Degree Year


Document Type

Thesis - Open Access

Degree Name

Bachelor of Arts




Mary L. Droser


Middle Ordovician Rugosa, Eastern North America, New York, Ohio, Kentucky, Organisms, Fossil


Our understanding of the structure and function of biological systems can be increased when viewed in the context of their evolutionary history on a geological time scale. Generally, both paleoecology and ecology have focused on the interrelationships of organisms and their environments in short time frames. For instance, a paleoecologist might study the fossil communities of the Columbus Limestone reefal environment at Marblehead, Ohio, or an ecologist might attempt to characterize the interrelationship of glacier lilies and their pollinators. Both workers may realize that the organisms they study evolved in response to ecological pressures, yet neither, most likely, considers that the ecological contexts in which those organisms evolved may have changed through geologic time. Because biological systems evolve through geologic time, organisms show adaptations to conditions that mayor may not exist at the time they live but that must have directed the evolution of the organisms which gave rise to them. It is always the case that the ecology of extant organisms is, in part, a relict of their evolutionary histories. By considering organisms in the context of their evolutionary paleoecology, we can gain a powerful tool for understanding why they have evolved the way they have.

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Geology Commons