Notice: This is an archived and unmaintained page. For current information, please browse

2013 Annual Science Report

Pennsylvania State University Reporting  |  SEP 2012 – AUG 2013

Biosignatures of Ancient Rocks - Hedges Group

Project Summary

Our work involves the design, assembly, and release to the public of a tree of life calibrated to geologic time (timetree). It is needed by astrobiologists to help determine the source of biomarkers for the presence of life in the geologic record.

4 Institutions
3 Teams
0 Publications
0 Field Sites
Field Sites

Project Progress

The NAI research of Blair Hedges mainly concerns the refinement of the tree of life scaled to geologic time (i.e., the timetree of life). This information helps to relate chemical and geological biomarkers in the rock record to organisms that may have produced those biomarkers. In turn this provides a better understanding of biosphere evolution, and identifying possibly universal mechanisms and pathways applicable to life on other planets. In early 2009 the Hedges lab produced 12 publications bearing on this goal, including an edited book covering all of life down to the family level (S. B. Hedges & S. Kumar, The Timetree of Life, Oxford U Press). Since then, we have focused efforts on building a timetree of life to the species level, with tens of thousands of species from 2,400 studies assembled in our database. That work has been completed and is being prepared for publication. TimeTree receives >1000 searches per day and is used as a teaching tool in high schools.