Welcome to the DateLife project. It is a service for getting chronograms (trees with branch lengths proportional to time) using information from published chronograms (which are ideally based on robust other information, such as fossil calibrations). It can do this from a list of taxa or for an input phylogeny. Note that this approach is inferior to doing a thorough analysis using your own raw sequences or trees and carefully checked calibration points, ideally with appropriate uncertainty: this can be done with tools like BEAST, r8s, RevBayes, treePL, PATHd8, and many more. However, DateLife can be useful for cases where meeting the gold standard is infeasible (arguably for some scientific studies) or overkill (i.e., for crediting students in a field-based taxonomy course for the amount of time represented by their specimens, rather than the number of, say, families). DateLife has multiple components, all of them open:
  • An R package, datelife for doing the calculations. If you're an R user, this is probably the way to go. It can be installed by first installing the devtools package from CRAN and then doing devtools::install_github("phylotastic/datelife").
  • The current website: go to here to make a query.
  • Using the API to call this service from another tool.

DateLife is the beneficiary of much work:
  • The late National Evolutionary Synthesis Center (NESCent), which sponsored hackathons that led to initial work on this project.
  • The Open Tree of Life project that provides the open, metadata rich repository of trees used for DateLife.
  • The many scientists who publish their chronograms in an open, reusable form, and the scientists who curate them for deposition in OpenTree.
  • The rotl, ape, and geiger packages used to gather, process, and present information.
  • The US National Science Foundation (NSF) for funding nearly all the above, in addition to the ABI grant that funded this project itself.
  • RStudio's Shiny Server and shiny package open infrastructure.
  • Docker.

Note source code is available at https://github.com/phylotastic/datelife (the R package with this functionality), https://github.com/phylotastic/datelifeweb (the package that generates the web page), and https://github.com/phylotastic/datelifedocker (the docker file to create the image).


DateLife is part of the Phylotastic project, funded by NSF. It uses resources from the Open Tree of Life project, rOpenSci, and TreeBase. To help, please add trees to OpenTree's database! [they can be yours or others']