Chapter 16 Section 1: Genetic Equilibrium

Variation of Traits In a Population Population Genetics Population Genetics –Microevolution vs. macroevolution –Range of variations –Bell curve Causes of Variation Causes of Variation –Mutation –Recombination –Random fusion of gametes

Allele Frequencies and Gene Pool Gene pool Gene pool Allele frequency Allele frequency Phenotype frequency Phenotype frequency Calculating allele frequency Calculating allele frequency –Must add up to 1 –1- freq. RR – freq. rr = freq. of Rr

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Maintaining Genetic Equilibrium – The Hardy-Weinberg Equilibrium Maintaining Genetic Equilibrium – The Hardy-Weinberg Equilibrium –No mutations –Random mating –Large population –No emmigration/immigration –No natural selection Genetic Equilibrium

Hardy-Weinberg Equation: p + q = 1  allele frequency p + q = 1  allele frequency p = freq. of A p = freq. of A q = freq. of a q = freq. of a p 2 + 2pq + q 2 = 1  phenotype frequency p 2 + 2pq + q 2 = 1  phenotype frequency p 2 = freq. of AA p 2 = freq. of AA q 2 = freq. of aa q 2 = freq. of aa 2pq = freq. of Aa 2pq = freq. of Aa

Chapter 16 Section 2: Disruption of Genetic Equilibrium

QOD What disrupts genetic equilibrium?

Disruptions to Genetic Equilkibrium Mutation Mutation Gene flow Gene flow –Immigration –Emigration Genetic drift Genetic drift Nonrandom mating Nonrandom mating –assortative mating –Sexual selection Natural Selection Natural Selection

Types of Selection Stabilizing selection Stabilizing selection Directional selection Directional selection Disruptive selection Disruptive selection

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QOD What is speciation? How does it happen?

Chapter 16 Section 3: Formation of Species

The Concept of a Species Speciation Speciation Morphological Concept of Species Morphological Concept of Species –Morphology and classification –Limitations Biological Species Concept Biological Species Concept –Fertility –Limitations

Requirements for Speciation Isolation Isolation –Gene flow Natural selection and genetic drift Natural selection and genetic drift Diverge into two distinct species Diverge into two distinct species

Isolating Mechanisms Geographic isolation Geographic isolation –Allopatric speciation Reproductive isolation Reproductive isolation –Prezygotic –Postzygotic Sympatric speciation Sympatric speciation

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Speciation Rates Gradualism Gradualism Punctuated equilibrium Punctuated equilibrium