Paleogene Radiation of a Plant Pathogenic Mushroom

Background: The global movement and speciation of fungal plant pathogens is important, especially because of the economic losses they cause and the ease with which they are able to spread across large areas. Understanding the biogeography and origin of these plant pathogens can provide insights regarding their dispersal and current day distribution. We tested the hypothesis of a Gondwanan origin of the plant pathogenic mushroom genus Armillaria and the currently accepted premise that vicariance accounts for the extant distribution of the species. Methods: The phylogeny of a selection of Armillaria species was reconstructed based on Maximum Parsimony (MP), Maximum Likelihood (ML) and Bayesian Inference (BI). A timeline was then placed on the divergence of lineages using a Bayesian relaxed molecular clock approach. Results: Phylogenetic analyses of sequenced data for three combined nuclear regions provided strong support for three major geographically defined clades: Holarctic, South American-Australasian and African. Molecular dating placed the initial radiation of the genus at 54 million years ago within the Early Paleogene, postdating the tectonic break-up of Gondwana. Conclusions: The distribution of extant Armillaria species is the result of ancient long-distance dispersal rather than vicariance due to continental drift. As these finding are contrary to most prior vicariance hypotheses for fungi, our result

The ecology of morphology: the ecometrics of locomotion and macroenvironment in North American snakes - Online Appendix

Morphological traits that have a functional relationship with the environment can be used to study relationships between organisms and environments through time and across space. Dynamics of the trait-environment complex can be studied with ecometrics in individuals, in populations, and in communities. We explored how closely correlated three skeletal traits are with substrate use, and thus macrohabitat, among communities of snakes with the goal of better understanding how climate and macrovegetation might affect snake assemblages. Substrate use explained a large part of the variance in mean length-to-width ratio of vertebrae (R2 = 0.66), PC1 of vertebral shape of a mid trunk vertebra (R2 = 0.46), and relative tail length (R2 = 0.71). Furthermore, mean relative tail length in snake assemblages across North America is strongly associated with ecoregions and vegetation cover (R2 = 0.65 and 0.47, respectively). The close relationship with macrovegetation makes relative tail length a useful tool for predicting how snake assemblages will change as climates and biomes change across space or through time. This “ecometric” approach provides a medium-scale link between data collected from ecological studies over decades to data assembled from the fossil record over thousands, tens of thousands, or even millions of years. We show how historical vegetation changes between the early 20th and 21st centuries at five preserves in North America resulted in ecometric changes that parallel the geographic distribution of relative tail length in snake communities across North America. This file contains supplementary data: specimen data, locomotor categorizations, and super-tree phylogeny.US National Science Foundation (EAR-0843935), Integrated Climate Change Biology programme (iCCB) of the International Union of Biological Sciences (IUBS), NSF Biological Informatics Postdoctoral Fellowship to JJH (NSF 98-162, 0204082

Synopsis and taxonomic revision of three genera in the snake tribe Sonorini

Cox, Christian L., Davis Rabosky, Alison R., Holmes, Iris A., Reyes-Velasco, Jacobo, Roelke, Corey E., Smith, Eric N., Flores-Villela, Oscar, McGuire, Jimmy A., Campbell, Jonathan A. (2018): Synopsis and taxonomic revision of three genera in the snake tribe Sonorini. Journal of Natural History 52 (13-16): 945-988, DOI: 10.1080/00222933.2018.1449912, URL: http://dx.doi.org/10.1080/00222933.2018.144991

Conceptualizing communities as natural entities: a philosophical argument with basic and applied implications

Recent work has suggested that conservation efforts such as restoration ecology and invasive species eradication are largely value-driven pursuits. Concurrently, changes to global climate are forcing ecologists to consider if and how collections of species will migrate, and whether or not we should be assisting such movements. Herein, we propose a philosophical framework which addresses these issues by utilizing ecological and evolutionary interrelationships to delineate individual ecological communities. Specifically, our Evolutionary Community Concept (ECC) recognizes unique collections of species that interact and have co-evolved in a given geographic area. We argue this concept has implications for a number of contemporary global conservation issues. Specifically, our framework allows us to establish a biological and science-driven context for making decisions regarding the restoration of systems and the removal of exotic species. The ECC also has implications for how we view shifts in species assemblages due to climate change and it advances our understanding of various ecological concepts, such as resilience