The fields of paleontology and developmental biology contribute the significant element of time to evolutionary theory. Though these timescales differ greatly, the integration of these disciplines is key to understanding mechanisms of morphologic expression and evolutionary change. Paleontological data, especially fossil collections,provide our only direct evidence of past biodiversity and how individual species, communities, and ecosystems respond to environmental change on evolutionary and long-term ecological timescales. The development of proxies and models for predicting environmental or genetic stress associated with extinction is a major research challenge and has important economic and societal implications. The European cave bear, Ursus spelaeus, was part of the Pleistocene megafauna that went extinct during the Last Glacial Maximum. Why the cave bear went extinct, whereas other bears such as the brown bear did not, has been a central question in evolutionary biology. In our study of the evolution and development of the dentition in bears, we try to understand not only morphological variation, but also extinction. The shape of the mammalian dentition, which is determined prior to eruption and modified only by wear, is strongly correlated with diet. Tooth shape can be described by the patterns of cusps that compose the crown, or chewing surface, of the tooth. We use a metric called dental complexity to reconstruct the diet of cave bears and develop a system whereby dental variation can be measured as an indicator of environmental and genetic stress in a population.
|Tila||Julkaistu - 2016|