Comprehensive Tree Of Life Research Articles

Nurturing a sustainable Open Tree of Life

The Open Tree of Life project is a collaborative effort to synthesize, share and update a comprehensive tree of life Fig. 1. We have completed a draft synthesis of a tree summarizing digitally available taxonomic and phylogenetic knowledge for all 2.6 million named species, available at tree.opentreeoflife.org Hinchliff et al. 2015. . . This tree provides ready access to phylogenetic information which can link together biodiversity data on the basis of what we know about relevant evolutionary history. Both the unified reference taxonomy Rees and Cranston 2017 and the published phylogenetic statements underlying the tree McTavish et al. 2015 are available and accessible online. Taxa in the phylogenies are mapped to the the reference taxonomy, which aligns Open Tree taxon identifiers to those from NCBI and GBIF, among several other taxonomy resources. The synthesis tree is revised as new data become available, and captures conflict and consensus across different published phylogenetic estimates. This undertaking requires both development of novel infrastructure and analysis tools, as well as community engagement with the Open Tree of Life project. I will discuss the challenges in and the progress towards achieving these goals.

First comprehensive tree of life shows how related you are to millions of species

First comprehensive tree of life shows how related you are to millions of species

Combining Phylogenomics and Fossils in Higher-Level Squamate Reptile Phylogeny: Molecular Data Change the Placement of Fossil Taxa

Molecular data offer great potential to resolve the phylogeny of living taxa but can molecular data improve our understanding of relationships of fossil taxa? Simulations suggest that this is possible, but few empirical examples have demonstrated the ability of molecular data to change the placement of fossil taxa. We offer such an example here. We analyze the placement of snakes among squamate reptiles, combining published morphological data (363 characters) and new DNA sequence data (15,794 characters, 22 nuclear loci) for 45 living and 19 fossil taxa. We find several intriguing results. First, some fossil taxa undergo major changes in their phylogenetic position when molecular data are added. Second, most fossil taxa are placed with strong support in the expected clades by the combined data Bayesian analyses, despite each having >98% missing cells and despite recent suggestions that extensive missing data are problematic for Bayesian phylogenetics. Third, morphological data can change the placement of living taxa in combined analyses, even when there is an overwhelming majority of molecular characters. Finally, we find strong but apparently misleading signal in the morphological data, seemingly associated with a burrowing lifestyle in snakes, amphisbaenians, and dibamids. Overall, our results suggest promise for an integrated and comprehensive Tree of Life by combining molecular and morphological data for living and fossil taxa.