BIOL240 Lecture Notes - Lecture 13: Sympatric Speciation, Allopatric Speciation, Allele Frequency
13 Feb 2018
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Define the terms species and speciation. (section 22. 1) Explain how genetic isolation maintains the integrity of species. (section 22. 2 & 22. 3: list and describe pre- and post-zygotic reproductive barriers, explain the terms allopatric speciation and sympatric speciation. Define sexual selection and explain how it differs from natural selection. (section 21. 4) The evolution of populations - the smallest unit of evolution: only populations evolve, microevolution is a change in allele frequencies in a population over generations. Mutation and sexual reproduction produce the genetic variation that makes evolution possible. Genetic variation: variation in individual genotype leads to variation in individual phenotype, natural selection can only act on existing genetic variation. Variation within a population: population geneticists measure polymorphisms in a population by determining the amount of heterozygosity at the gene and molecular levels, average heterozygosity measures the average percent of loci that are heterozygous in a population. Mutation: mutations cause new genes and alleles to arise.
