TY - JOUR
T1 - The temporal build-up of hummingbird/plant mutualisms in North America and temperate South America
AU - Abrahamczyk, Stefan
AU - Renner, Susanne S.
N1 - Publisher Copyright:
© 2015 Abrahamczyk and Renner.
PY - 2015/12/12
Y1 - 2015/12/12
N2 - Background: The 361 species of hummingbirds that occur from Alaska to Patagonia pollinate ~7,000 plant species with flowers morphologically adapted to them. To better understand this asymmetric diversity build-up, this study analyzes the origin of hummingbird/plant mutualisms in North America and temperate South America, based on new compilations of the 184 hummingbird-adapted species in North America, the 56 in temperate South America, and complete species-level phylogenies for the relevant hummingbirds in both regions, namely five in temperate South America and eight in North America. Because both floras are relatively well sampled phylogenetically, crown or stem ages of many representative clades could be inferred. The hummingbird chronogram was calibrated once with fossils, once with substitutions rates, while plant chronograms were taken from the literature or in 13 cases newly generated. Results: The 184 North American hummingbird-adapted species belong to ca. 70 lineages for 19 of which (comprising 54 species) we inferred divergence times. The 56 temperate South American hummingbird-adapted species belong to ca. 35 lineages, for 17 of which (comprising 25 species) we inferred divergence times. The oldest hummingbirds and hummingbird-adapted plant lineages in the South American assemblage date to 16-17 my, those in the North American assemblage to 6-7 my. Few hummingbird-pollinated clades in either system have >4 species. Conclusions: The asymmetric diversity build-up between hummingbirds and the plants dependent on them appears to arise not from rapid speciation within hummingbird-pollinated clades, but instead from a gradual and continuing process in which independent plant species switch from insect to bird pollination. Diversification within hummingbird-pollinated clades in the temperate regions of the Americas appears mainly due to habitat specialization and allopatric speciation, not bird pollination per se. Interaction tanglegrams, even if incomplete, indicate a lack of tight coevolution as perhaps expected for temperate-region mutualisms involving nectar-feeding vertebrates.
AB - Background: The 361 species of hummingbirds that occur from Alaska to Patagonia pollinate ~7,000 plant species with flowers morphologically adapted to them. To better understand this asymmetric diversity build-up, this study analyzes the origin of hummingbird/plant mutualisms in North America and temperate South America, based on new compilations of the 184 hummingbird-adapted species in North America, the 56 in temperate South America, and complete species-level phylogenies for the relevant hummingbirds in both regions, namely five in temperate South America and eight in North America. Because both floras are relatively well sampled phylogenetically, crown or stem ages of many representative clades could be inferred. The hummingbird chronogram was calibrated once with fossils, once with substitutions rates, while plant chronograms were taken from the literature or in 13 cases newly generated. Results: The 184 North American hummingbird-adapted species belong to ca. 70 lineages for 19 of which (comprising 54 species) we inferred divergence times. The 56 temperate South American hummingbird-adapted species belong to ca. 35 lineages, for 17 of which (comprising 25 species) we inferred divergence times. The oldest hummingbirds and hummingbird-adapted plant lineages in the South American assemblage date to 16-17 my, those in the North American assemblage to 6-7 my. Few hummingbird-pollinated clades in either system have >4 species. Conclusions: The asymmetric diversity build-up between hummingbirds and the plants dependent on them appears to arise not from rapid speciation within hummingbird-pollinated clades, but instead from a gradual and continuing process in which independent plant species switch from insect to bird pollination. Diversification within hummingbird-pollinated clades in the temperate regions of the Americas appears mainly due to habitat specialization and allopatric speciation, not bird pollination per se. Interaction tanglegrams, even if incomplete, indicate a lack of tight coevolution as perhaps expected for temperate-region mutualisms involving nectar-feeding vertebrates.
KW - Chronograms
KW - Coevolution
KW - Hummingbirds
KW - Patagonia
KW - Sephanoides
KW - Staggered clade ages
UR - http://www.scopus.com/inward/record.url?scp=84939254727&partnerID=8YFLogxK
U2 - 10.1186/s12862-015-0388-z
DO - 10.1186/s12862-015-0388-z
M3 - Article
C2 - 26058608
AN - SCOPUS:84939254727
SN - 1471-2148
VL - 15
JO - BMC Evolutionary Biology
JF - BMC Evolutionary Biology
IS - 1
M1 - 104
ER -