huelsenbeck11notes

huelsenbeck11notes - Lecture 11 Monday, March 30, 2009...

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Lecture 11 Monday, March 30, 2009 Macroevolution and microevolution Microevolution is the process of change in individual species. Macroevolution is evolutionary change above the species level, including the formation of species, the diversification of species, and the appearance of major evolutionary developments. One of the important questions in evolutionary biology is how well macroevolutionary patterns can be predicted from our understanding of microevolution. The punctuated equilibrium theory Pattern: The punctuated equilibrium theory is a generalization about the pattern of evolution as seen in the fossil record. The pattern is the stasis of established wide-spread lineages and morphological change when new species appear. The two are compared in Fig. 24.13. What is not seen very often in the fossil record is gradual and continuous change in widespread species. Darwin’s explanation for not seeing this pattern was the imperfection of the fossil record. Even when the fossil record of some groups is more complete, the punctuated equilibrium pattern instead of a gradual pattern is often found. The fossil record of humans and their immediate ancestors, which
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huelsenbeck11notes - Lecture 11 Monday, March 30, 2009...

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