‘Tree of life’ for 2.3 million species released
Presumably, “tree of life” is placed in quotation marks because it so little resembles a tree. Didn’t it used to be capped, as Tree of Life? 😉 The new style is probably a good sign.
The first draft of the tree of life for all 2.3 million named species of animals, plants, fungi and microbes has been released. Thousands of smaller trees have been published over the years for select branches, but this is the first time those results have been combined into a single tree. The end result is a digital resource that is available online for anyone to use or edit, much like a ‘Wikipedia’ for evolutionary relationships.
To map trees from different sources to the branches and twigs of a single supertree, one of the biggest challenges was simply accounting for the name changes, alternate names, common misspellings and abbreviations for each species. The eastern red bat, for example, is often listed under two scientific names, Lasiurus borealis and Nycteris borealis. Spiny anteaters once shared their scientific name with a group of moray eels.
“Although a massive undertaking in its own right, this draft tree of life represents only a first step,” the researchers wrote. More.
Conflicts in the Tree of Life. The synthetic tree of life is a bifurcating phylogeny (with “soft” polytomies reflecting uncertainty), but some relationships are more accurately described using reticulating networks. The Open Tree of Life contains areas with conflict (Fig. 3). For example, the monophyly of Archaea is contentious-some data-store trees indicate that eukaryotes are embedded within Archaea (18, 19) rather than a separate clade. Similarly, multiple resolutions of early diverging animal (20-23) and Eukaryotic (24-28) lineages have been proposed. Reticulations help visualize competing hypotheses, gene tree/species tree conflicts, and underlying processes, such as horizontal gene transfer (HGT), recombination, and hybridization, which have had major impacts throughout the tree of life [e.g., hybridization in diverse clades of green plants (29) and animal lineages (30), including our own (31), and HGT in bacteria and archaea (32-34)]. The graphical synthesis approach used here naturally allows for storage of conflict and non-treelike structure, enabling downstream visualization, analysis, and annotation of conflict (Fig. 3) and highlighting the need for additional work in this area.
Significance: Scientists have used gene sequences and morphological data to construct tens of thousands of evolutionary trees that describe the evolutionary history of animals, plants, and microbes. This study is the first, to our knowledge, to apply an efficient and automated process for assembling published trees into a complete tree of life. This tree and the underlying data are available to browse and download from the Internet, facilitating subsequent analyses that require evolutionary trees. The tree can be easily updated with newly published data. Our analysis of coverage not only reveals gaps in sampling and naming biodiversity but also further demonstrates that most published phylogenies are not available in digital formats that can be summarized into a tree of life.(open access) pdf – C. Hinchliff et al. Synthesis of Phylogeny and Taxonomy Into a Comprehensive Tree of Life. Proceedings of the National Academy of Sciences, 2015 DOI: 10.1073/pnas.1423041112
Bet there are plenty of surprises to come.
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