North Carolina State University
This INSPIRE award is partially funded by Sedimentary Geology and Paleobiology Program and Surface Earth Processes Section of the Earth Science Division of the Directorate for Geoscience, the Genetic Mechanisms Cluster of the Directorate for Biosciences, the Chemistry of Life Processes Program of the Directorate for Mathematical and Physical Sciences, the Cross-EF Activities Program, the Office of Multidisciplinary Activities, and the INSPIRE program.
Conventional wisdom states there is a short (>1 million years) ?life span? for original molecules. Recent recovery of both soft tissues (blood vessels and their contents, cells, flexible matrix), and component molecules indicates that under some conditions, tissues and the molecules comprising them will persist longer than proposed. During the tenure of this project, the researchers hope to demonstrate that biomolecules recovered from ancient fossils can yield information on evolutionary relationships, as well as other aspects of extinct organisms. More importantly perhaps, they will study the chemical nature of modifications to these original molecules that contribute to preservation, such as unusual cross links, or bonding to environmental chemicals; and will study which environments are most likely to yield fossils preserving this kind of information, which will benefit the field at large, because a better understanding of process and environment will expand molecular studies of fossils.
The proposed time limit on molecular preservation has limited testing of older fossils for molecular content and hindered methods development. Molecules, especially DNA and proteins, yield information on evolution, but also on the function of organisms, and perhaps on how evolution and natural selection work at the molecular level. But, to undertake this research requires an expansion of existing databases which are used for comparison. Currently, the vast majority of genomic and proteomic data are derived from humans, next from mammals. The researchers propose to generate proteomic data from non-mammalian taxa as part of this project. Additionally, existing databases do not account for modifications to molecules due to preservational processes, and thus many search algorithms will fail to identify modified molecules. The researchers will address this by conducting time-point sampling of a single taxon, and by experiments designed to approximate the natural processes that may result in molecular preservation. To understand the evolution of life, scientists have relied on morphological characters retained in fossilized elements, and both morphological and molecular data derived from extant organisms. However, in some cases, molecular studies give a different picture of evolutionary histories than do morphological features, and when these conflict, relationships are not clear. This research challenges the conventional wisdom of ~1Ma temporal limits of molecular longevity, and has the potential to extend the record of molecular evolution into deep time.
