Biology subjects

Pearse, W. D.

Publications and source records attributed to Pearse, W. D..

3 recordsLinked to original sources

bioRxiv2018

What we (don’t) know about global plant diversity

RationaleThe era of big biodiversity data has led to rapid, exciting advances in theoretical and applied biological, ecological and conservation sciences. While large genetic, geographic and trait databases are available, these are neither complete nor random samples of the globe. Biases in species absence in these databases create problems, reducing our inferential and predictive power.\n\nMethodsWe performed a comprehensive examination of the taxonomic and spatial sampling in the most complete current databases for plant genes, locations, and traits.\n\nResultsOnly 17.7% of the worlds described land plants feature in all three databases, meaning that more than 82% of plant biodiversity lacks representation in at least one database. Species coverage is highest for location data and lowest for genetic data. Bryophytes and orchids stand out taxonomically and the equatorial region stands out spatially as poorly represented in all databases.\n\nConclusionWe have highlighted a number of clades and regions about which we know little functionally, spatially and genetically, on which we should set research targets. The scientific community should recognize and reward the significant value, both for biodiversity science and conservation, of filling in these gaps in our knowledge of the plant tree of life.

ecology↗

bioRxiv2018

The interaction of phylogeny and community structure: linking clades’ ecological structures and trait evolution

1AimCommunity phylogenetic studies use information about species evolutionary relationships to understand the processes of community ecological assembly. A central premise of the field is that species evolution maps onto ecological patterns, and phylogeny reveals something more than species traits alone. We argue, therefore, that there is a need to better understand and model the interaction of phylogeny with species traits and community composition.\n\nInnovationWe outline a new method that identifies clades with unusual ecological structures, based around partitioning the variation of species site occupancies ({beta}-diversity). Eco-phylogenetic theory would predict that these clades should also demonstrate distinct evolutionary trajectories. We suggest that modelling the evolution of independent trait data in these clades represents a strong test of whether there is an association between species ecological structure and evolutionary history.\n\nMain conclusionsUsing an empirical dataset of mammals from around the world, we identify two clades of rodents that tend not to co-occur (are phylogenetically overdispersed), and then find independent evidence of slower rates of body mass evolution in these clades. We suggest that our approach, which assumes nothing about the mode of species trait evolution but rather seeks to explain it using ecological information, presents a new way to examine eco-phylogenetic structure.

evolutionary biology↗

bioRxiv2018

The Effect of Phylogenetic Uncertainty and Imputation on EDGE Scores

Faced with the challenge of saving as much diversity as possible given financial and time constraints, conservation biologists are increasingly prioritizing species on the basis of their overall contribution to evolutionary diversity. Metrics such as EDGE (Evolutionary Distinct and Globally Endangered) have been used to set such evolutionarily-based conservation priorities for a number of taxa, such as mammals, birds, corals, amphibians, and sharks. Each application of EDGE has required some form of correction to account for species whose position within the tree of life are unknown. Perhaps the most advanced of these corrections is phylogenetic imputation, but to date there has been no systematic assessment of both the sensitivity of EDGE scores to a phylogeny missing species, and the impact of using imputation to correct for species missing from the tree. Here we perform such an assessment, by simulating phylogenies, removing some species to make the phylogeny incomplete, imputating the position of those species, and measuring (1) how robust ED scores are for the species that are not removed and (2) how accurate the ED scores are for those removed and then imputed. We find that the EDGE ranking for species on a tree is remarkably robust to missing species from that tree, but that phylogenetic imputation for missing species, while unbiased, does not accurately reconstruct species evolutionary distinctiveness. On the basis of these results, we provide clear guidance for EDGE scoring in the face of phylogenetic uncertainty.

zoology↗