BIO 1305 Lecture Notes - Lecture 3: Species Problem, Sympatric Speciation, Phylogenetic Tree
16 Dec 2017
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Fill out the terms and expand upon them. (giving examples, diagrams, explaining, etc. when applicable. : define species. A group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring; they do not breed successfully with members of other populations/species: reproductive isolation is the emphasis of the biological species concept. Expand upon the different ways species can become reproductively isolated. Prezygotic barriers: habit (different locations), temporal (different mating times), behavioral (mating calls/habits), mechanical ( parts don"t fit ), genetic (sperm doesn"t meet egg). Postzygotic barriers: reduced hybrid viability (cannot survive), reduced hybrid fertility (cannot reproduce), hybrid breakdown (f2 generations won"t reproduce: limitations of the biological species concept. Cannot be applied to fossils or asexual organisms. Gene flow can occur between distinct species: other species concepts. Emphasizes the unity within a species rather than the separateness. Morphological species concept: defines a species by structural features.
