Microhabitat contributes to microgeographic divergence in threespine stickleback

Since the New Synthesis, most migration-selection balance theory has predicted that there should be negligible differentiation over small spatial scales (relative to dispersal), because gene flow should erode any effect of divergent selection. Nevertheless, there are classic examples of microgeograp...

Full description

Saved in:
Bibliographic Details
Published in:Evolution 2020-04, Vol.74 (4), p.749-763
Main Authors: Maciejewski, Meghan F., Jiang, Cynthia, Stuart, Yoel E., Bolnick, Daniel I.
Format: Article
Language:English
Subjects:
Adaptation, Physiological - genetics
Animal behavior
Animals
Biological Evolution
British Columbia
Dispersal
dispersal neighborhood
Dispersion
Divergence
Ecosystem
Female
Fish populations
Gasterosteus aculeatus
Gene flow
Genetic isolation
Genotype
Genotypes
Habitat preferences
Habitats
Lakes
Male
Microenvironments
Microhabitats
migration‐selection balance
Morphology
Multivariate Analysis
ORIGINAL ARTICLE
Phenotype
Phenotypic plasticity
Populations
Smegmamorpha - anatomy & histology
Smegmamorpha - genetics
Substrates
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Since the New Synthesis, most migration-selection balance theory has predicted that there should be negligible differentiation over small spatial scales (relative to dispersal), because gene flow should erode any effect of divergent selection. Nevertheless, there are classic examples of microgeographic divergence, which theory suggests can arise under specific conditions: exceptionally strong selection, phenotypic plasticity in philopatric individuals, or nonrandom dispersal. Here, we present evidence of microgeographic morphological variation within lake and stream populations of threespine stickleback (Gasterosteus aculeatus). It seems reasonable to assume that a given lake or stream population of fish is well-mixed. However, we found this assumption to be untenable. We examined trap-to-trap variation in 34 morphological traits measured on stickleback from 16 lakes and 16 streams. Most traits varied appreciably among traps within populations. Both between-trap distance and microhabitat characteristics such as depth and substrate explained some of the within-population morphological variance. Microhabitat was also associated with genotype at particular loci but there was no genetic isolation by distance, implying that heritable habitat preferences may contribute to microgeographic variation. Our study adds to growing evidence that microgeographic divergence can occur across small spatial scales within individuals’daily dispersal neighborhood where gene flow is expected to be strong.
ISSN:0014-3820
1558-5646
DOI:10.1111/evo.13942