Publication
Spatial phylogenetics of butterflies in relation to environmental drivers and angiosperm diversity across North America
Publisher:
Cold Spring Harbor Laboratory
Date:
24-07-2020
DOI:
10.1101/2020.07.22.216119
Abstract: Broad-scale quantitative assessments of bio ersity and the factors shaping it remain particularly poorly explored in insects. Here, we undertook a spatial phylogenetic analysis of North American butterflies via assembly of a time-calibrated phylogeny of the region coupled with a unique, complete range assessment for ~75% of the known species. We utilized a suite of phylo ersity metrics and associated environmental data to test whether climate stability and temperature gradients have shaped North American butterfly phylogenetic ersity and endemism. We also undertook the first direct, quantitative comparisons of spatial phylogenetic patterns between butterflies and flowering plants in North America. We expected concordance between butterflies and angiosperms based on both shared historical environmental drivers and presumed strong butterfly-host plant specializations. We instead found that bio ersity patterns in butterflies are strikingly different from flowering plants in some regions of the continent. In particular, the warm desert regions of the southwestern United States and Mexico showed surprisingly high butterfly phylogenetic ersity and endemism, in contrast to much lower values for angiosperms. Butterflies did not show patterns of phylogenetic clustering as found in flowering plants, suggesting differences in habitat conservation between the two groups. Finally, we found weak relationships and spatially structured biases in relative branching timing between angiosperms and butterflies. These results suggest that shared biogeographic histories and trophic associations do not necessarily assure similar ersity outcomes. The work has applied value in conservation planning, documenting warm deserts as an important North American butterfly bio ersity hotspot.