Open AccessEnvironmental selection is a main driver of divergence in house sparrows ( Passer domesticus ) in Romania and Bulgaria
Author(s) -
Geue Julia C.,
Vágási Csongor I.,
Schweizer Mona,
Pap Péter L.,
Thomassen Henri A.
Publication year - 2016
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.2509
Subject(s) - adaptation (eye) , ecology , divergence (linguistics) , natural selection , ecological selection , population , selection (genetic algorithm) , local adaptation , biology , resistance (ecology) , environmental change , genetic divergence , geography , genetic diversity , evolutionary biology , climate change , demography , philosophy , linguistics , neuroscience , artificial intelligence , sociology , computer science
Both neutral and adaptive evolutionary processes can cause population divergence, but their relative contributions remain unclear. We investigated the roles of these processes in population divergence in house sparrows ( Passer domesticus ) from Romania and Bulgaria, regions characterized by high landscape heterogeneity compared to Western Europe. We asked whether morphological divergence, complemented with genetic data in this human commensal species, was best explained by environmental variation, geographic distance, or landscape resistance—the effort it takes for an individual to disperse from one location to the other—caused by either natural or anthropogenic barriers. Using generalized dissimilarity modeling, a matrix regression technique that fits biotic beta diversity to both environmental predictors and geographic distance, we found that a small set of climate and vegetation variables explained up to ~30% of the observed divergence, whereas geographic and resistance distances played much lesser roles. Our results are consistent with signals of selection on morphological traits and of isolation by adaptation in genetic markers, suggesting that selection by natural environmental conditions shapes population divergence in house sparrows. Our study thus contributes to a growing body of evidence that adaptive evolution may be a major driver of diversification.