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1. The evolution of hummingbird pollination is common across angiosperm lineages throughout the Americas, presenting an opportunity to examine convergence in both traits and environments to better understand how complex phenotypes arise. We examine multiple independent shifts from bee to hummingbird pollination in the Neotropical spiral gingers (Costus) and use our data to address several common explanations for the prevalence of bee to bird pollination transitions. 2. We use floral traits of species with observed pollinators to predict pollinators of unobserved species and reconstruct ancestral pollination states on a well-resolved phylogeny. We examine whether independent transitions evolve towards the same phenotypic optimum and whether shifts to hummingbird pollination are associated with high elevation or climatic niche. 3. Traits predicting hummingbird pollination include small flower size, brightly-colored floral bracts, and the absence of nectar guides. We find many shifts to hummingbird pollination and no reversals, a single shared phenotypic optimum across hummingbird flowers, and no association between pollination and elevation or climatic niche. 4. Costus presents surprising findings compared to other plant clades. Hummingbird flowers are consistently smaller than bee flowers and primary flower colors are not predictive of pollinators. Moreover, hummingbird pollination shows no association with high elevation, as found in other tropical plants.
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Evolutionary convergence on hummingbird pollination in Neotropical Costus provides insight into the causes of pollinator shifts
Summary The evolution of hummingbird pollination is common across angiosperms throughout the Americas, presenting an opportunity to examine convergence in both traits and environments to better understand how complex phenotypes arise. Here we examine independent shifts from bee to hummingbird pollination in the Neotropical spiral gingers (Costus) and address common explanations for the prevalence of transitions from bee to hummingbird pollination.We use floral traits of species with observed pollinators to predict pollinators of unobserved species and reconstruct ancestral pollination states on a well‐resolved phylogeny. We examine whether independent transitions evolve towards the same phenotypic optimum and whether shifts to hummingbird pollination correlate with elevation or climate.Traits predicting hummingbird pollination include small flower size, brightly colored floral bracts and the absence of nectar guides. We find many shifts to hummingbird pollination and no reversals, a single shared phenotypic optimum across hummingbird flowers, and no association between pollination and elevation or climate.Evolutionary shifts to hummingbird pollination inCostusare highly convergent and directional, involve a surprising set of traits when compared with other plants with analogous transitions and refute the generality of several common explanations for the prevalence of transitions from bee to hummingbird pollination.
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- PAR ID:
- 10392935
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- New Phytologist
- Volume:
- 236
- Issue:
- 4
- ISSN:
- 0028-646X
- Page Range / eLocation ID:
- p. 1572-1583
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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