Data from: Anthropogenic ecosystem fragmentation drives shared and unique patterns of sexual signal divergence among three species of Bahamian mosquitofish

When confronted with similar environmental challenges, different organisms
can exhibit dissimilar phenotypic responses. Therefore, understanding
patterns of phenotypic divergence for closely related species requires
considering distinct evolutionary histories. Here, we investigated how a
common form of human-induced environmental alteration, habitat
fragmentation, may drive phenotypic divergence among three closely related
species of Bahamian mosquitofish (Gambusia spp.). Focusing on one
phenotypic trait (male coloration), having a priori predictions of
divergence, we tested whether populations persisting in fragmented
habitats differed from those inhabiting unfragmented habitats and examined
the consistency of the pattern across species. Species exhibited both
shared and unique patterns of phenotypic divergence between the two types
of habitats, with shared patterns representing the stronger effect. For
all species, populations in fragmented habitats had fewer dorsal-fin
spots. In contrast, the magnitude and trajectory of divergence in
dorsal-fin color, a sexually selected trait, differed among species. We
identified fragmentation-mediated increased turbidity as a possible driver
of these trait shifts. These results suggest that even closely related
species can exhibit diverse phenotypic responses when encountering similar
human-mediated selection regimes. This element of unpredictability
complicates forecasting the phenotypic responses of wild organisms faced
with anthropogenic change – an important component of biological
conservation and ecosystem management.