2000 Annual Science Report
Harvard University Reporting | JUL 1999 – JUN 2000
Molecular Paleontology and the Stratigraphic Record
Molecular clocks have become a powerful way of calibrating major evolutionary events
with the geological record, thus providing the temporal context needed for establishing
links between bursts of evolutionary innovation, along with both geological and environmental events. This is especially important in the Precambrian given the dearth of
However, when molecular clocks have been used to estimate divergence times for
groups that have good fossil records, the estimates are typically much older than a literal reading of the fossil record would suggest. It is currently unclear which type of
data is giving the better answer.
I continue to work on and develop (with important collaborations) new methods for
quantifying the incompleteness of the fossil record in the attempt to reconcile the different temporal frameworks that fossil and molecular data currently yield. The long term goal is to provide a rigorous enough temporal framework, using both molecular and fossil data, for understanding how planetary evolution affects or controls biological evolution.
PROJECT MEMBERS:Charles Marshall
RELATED OBJECTIVES:Objective 4.0
Expand and interpret the genomic database of a select group of key microorganisms in order to reveal the history and dynamics of evolution.
Describe the sequences of causes and effects associated with the development of Earth's early biosphere and the global environment.