Tree of Life Reveals Clock-Like Speciation and Diversification

Genomic data are rapidly resolving the tree of living species calibrated to time, the timetree of life, which will provide a framework for research in diverse fields of science. Previous analyses of taxonomically restricted timetrees have found a decline in the rate of diversification in many groups of organisms, often attributed to ecological interactions among species. Here, we have synthesized a global timetree of life from 2,274 studies representing 50,632 species and examined the pattern and rate of diversification as well as the timing of speciation. We found that species diversity has been mostly expanding overall and in many smaller groups of species, and that the rate of diversification in eukaryotes…

• NS
  National Science Foundation

  Awards: 1455762, 1455761, 0850013, 1262481, 0649107, 1262440, NNA09DA76A
• NA
  National Aeronautics and Space Administration

  Award: NNA09DA76A
• UO
  University of Pennsylvania
• AS
  Arizona State University
• PS
  Pennsylvania State University
• NA
  NASA Astrobiology Institute

  Award: NNA09DA76A
• NI
  National Institutes of Health