A primary aim of microbial ecology is to determine patterns and drivers of community distribution, interaction, and assembly amidst complexity and uncertainty. Microbial community composition has been shown to change across gradients of environment, geographic distance, salinity, temperature, oxygen, nutrients, pH, day length, and biotic factors 1-6 . These patterns have been identified mostly by focusing on one sample type and region at a time, with insights extra polated across environments and geography to produce generalized principles. To assess how microbes are distributed across environments globally-or whether microbial community dynamics follow funda mental ecological 'laws' at a planetary scale-requires either a massive monolithic cross environment survey or a practical methodology for coordinating many independent surveys. New studies of microbial environments are rapidly accumulating; however, our ability to extract meaningful information from across datasets is outstripped by the rate of data generation. Previous meta analyses have suggested robust gen eral trends in community composition, including the importance of salinity 1 and animal association 2 . These findings, although derived from relatively small and uncontrolled sample sets, support the util ity of meta analysis to reveal basic patterns of microbial diversity and suggest that a scalable and accessible analytical framework is needed.The Earth Microbiome Project (EMP, http://www.earthmicrobiome. org) was founded in 2010 to sample the Earth's microbial communities at an unprecedented scale in order to advance our understanding of the organizing biogeographic principles that govern microbial commu nity structure 7,8 . We recognized that open and collaborative science, including scientific crowdsourcing and standardized methods 8 , would help to reduce technical variation among individual studies, which can overwhelm biological variation and make general trends difficult to detect 9 . Comprising around 100 studies, over half of which have yielded peer reviewed publications (Supplementary Table 1), the EMP has now dwarfed by 100 fold the sampling and sequencing depth of earlier meta analysis efforts 1,2 ; concurrently, powerful analysis tools have been developed, opening a new and larger window into the distri bution of microbial diversity on Earth. In establishing a scalable frame work to catalogue microbiota globally, we provide both a resource for the exploration of myriad questions and a starting point for the guided acquisition of new data to answer them. As an example of using this Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of r...
Herbivory has evolved in many groups of vertebrates, but it is rare among both extinct and extant nonavian reptiles. Among squamate reptiles, (lizards, snakes, and their relatives), <2% of the >7,800 species are considered to be herbivorous, and herbivory is restricted to lizards. Here, we show that within a group of South American lizards (Liolaemidae, Ϸ170 species), herbivory has evolved more frequently than in all other squamates combined and at a rate estimated to be >65 times faster. Furthermore, in contrast to other herbivorous lizards and to existing theory, most herbivorous liolaemids are small bodied and live in cool climates. Herbivory is generally thought to evolve only in reptile species that are large bodied, live in warm climates, and maintain high body temperatures. These three well known ''rules'' of herbivory are considered to form the bases of physiological constraints that explain the paucity of herbivorous reptile species. We suggest that the recurrent and paradoxical evolution of herbivory in liolaemids is explained by a combination of environmental conditions (promoting independent origins of herbivory in isolated cool-climate regions), ecophysiological constraints (requiring small body size in cool climates, yet high body temperatures for herbivores), and phylogenetic history. More generally, our study demonstrates how integrating information from ecophysiology and phylogeny can help to explain macroevolutionary trends.ecophysiology ͉ macroevolution
We tested for the occurrence of Bergmann's rule, the pattern of increasing body size with latitude, and Rapoport's rule, the positive relationship between geographical range size and latitude, in 34 lineages of Liolaemus lizards that occupy arid regions of the Andean foothills. We tested the climatic‐variability hypothesis (CVH) by examining the relationship between thermal tolerance breadth and distribution. Each of these analyses was performed varying the level of phylogenetic inclusiveness. Bergmann's rule and the CVH were supported, but Rapoport's rule was not. More variance in the data for Bergmann's rule and the CVH was explained using species belonging to the L. boulengeri series rather than all species, and inclusion of multiple outgroups tended to obscure these macroecological patterns. Evidence for Bergmann's rule and the predicted patterns from the CVH remained after application of phylogenetic comparative methods, indicating a greater role of ecological processes rather than phylogeny in shaping the current species distributions of these lizards.
We provide a critical review of a recent taxonomic revision of Chilean Liolaemus lizards (Iguania: Liolaemidae) by Pincheira-Donoso and Núñez (2005) and a recent paper (PincheiraDonoso et al. 2008), which proposed several new taxonomic and phylogenetic arrangements. We document fundamental problems with many of the proposed taxonomic revisions in both publications, which if followed, could lead to serious taxonomic confusion. In Pincheira-Donoso and Núñez (2005) a subgeneric classification is erected, which was produced by outdated methods (phenetic analyses), cannot be replicated (no matrix is presented), and is taxonomically untenable (some of the subgenera are nested within other subgenera). Most of the taxonomic groups that are proposed have been previously proposed, albeit differently constituted, yet often previous research is not given attribution; when findings are different, the research of others is either overlooked or dismissed without comment. The diagnoses of species and subspecies (including several newly proposed taxa) are often written in an authoritative manner (without supporting data or information), making them insufficient for distinguishing the focal taxon from others belonging to the same group, finally leading to uncertainty regarding the validity of several of the newly proposed taxa, combinations, or synonymies. We also describe less egregious errors of omission and commission. In Pincheira-Donoso et al. (2008), most of the proposals follow the Pincheira-Donoso and Núñez (2005) revisions, some species are allocated to groups without consistent cladistic support and other proposed relationships are based on incomplete evidence from other studies dismissing the limitations of the arrangement. Critical species are not identified in a list of material examined. Finally, Pincheira-Donoso et al. (2008) present a somewhat outdated and biased discussion of the relative value of using molecules or morphology in systematics. In light of these limitations, and in an effort to stabilize and prevent further taxonomic confusion, we provide an updated phylogenetic classification of the currently recognized lizards of the family Liolaemidae (Ctenoblepharys, Liolaemus, and Phymaturus), which is based on a consensus of studies published since the first phylogenetic major revision of the clade in 1995.
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