ABSTRACT

EAR-0541744
SCHWEITZER

The primary objectives of the proposed research are to: 1) identify and characterize soft tissues and cellular features preserved in multiple fossil specimens across time, and 2) test hypotheses concerning persistence of cellular and subcellular structure and molecular information in a variety of exceptionally preserved fossil specimens. This research addresses the following:
Hypothesis 1: Morphological soft tissue and cellular preservation may indicate preservation of informative biomolecular fragments, such as proteins or DNA.
Hypothesis 2: Organic, cellular, and molecular components within bone matrices of vertebrate tissues each degrade at different rates, and these differences can be documented by applying identical methods to fossils of varying ages.
Intellectual Merit:
Geochemical and biochemical investigations into degradation of molecular information in fossil specimens suggest a finite lifespan in fossils, limited to well under a million years. The lifespan and preservation potential of soft tissues and cellular structures, preserved with original transparency, flexibility and resilience"i.e., preserved as still soft tissues"have been predicted to be significantly less. And yet, recent research shows that they do persist. To understand how soft tissues and cells are preserved, it is necessary to characterize their present composition. Proposed immunochemical, spectroscopic and enzymatic analyses of components recovered from fossil specimens will identify molecules, which comprise tissues and cells. If primary (original to the source organism), their identification will clarify processes involved in degradation, preservation, and fossilization at the molecular and cellular levels, and reveal evolutionary and phylogenetic patterns. If no original material can be identified, the soft tissues indicate previously unknown geochemical processes resulting in resilient polymeric material retaining morphological and functional identity with original structures.
By analyzing and characterizing these remnants in fossil specimens and comparing their compositions to that of extant vertebrate vessels, cells and bone matrix, it may be possible to identify molecular source materials from the components that remain behind, and create more accurate models of degradation pathways under naturally occurring conditions. Resulting models may then be applied to identify other fossil material with potential for recovery of informative molecular remains.
Broader Impacts:
Integration of research and education: The PI currently supervises 2 PhD students, one Master's student, and two undergraduates. Beginning in fall 2005, four additional graduate students will begin research projects under her direction, all of which will have an analytical component. This proposal, if awarded, will fund their research and contribute to their learning and applying new technological approaches to the study of extinct life. In addition, the PI teaches both introductory and advanced classes in dinosaur science, and includes results from ongoing research directly into lecture material.
Broadening the participation of underrepresented groups: Four students (as of fall '05) working in the labs in the fall will be female, and two of these represent minority ethnic groups.
Dissemination of research results: Preliminary results of experiments forming the foundation of this proposal have been published in journals that are broadly interdisciplinary, and were and will be presented at several professional meetings. In addition, the overall results have reached the public via the popular media. Data acquired during the tenure of the grant will be disseminated first via peer review processes, then made available to the general population through media outlets and longer, but less technical publications. Finally, this research will be part of permanent exhibits in both the North Carolina Museum of Natural Sciences and the Museum of the Rockies, in a format appropriate for the general public, and several other programs for public dissemination through popular media formats have been discussed.

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