Background And Aims: The California Floristic Province (CA-FP) is the most species-rich region of North America north of Mexico. One of several proposed hypotheses explaining the exceptional diversity of the region is that the CA-FP harbours myriad recently diverged lineages with nascent reproductive barriers. Salvia subgenus Audibertia is a conspicuous element of the CA-FP, with multiple sympatric and compatible species.
View Article and Find Full Text PDFThe recent availability of open-access repositories of functional traits has revolutionized trait-based approaches in ecology and evolution. Nevertheless, the underrepresentation of tropical regions and lineages remains a pervasive bias in plant functional trait databases, which constrains large-scale assessments of plant ecology, evolution, and biogeography. Here, we present MelastomaTRAITs 1.
View Article and Find Full Text PDFPremise: Floral evolution in large clades is difficult to study not only because of the number of species involved, but also because they often are geographically widespread and include a diversity of outcrossing pollination systems. The cosmopolitan blueberry family (Ericaceae) is one such example, most notably pollinated by bees and multiple clades of nectarivorous birds.
Methods: We combined data on floral traits, pollination ecology, and geography with a comprehensive phylogeny to examine the structuring of floral diversity across pollination systems and continents.
We have previously suggested that a shift from bee to hummingbird pollination, in concert with floral architecture modifications, occurred at the crown of Salvia subgenus Calosphace in North America ca. 20 mya (Kriebel et al. 2020 and references therein).
View Article and Find Full Text PDFMany diverse plant clades possess bilaterally symmetrical flowers and specialised pollination syndromes, suggesting that these traits may promote diversification. We examined the evolution of diverse floral morphologies in a species-rich tropical radiation of Rhododendron. We used restriction-site associated DNA sequencing on 114 taxa from Rhododendron sect.
View Article and Find Full Text PDFNext-generation sequencing technologies have facilitated new phylogenomic approaches to help clarify previously intractable relationships while simultaneously highlighting the pervasive nature of incongruence within and among genomes that can complicate definitive taxonomic conclusions. L., with ∼1,000 species, makes up nearly 15% of the species diversity in the mint family and has attracted great interest from biologists across subdisciplines.
View Article and Find Full Text PDFPremise: We tested 25 classic and novel hypotheses regarding trait-origin, trait-trait, and trait-environment relationships to account for flora-wide variation in life history, habit, and especially reproductive traits using a plastid DNA phylogeny of most native (96.6%, or 1494/1547 species) and introduced (87.5%, or 690/789 species) angiosperms in Wisconsin, USA.
View Article and Find Full Text PDFSwitches in pollinators have been argued to be key drivers of floral evolution in angiosperms. However, few studies have tested the relationship between floral shape evolution and switches in pollination in large clades. In concert with a dated phylogeny, we present a morphometric analysis of corolla, anther connective, and style shape across 44% of nearly 1000 species of Salvia (Lamiaceae) and test four hypotheses of floral evolution.
View Article and Find Full Text PDFSpecies of plants with different life history strategies may differ in their seed dispersal mechanisms, impacting their distribution and diversification patterns. Shorter or longer distance dispersal is favored by different dispersal modes, facilitating (or constraining) population isolation, which can, in turn, impact speciation and species range sizes. While these associations are intuitive, few studies have explicitly tested these hypotheses for large clades of angiosperms.
View Article and Find Full Text PDFPremise Of The Study: A key question in evolutionary biology is why some clades are more successful by being widespread geographically, biome diverse, or species-rich. To extend understanding of how shifts in area, biomes, and pollinators impact diversification in plants, we examined the relationships of these shifts to diversification across the mega-genus Salvia.
Methods: A chronogram was developed from a supermatrix of anchored hybrid enrichment genomic data and targeted sequence data for over 500 of the nearly 1000 Salvia species.
Scorpions have evolved a variety of toxins with a plethora of biological targets, but characterizing their evolution has been limited by the lack of a comprehensive phylogenetic hypothesis of scorpion relationships grounded in modern, genome-scale datasets. Disagreements over scorpion higher-level systematics have also incurred challenges to previous interpretations of venom families as ancestral or derived. To redress these gaps, we assessed the phylogenomic relationships of scorpions using the most comprehensive taxonomic sampling to date.
View Article and Find Full Text PDFPremise Of The Study: We used spatial phylogenetics to analyze the assembly of the Wisconsin flora, linking processes of dispersal and niche evolution to spatial patterns of floristic and phylogenetic diversity and testing whether phylogenetic niche conservatism can account for these patterns.
Methods: We used digitized records and a new molecular phylogeny for 93% of vascular plants in Wisconsin to estimate spatial variation in species richness and phylogenetic α and β diversity in a native flora shaped mainly by postglacial dispersal and response to environmental gradients. We developed distribution models for all species and used these to infer fine-scale variation in potential diversity, phylogenetic distance, and interspecific range overlaps.
Syst Biol
September 2018
The goal of phylogenetic comparative methods (PCMs) is to study the distribution of quantitative traits among related species. The observed traits are often seen as the result of a Brownian Motion (BM) along the branches of a phylogenetic tree. Reticulation events such as hybridization, gene flow or horizontal gene transfer, can substantially affect a species' traits, but are not modeled by a tree.
View Article and Find Full Text PDFPremise Of The Study: Species formation is an intuitive endpoint of reproductive isolation, but circumscribing taxa that arise during speciation can be difficult because of gene flow, morphological continuity, hybridization or polyploidization, and low sequence variation among newly diverged lineages. Nonetheless, species complexes are ubiquitous, and their classification is essential for understanding how diversity influences ecosystem function.
Methods: We used modern sequencing technology to identify lineages of perennial Claytonia L.
Flower form is one of many floral features thought to be shaped by pollinator-mediated selection. Although the drivers of variation in flower shape have often been examined in microevolutionary studies, relatively few have tested the relationship between shape evolution and shifts in pollination system across clades. In the present study, we use morphometric approaches to quantify shape variation across the Andean clade Iochrominae and estimate the relationship between changes in shape and shifts in pollination system using phylogenetic comparative methods.
View Article and Find Full Text PDFThe study of pollen morphology has historically allowed evolutionary biologists to assess phylogenetic relationships among Angiosperms, as well as to better understand the fossil record. During this process, pollen has mainly been studied by discretizing some of its main characteristics such as size, shape, and exine ornamentation. One large plant clade in which pollen has been used this way for phylogenetic inference and character mapping is the order Myrtales, composed by the small families Alzateaceae, Crypteroniaceae, and Penaeaceae (collectively the "CAP clade"), as well as the large families Combretaceae, Lythraceae, Melastomataceae, Myrtaceae, Onagraceae and Vochysiaceae.
View Article and Find Full Text PDFMol Phylogenet Evol
December 2018
In our recent publication (Sharma et al., 2017), we tested the hypothesis that eggs attached to the legs of male Podoctidae (Opiliones, Laniatores) constituted a case of paternal care, using molecular sequence data in tandem with multiple sequence alignments to test the prediction that sequences of the eggs and the adults that carried them would indicate conspecific identity. We discovered that the sequences of the eggs belonged to spiders, and thus rejected the paternal care hypothesis for these species.
View Article and Find Full Text PDFPremise Of The Study: A recent commentary by Edwards et al. (. 103: 975-978) proposed that constraints imposed by the packing of young leaves in buds could explain the positive association between non-entire leaf margins and latitude but did not thoroughly consider alternative explanations.
View Article and Find Full Text PDFThe taxonomy and systematics of the armored harvestmen (suborder Laniatores) are based on various sets of morphological characters pertaining to shape, armature, pedipalpal setation, and the number of articles of the walking leg tarsi. Few studies have tested the validity of these historical character systems in a comprehensive way, with reference to an independent data class, i.e.
View Article and Find Full Text PDFA recent molecular phylogenetic analysis identified a clade containing all species of Conostegia, but that also included species of Clidemia and Miconia nested inside. A taxonomic revision of a more broadly circumscribed Conostegia is presented here. In total, 77 species of Conostegia are recognized.
View Article and Find Full Text PDFPremise Of The Study: The alternation of generations life cycle represents a key feature of land-plant evolution and has resulted in a diverse array of sporophyte forms and modifications in all groups of land plants. We test the hypothesis that evolution of sporangium (capsule) shape of the mosses-the second most diverse land-plant lineage-has been driven by differing physiological demands of life in diverse habitats. This study provides an important conceptual framework for analyzing the evolution of a single, homologous character in a continuous framework across a deep expanse of time, across all branches of the tree of life.
View Article and Find Full Text PDFMol Phylogenet Evol
February 2016
We examine the eudicot order Myrtales, a clade with strong Gondwanan representation for most of its families. Although previous phylogenetic studies greatly improved our understanding of intergeneric and interspecific relationships within the order, our understanding of inter-familial relationships still remains unresolved; hence, we also lack a robust time-calibrated chronogram to address hypotheses (e.g.
View Article and Find Full Text PDFProc Biol Sci
September 2015
Conostegia has been traditionally defined to consist of 42 species in the tribe Miconieae. Recent phylogenetic studies have cast doubt on the monophyly of the genus and highlighted the need for a phylogenetic study focused on Conostegia. The purpose of this study was to test the monophyly of Conostegia and address relationships in the genus.
View Article and Find Full Text PDF