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Mutualisms are mediated by adaptive traits of interacting organisms and play a central role in the ecology and evolution of species. Thousands of plant species possess tiny structures called “domatia” that house mites which protect plants from pests, yet these traits remain woefully understudied. Here, we release a worldwide database of species with mite domatia and provide an evaluation of the phylogenetic and geographic distribution of this mutualistic trait. With >2,500 additions based on digital herbarium scans and published reports, we increased the number of known species with domatia by 27% and, importantly, documented their absence in >4,000 species. We show that mite domatia likely evolved hundreds of times among flowering plants, occurring in an estimated ~10% of woody species representing over a quarter of all angiosperm families. Contrary to classic hypotheses about the evolutionary drivers of mutualism, we find that mite domatia evolved more frequently in temperate regions and in deciduous lineages; this pattern is concordant with a large-scale geographic transition from predominantly ant-based plant defense mutualisms in the tropics to mite-based defense mutualisms in temperate climates. Our data also reveal a pattern of evolutionary convergence in domatia morphology, with tuft-form domatia more likely to evolve in dry temperate habitats and pit domatia more likely to evolve in wet tropical environments. We have shown climate-associated drivers of mite domatia evolution, demonstrating their utility and power as an evolutionarily replicated system for the study of plant defense mutualisms.
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Convergent evolution of fern nectaries facilitated independent recruitment of ant-bodyguards from flowering plants
Abstract Plant–herbivore interactions reciprocally influence species’ evolutionary trajectories. These interactions have led to many physical and chemical defenses across the plant kingdom. Some plants have even evolved indirect defense strategies to outsource their protection to ant bodyguards by bribing them with a sugary reward (nectar). Identifying the evolutionary processes underpinning these indirect defenses provide insight into the evolution of plant-animal interactions. Using a cross-kingdom, phylogenetic approach, we examined the convergent evolution of ant-guarding nectaries across ferns and flowering plants. Here, we discover that nectaries originated in ferns and flowering plants concurrently during the Cretaceous, coinciding with the rise of plant associations in ants. While nectaries in flowering plants evolved steadily through time, ferns showed a pronounced lag of nearly 100 My between their origin and subsequent diversification in the Cenozoic. Importantly, we find that as ferns transitioned from the forest floor into the canopy, they secondarily recruited ant bodyguards from existing ant-angiosperm relationships.
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- PAR ID:
- 10509487
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Nature Communications
- Volume:
- 15
- Issue:
- 1
- ISSN:
- 2041-1723
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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