white morphotype in the northern range. Thus, our phylogeographical analyses reveal morphological convergence with population genetic cohesion irrespective of phenotypic diversity.
Main conclusions Phenotypic variation in the highly polymorphic
Calochortus venustus is not due to genetic differentiation between phenotypes; rather there is genetic cohesion within six geographically defined populations, some of which maintain a high level of within‐population phenotypic diversity. Our results demonstrate that analyses of polymorphic taxa greatly benefit from disentangling phenotype from genotype at various spatial scales. We discuss results in light of ring species concepts and the need to determine the adaptive significance of the patterns we report. -
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