The evolution of the tree of life

The tree of life is one of the most important organizing principles in biology. Updates and revisions are historically derived from improved data capture, increasingly refined models of evolution and expanded taxon sampling. Tracing the changes in the tree of life over the molecular era (1990-present) highlights the evolution of biologists' understanding of life on earth and serves as a foil placing the explosion of available data over this timeframe in context. Using current-day information, we explored the taxonomic growth captured in a tree of life through historic tree reconstruction. Data capture is now facilitating improvements in genome quality rather than expanding deep diversity, as the rate of novel phylum discovery is slowing for bacteria and archaea. Using dissimilarity metrics, the proportion of changes that each historic tree encompasses identified a diminishing influence of additional taxa on high-level topological revisions. No trees recapitulated current hypotheses for deep relationships on the tree of life, reflective of disadvantages associated with high taxon sampling and the divide-and-conquer methodologies required to analyse extremely large datasets. This work clarifies the effect of the interaction between data quality, data quantity and taxonomic diversity on our ability to construct a stable tree of life.This article is part of the discussion meeting issue 'Chance and purpose in the evolution of biospheres'.