Paleobiogeography and faunal evolution: study of devonian brachiopods from Manitoba and paleobiogeography of North America

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Paleobiogeography is the study of the distributions of organisms in the past. It is a dynamic discipline that has led to extensive growth in our understanding of the evolution and distribution of the Earth's biota through time. The Devonian (~415-360 million years ago) was a paleobiogeographically unique period that encompassed a time of extensive biogeographic and evolutionary change. However, the Devonian paleobiogeographic divisions have been established largely through qualitative analyses that rely entirely on subjective comparisons of biota from different regions. While the qualitative results provide useful and important information about the worldwide distribution pattern of marine organisms, the subjectivity of the qualitative conclusions should not be overlooked.  Moreover, the data on which the qualitative analysis was based are in need of updating.  To eliminate the potential bias of qualitative analysis, and to evaluate the paleobiogeographic patterns more objectively with the modern updated data, the following quantitative approaches will be used to analyze Devonian paleobiogeography: 1) similarity analysis; 2) probabilistic analysis; and 3) parsimony analysis of endemicity.  With the study of brachiopods from Manitoba and other regions, these quantitative analyses are expected to provide paleobiogeographic frameworks of different intervals of the Devonian of North America (as the short-term objective) and worldwide (as the long term objective). Knowledge of the relationship between the paleobiogeographic dynamics, faunal evolution, environmental changes, and the change in biodiversity during Devonian has potential significance in modern conservation biology as well.  The connection between the change of provincialism/endemism from Early to Late Devonian and the great biodiversity loss in Late Devonian and the cause(s) underlying should give us important clues about how we can/should preserve present day biodiversity, as the past can be the key to the future. This is of particular significance when humans are encountering more and more dramatic losses of species nowadays.