ANTH 1102 Lecture Notes - Lecture 2: Species Problem, Ecological Niche, Cladogenesis
4 Mar 2017
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Document Summary
Macroevolution : how new species & higher taxa are created; accumulation of the effects of microevolution. Biological species concept : a species is a population whose members have the potential to interbreed & produce offspring, but cannot produce offspring with other species: based on inter-fertility (not physical similarities) Ecological species concept : emphasizes role of natural selection in maintaining species boundaries i: species de ned by their use of environmental resources (their ecological niche) Result of genetic factors that cause offspring to rely upon resources not previously used. Ex. competition for food leads to need for new food source. Reduced hybrid viability : abort development of hybrid at some embryonic stage. Reduce hybrid fertility : meiosis doesn"t produce fertile gametes in vigorous hybrid (ex. mule is a sterile hybrid) Richard owen > saw similarities in morphological traits among different species and recognized patterns of similarity that can form hierarchy in evolution.
