BIOL208 Lecture Notes - Base Pair, Alpheidae, Assortative Mating
9 Apr 2014
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Biol 208 (january 10, 2014) guest lecture: what is an executive summary, a super condensed lab report, practical skill for many professions. Review evolution: two mechanisms, natural selection. There is no random reproduction: genetic drift, evolution can change populations, creation of new species. Problems with defining species: cline (or ecocline , change in genotype and phenotype over a very broad geographical region. Post-zygotic reproductive isolation: hybrid inviability, zygote formed but organism doesn"t survive to term, hybrid sterility, organism cannot reproduce even though it has reached maturity (zero fitness) Allopatric speciation: single population that gets separated geographically over time, ex. land brigde formation between north and south america; snapping shrimp population was split by the land bridge resulted in 2 species that originated from 1 species. Assortative mating mating where there is a preference for a certain trait(s) Speciation in action: stickleback fish example, types: One type always lives in streams (stream species: smaller of the two.
