10.5061/DRYAD.61KR4
Bolnick, Daniel I.
The University of Texas at Austin
Stutz, William E.
The University of Texas at Austin
Data from: Frequency dependence limits divergent evolution by favouring
rare immigrants over residents
Dryad
dataset
2018
negative frequency dependent selection
migration-selection balance
Holocene
Gasterosteus aculeatus
National Science Foundation
https://ror.org/021nxhr62
DEB-1456462
2018-04-01T00:00:00Z
2018-04-01T00:00:00Z
en
https://doi.org/10.1038/nature22351
47951965 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Two distinct forms of natural selection promote adaptive biological
diversity. Divergent selection occurs when different environments favour
different phenotypes, leading to increased differences between
populations. Negative frequency-dependent selection occurs when rare
variants within a population are favoured over common ones, increasing
diversity within populations. These two diversifying forces promote
genetic variation at different spatial scales, and may act in opposition,
but their relative effects remain unclear because they are rarely measured
concurrently. Here we show that negative frequency-dependent selection
within populations can favor rare immigrants over locally adapted
residents. We reciprocally transplanted lake and stream ecotypes of
threespine stickleback into lake and stream habitats, while manipulating
the relative abundance of residents versus immigrants. We found negative
frequency-dependence: survival was highest for the locally rare ecotype,
rather than natives. Also, individuals with locally rare major
histocompatibility complex (MHC) class IIb genotypes were infected by
fewer parasites. This negative frequency-dependent selection will tend to
favour rare immigrants over common residents, amplifying the effect of
migration and undermining the efficacy of divergent natural selection to
drive population differences. The only signal of divergent selection was a
tendency for foreign fish to have higher parasite loads than residents,
after controlling for MHC genotype rarity. Frequency-dependent ecological
interactions have long been thought to promote speciation. Our results
suggest a more nuanced view in which negative frequency dependence alters
the fate of migrants to promote or constrain evolutionary divergence
between populations.
Bolnick traitsData on stickleback origin, destination, treatment,
phenotype, sex, growth, and
survivalBolnick_traits.txtBolnick_parasitesParasite load data on control
and recaptured caged stickleback.Bolnick_mhcMHC class IIb exon 2 genotype
data from released and recaptured stickleback.dna2protConverts MHC DNA
sequence haplotype identifiers into amino acid sequence
identifiersMHC_masterFASTA file of MHC sequence readsTAs_alnAligned
sequences of inferred alleles of MHC IIb exon 2.
Vancouver Island