TimeTree is a free public database developed by S. Blair Hedges and Sudhir Kumar, now at

Temple University Temple University (Temple or TU) is a public university, public Commonwealth System of Higher Education, state-related research university in Philadelphia, Philadelphia, Pennsylvania, United States. It was founded in 1884 by the Baptist ministe ...

, for presenting times of divergence in the

tree of life The tree of life is a fundamental archetype in many of the world's mythology, mythological, religion, religious, and philosophy, philosophical traditions. It is closely related to the concept of the sacred tree.Giovino, Mariana (2007). ''The ...

. The basic concept has been to produce and present a community consensus of the

timetree TimeTree is a free public database developed by Stephen Blair Hedges, S. Blair Hedges and Sudhir Kumar, now at Temple University, for presenting times of divergence in the Tree of life (biology), tree of life. The basic concept has been to produce ...

of life from published studies, and allow easy access to that information on the web or mobile device. The database permits searching for average node times between two

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

or higher taxa, viewing a timeline from the perspective of a taxon, which shows all divergences back to the origin of life, and building a

of a chosen taxon or user-submitted group of taxa. TimeTree has been used in public education to conceptualize the evolution of life, such as in high school settings. David Attenborough's Emmy Award-winning film and television program Rise of Animals used Hedges and Kumar's circular

of life, generated from the TimeTree database, as a framework for the production. The

was brought to life using animated computer-generated imagery in scenes every 10 minutes during the 2-hour movie. The original development of TimeTree, by Hedges and Kumar, dates to the late 1990s, with initial support from NASA Astrobiology Institute. Since then, it has been supported by additional grants from NASA, and by NSF and NIH. The current version (v5) was released in 2022 and contains data from 4,075 studies and 137,306 species.

Features

TimeTree users can search for the names of two species, such as cat and dog, to obtain the mean and median time estimates for their divergence, in millions of years. The results also show all individual time estimates, from each study, next to a geologic timescale, indicating geologic periods. Different aspects of the Earth's environment are shown next to the timescale for comparison, including Earth impacts, solar luminosity, carbon dioxide levels, and oxygen levels. Separately, a table lists the time estimates, downloadable as a spreadsheet, from each study along with references and links to the abstracts of the original articles. Users can download the original study data as

Newick Newick is a village, civil parish and electoral ward in the Lewes District of East Sussex, England. It is located on the A272 road east of Haywards Heath. The parish church, St. Mary's, dates mainly from the Victorian era, but still has a No ...

-formatted timetrees for further research. In the timeline search, users type the name of a taxon, and all divergences back to the origin of life are show with their taxon names, in a vertical ladder-like figure. Timepanels of Earth's environment also are shown next to the geological timescale, as in all three search options. The third search option,

search, involves building a

by either specifying a taxon (group) name or uploading a list of species or other taxa. After specifying a group name, the user can choose which taxonomic level they prefer to view. For example, with a family group name, either a species-level or genus-level timetree can be selected. Then, the

is show and can be output as a

file or image for publication. Times on the tree can be explored by clicking on nodes, and obtaining tables of data pertaining to the node. The database also allows search of

articles by author name. The entire open-access book ''Timetree of Life'' is presented on the site.

References

External links

* {{Official website Bioinformatics software