tion, and diversity of fossil biotas can now be used as measures of the biotic response to environmental change, rather than indicators of both the change and the response.

  • An increasing number of ecologically valuable metrics can now be evaluated confidently, either using the conventional fossil record of preserved individuals, or using various chemical proxies of former biological populations (biomarkers, isotopic signatures).

  • Relative and absolute age dating of geologic materials and time series has improved greatly in the last 20 years, and has crossed a key threshold with respect to analyzing ecological dynamics. Resolution now matches or exceeds what would be possible using conventional biostratigraphic methods, liberating geohistorical analysis of ecological dynamics from pitfalls of circularity in age and rate determinations.

  • New database and web technologies have stimulated community-based efforts to assemble and analyze large amounts of ecological, paleoecological, and evolutionary data relevant to understanding the geologic record of ecological dynamics. Such efforts at synthesis are essential partners in efforts to acquire new data.

The geologic column provides a wealth of geohistorical records that are ready to yield important data on ecological dynamics. It is not the record that is inadequate but rather the availability of resources to extract and analyze the record. Using geohistorical records to their fullest potential will require an effort focused on the biological analysis of groups known to have reasonable fossil records, and on the development of proxy methods for groups of great biological interest but poor fossilization potential. Biologists and earth scientists, working together, will need to frame research questions so that the answers take maximum advantage of the great potential of geohistorical analysis to provide major insights.



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