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

古生物地理学是研究过去生物分布的学科。这是一门充满活力的学科，它使我们对地球生物群的进化和分布的理解得到了广泛的发展。泥盆纪（约4.15 - 3.6亿年前）是一个独特的古生物地理时期，经历了广泛的生物地理和进化变化。然而，泥盆纪古生物地理划分在很大程度上是通过定性分析建立的，这种定性分析完全依赖于对不同地区生物群的主观比较。虽然定性结果提供了有关海洋生物全球分布格局的有用和重要信息，但定性结论的主观性不应被忽视。此外，定性分析所依据的数据也需要更新。为了消除定性分析的偏差，更客观地评价泥盆纪古地理格局，本文将采用以下定量方法进行泥盆纪古地理分析：1)相似性分析；2)概率分析；3)地方性简约性分析。通过对马尼托巴和其他地区腕足动物的研究，这些定量分析有望提供北美泥盆纪不同时期的古生物地理框架（作为短期目标）和世界范围内的古生物地理框架（作为长期目标）。认识泥盆纪的古生物地理动态、动物进化、环境变化和生物多样性变化之间的关系，对现代保护生物学也具有潜在的意义。从早到晚泥盆纪的地方性/地方性变化与晚泥盆纪生物多样性的巨大损失之间的联系及其背后的原因应该为我们如何保护当今的生物多样性提供重要的线索，因为过去可能是未来的关键。当人类面临着越来越严重的物种灭绝时，这一点尤为重要。

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.