Detecting local adaptation under weak genetic structure in an endemic damselfly: an integrative eco-evolutionary approach
Journal
BMC Ecology and Evolution
Journal Volume
26
Journal Issue
1
Start Page
Article number: 2
ISSN
2730-7182
Date Issued
2026-02-02
Author(s)
Abstract
Background
Insects comprise one of Earth’s most diverse animal groups, but the adaptive capacity of most species, especially those with weak genetic structure, remains understudied. Psolodesmus mandarinus is an endemic damselfly in Taiwan, where its populations show latitudinal variation in wing traits despite limited genetic differentiation in mitochondrial and ribosomal sequences. We hypothesised that weak genome-wide structure may obscure the signals of local adaptation driven by environmental variation. To test this, we integrated genome-wide SNPs, phenotypic measurements, environmental associations, and species distribution models.
Results
Although genome-wide population structure was generally weak, pairwise FST values exceeded 0.35 between southeastern and northeastern populations, and genetic-environment association analyses identified outlier loci and individuals associated with environmental variables. Wing traits, particularly wing colours, exhibited a latitudinal divergence and exceeded expectations from neutral structure (PST >FST), indicating selection. Species distribution models showed ecological differentiation and predicted range expansion for clear-winged individuals but range contraction for dark-winged individuals under future climate scenarios.
Conclusion
Our findings demonstrate that phenotypic divergence can arise and persist under weak genetic structure, highlighting the evolutionary potential for local adaptation in structured environments even in species with high dispersal potential. An integrative framework provides essential insights for predicting biodiversity responses to environmental change and guiding climate-resilient conservation strategies.
Subjects
Climate change resilience
Genetic structure
Genotype-environment association
Insect conservation
Landscape genomics
Local adaptation
Phenotypic plasticity
Species distribution modelling
Publisher
Springer Science and Business Media LLC
Type
journal article