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Many evolutionary theories make predictions about the order and timing of character evolution, and inferring ancestral states is considered a powerful tool for testing these The most common method of inference is maximum par-simony (MP; see Maddison and Maddison, 1992, and references therein). Although MP may offer reasonable estimates of ancestors for(More)
Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence. The plausibility of a(More)
Biodiversity has been described as the ‘biology of numbers and difference’ (Gaston 1996). Because species are different from one another, traditional metrics of biodiversity such as species richness or evenness increase when there are more species or when abundance is more equally apportioned among these species (see Chapters 4 and 5). Not only are species(More)
BACKGROUND Categories of imperilment like the global IUCN Red List have been transformed to probabilities of extinction and used to rank species by the amount of imperiled evolutionary history they represent (e.g. by the Edge of Existence programme). We investigate the stability of such lists when ranks are converted to probabilities of extinction under(More)
Continuously varying traits such as body size or gene expression level evolve during the history of species or gene lineages. To test hypotheses about the evolution of such traits, the maximum likelihood (ML) method is often used. Here we introduce CoMET (Continuous-character Model Evaluation and Testing), which is module for Mesquite that automates(More)
The relationships among the majority of the subgroups in the Drosophila melanogaster species group remain unresolved. We present a 2223basepair dataset for mitochondrial cytochrome oxidase I and cytochrome oxidase II for 43 species (including new data from 11 species), sampled to include the major subgroups. After a brief review of competing hypotheses for(More)
The phylogenetic relationships of several hominin species remain controversial. Two methodological issues contribute to the uncertainty-use of partial, inconsistent datasets and reliance on phylogenetic methods that are ill-suited to testing competing hypotheses. Here, we report a study designed to overcome these issues. We first compiled a supermatrix of(More)
Species diversity within communities and genetic diversity within species are two fundamental levels of biodiversity. Positive relationships between species richness and within-species genetic diversity have recently been documented across natural and semi-natural habitat islands, leading Vellend to suggest a novel macro-ecological pattern termed the(More)
Anthropogenic activities have increased the rate of biological extinction many-fold. Recent empirical studies suggest that projected extinction may lead to extensive loss to the Tree of Life, much more than if extinction were random. One suggested cause is that extinction risk is heritable (phylogenetically patterned), such that entire higher groups will be(More)
Global climate shifts and ecological flexibility are two major factors that may affect rates of speciation and extinction across clades. Here, we connect past climate to changes in diet and diversification dynamics of ruminant mammals. Using novel versions of Multi-State Speciation and Extinction models, we explore the most likely scenarios for evolutionary(More)