TY - JOUR
T1 - Global dynamics of dispersal and diversification among passerine birds
AU - Kennedy, Jonathan David
PY - 2017
Y1 - 2017
N2 - Explaining global variation in geographic and taxonomic diversity gradients represents a central focus of macroecology and macroevolution. Ultimately, these diversity gradients have been generated over deep timescales as a consequence of historical variation in rates of dispersal, diversification, and the capacity of different geographic areas to preserve taxa through time. Here, I assess the relationships among these processes, to elucidate the causes of geographic and taxonomic variation in species richness among the most speciose order of birds: the Passeriformes (c. 6,500 species). To achieve this, I comparatively analyze phylogenetic, distributional and ecomorphological trait data collated at broad taxonomic and spatial scales. The results of my analyses strongly support the prevalence of historical dispersal events across large geographic scales, in addition to spatiotemporal variation in diversification rates. These findings reflect that some lineages and some geographic regions (notably tropical mountain regions and island archipelagoes) generate and maintain a much larger amount of species diversity than others. In addition, the evolution of particular life-history and eco-morphological traits, specifically pair breeding systems, and higher wing aspect-ratios, increased rates of range expansion and diversification. In summary, geographic variation in historical diversification combined with differences in the capacity of lineages to colonize new areas, determines spatial and taxonomic differences in passerine species richness.
AB - Explaining global variation in geographic and taxonomic diversity gradients represents a central focus of macroecology and macroevolution. Ultimately, these diversity gradients have been generated over deep timescales as a consequence of historical variation in rates of dispersal, diversification, and the capacity of different geographic areas to preserve taxa through time. Here, I assess the relationships among these processes, to elucidate the causes of geographic and taxonomic variation in species richness among the most speciose order of birds: the Passeriformes (c. 6,500 species). To achieve this, I comparatively analyze phylogenetic, distributional and ecomorphological trait data collated at broad taxonomic and spatial scales. The results of my analyses strongly support the prevalence of historical dispersal events across large geographic scales, in addition to spatiotemporal variation in diversification rates. These findings reflect that some lineages and some geographic regions (notably tropical mountain regions and island archipelagoes) generate and maintain a much larger amount of species diversity than others. In addition, the evolution of particular life-history and eco-morphological traits, specifically pair breeding systems, and higher wing aspect-ratios, increased rates of range expansion and diversification. In summary, geographic variation in historical diversification combined with differences in the capacity of lineages to colonize new areas, determines spatial and taxonomic differences in passerine species richness.
KW - Diversification rates
KW - Islands
KW - Macroevolution
KW - Mountains
KW - Speciation
KW - Species richness
UR - http://www.scopus.com/inward/record.url?scp=85018443494&partnerID=8YFLogxK
U2 - 10.21425/F59132645
DO - 10.21425/F59132645
M3 - Journal article
AN - SCOPUS:85018443494
SN - 1948-6596
VL - 9
JO - Frontiers of Biogeography
JF - Frontiers of Biogeography
IS - 1
ER -