More Like this

1. Extending phylogenetic regression models for comparing within‐species patterns across the tree of life

   https://doi.org/10.1111/2041-210X.14438  

   Adams, Dean C; Collyer, Michael L (December 2024, Methods in Ecology and Evolution)

   Abstract Evolutionary biologists characterize macroevolutionary trends of phenotypic change across the tree of life using phylogenetic comparative methods. However, within‐species variation can complicate such investigations. For this reason, procedures for incorporating nonstructured (random) intraspecific variation have been developed.Likewise, evolutionary biologists seek to understand microevolutionary patterns of phenotypic variation within species, such as sex‐specific differences or allometric trends. Additionally, there is a desire to compare such within‐species patterns across taxa, but current analytical approaches cannot be used to interrogate within‐species patterns while simultaneously accounting for phylogenetic non‐independence. Consequently, deciphering how intraspecific trends evolve remains a challenge.Here we introduce an extended phylogenetic generalized least squares (E‐PGLS) procedure which facilitates comparisons of within‐species patterns across species while simultaneously accounting for phylogenetic non‐independence.Our method uses an expanded phylogenetic covariance matrix, a hierarchical linear model, and permutation methods to obtain empirical sampling distributions and effect sizes for model effects that can evaluate differences in intraspecific trends across species for both univariate and multivariate data, while conditioning them on the phylogeny.The method has appropriate statistical properties for both balanced and imbalanced data. Additionally, the procedure obtains evolutionary covariance estimates that reflect those from existing approaches for nonstructured intraspecific variation. Importantly, E‐PGLS can detect differences in structured (i.e. microevolutionary) intraspecific patterns across species when such trends are present. Thus, E‐PGLS extends the reach of phylogenetic comparative methods into the intraspecific comparative realm, by providing the ability to compare within‐species trends across species while simultaneously accounting for shared evolutionary history. 

   more » « less
2. Concentrated vulnerabilities in bees: Diet specialists have smaller geographic ranges

   https://doi.org/10.1111/icad.70086  

   Thrift, Charles N; Wood, Thomas J; Bui, An; Young, Hillary S; Seltmann, Katja C (May 2026, Insect Conservation and Diversity)

   Abstract Wild bees are widely believed to be in decline, yet most species remain unassessed for IUCN extinction risk. Geographic range size is used in risk assessments under the assumption that species with smaller ranges are more vulnerable to anthropogenic impacts. Narrow diet breadth can also increase vulnerability but is not currently incorporated into assessments.Niche breadth theory predicts a positive association between range size and diet breadth, which could concentrate risk among dietary specialists, but this relationship is not well established for bees and may differ among taxa.Here, we combined pollen‐use data from natural history collections with global occurrence records to test the relationship between diet breadth and range size across bees and among bee families. We assigned diet breadth using three metrics (categorical, numerical and phylogenetic) and estimated range size as the extent of occurrence for 633 species from six families.Across bees, range size increased with diet breadth, and diet specialists tended to occupy smaller ranges. These results suggest that range size and diet breadth jointly contribute to increased vulnerability in bees, indicating that some specialist species may merit conservation prioritisation.Our findings support the integration of trait‐based approaches for assessing extinction risk and highlight the high value of natural history data in identifying patterns of vulnerability among pollinators. 

   more » « less
3. Foliar spectral signatures reveal adaptive divergence in live oaks ( Quercus section Virentes ) across species and environmental niches

   https://doi.org/10.1111/nph.70424  

   Hernández‐Leal, Mariana S; Guzmán_Q, J Antonio; González‐Rodríguez, Antonio; Cavender‐Bares, Jeannine (October 2025, New Phytologist)

   Summary Genomic tools have advanced our understanding of species and population structure, but distinguishing neutral from adaptive evolution remains challenging due to limited methods for measuring a broad spectrum of phenotypic traits.We used spectroscopic data from preserved leaves to test for adaptive divergence among populations of live oaks (QuercussectionVirentes), a monophyletic group of seven species that diversified under sympatric, parapatric, and allopatric speciation. We used 427 individuals to test for isolation‐by‐distance (IBD) and isolation‐by‐environment (IBE), as well as the influences of selection and phylogenetic inertia on traits. Finally, we examined how phylogenetic signals are distributed across their foliar reflectance spectra.Partial redundancy analyses revealed that IBE explains more phenotypic variation than IBD among sympatric species, particularly in certain spectral regions and traits derived from spectra. Phylogenetic generalized least squares models show that environmental variables – including minimum temperature of the coldest month and annual precipitation – predict traits related to stress tolerance across climatic gradients, such as lignin concentration and anthocyanin levels.These results demonstrate that foliar reflectance spectra can be used to capture adaptive differentiation and evolutionary history across scales, offering a powerful, nondestructive tool for linking phenotype, environment, and evolutionary processes in long‐lived plant lineages. 

   more » « less
4. Evolutionary lineage explains trait variation among 75 coexisting grass species

   https://doi.org/10.1111/nph.18983  

   Donnelly, Ryan C.; Wedel, Emily R.; Taylor, Jeffrey H.; Nippert, Jesse B.; Helliker, Brent R.; Riley, William J.; Still, Christopher J.; Griffith, Daniel M. (August 2023, New Phytologist)

   Summary Evolutionary history plays a key role driving patterns of trait variation across plant species. For scaling and modeling purposes, grass species are typically organized into C₃vs C₄plant functional types (PFTs). Plant functional type groupings may obscure important functional differences among species. Rather, grouping grasses by evolutionary lineage may better represent grass functional diversity.We measured 11 structural and physiological traitsin situfrom 75 grass species within the North American tallgrass prairie. We tested whether traits differed significantly among photosynthetic pathways or lineages (tribe) in annual and perennial grass species.Critically, we found evidence that grass traits varied among lineages, including independent origins of C₄photosynthesis. Using a rigorous model selection approach, tribe was included in the top models for five of nine traits for perennial species. Tribes were separable in a multivariate and phylogenetically controlled analysis of traits, owing to coordination of important structural and ecophysiological characteristics.Our findings suggest grouping grass species by photosynthetic pathway overlooks variation in several functional traits, particularly for C₄species. These results indicate that further assessment of lineage‐based differences at other sites and across other grass species distributions may improve representation of C₄species in trait comparison analyses and modeling investigations. 

   more » « less
5. Differential effects of pollen nutritional quality on male and female reproductive success within a diverse co‐flowering community

   https://doi.org/10.1111/1365-2435.14703  

   Russo, Laura; Carneiro, Liedson Tavares; Williams, Jessica N; Barker, Daniel A; Murray, Anne; Arceo‐Gómez, Gerardo (January 2025, Functional Ecology)

   Abstract Pollen protein content has been demonstrated to be an essential nutritional component for bees and thus important in mediating plant–pollinator interactions. However, little is known on the drivers and consequences of among‐species variation in pollen protein content and how this can impact male and female reproductive success across plant species. Among‐species variation in resources allocated to pollen nutrition could further be constrained by life‐history strategies (e.g. survival‐reproduction trade‐offs) or evolutionary history.Here, we surveyed pollen protein content for 29 species within a diverse co‐flowering community and evaluated the effect of pollen protein on male and female reproductive success. We also tested the role of life history (annuals vs. perennials) and phylogeny in mediating differences in resource allocation to pollen nutrition.We found that pollen protein content influences components of male (bee visitor abundance and pollen dispersal) but not female (conspecific pollen deposition and pollen tube growth) reproductive success, suggesting this trait affects plants only via male function. This sex‐specific effect further suggests the potential for sexual conflicts driven by differential investment on this trait. We found no phylogenetic signal on pollen protein content. However, pollen protein content was higher in annual compared to perennial species suggesting survival versus reproduction trade‐offs also contribute to variation in pollen protein at the community level.Our study underscores the importance of understanding the ecological and evolutionary drivers of pollen protein content across plant species. Our results further suggest the existence of sexual conflicts and ecological trade‐offs mediated by differential investment in pollen nutritional quality, with important implications for community assembly and the structure of plant–pollinator interactions. Read the freePlain Language Summaryfor this article on the Journal blog. 

   more » « less