Bio 3400 1nd Edition Lecture 14 Outline of Last Lecture Selection Experiments Mice and wheel running Other selection experiments Endler s guppies Comparison of real organisms with predictions of theoretical models Outline of Current Lecture I Waterslider selection II Detecting selection at the molecular level III Types of Mutations IV Three spined sticklebacks Current Lecture I II III Measuring Selection on Body Size of Watersliders a Preziosi and Fairbairn tracked waterstriders in streams in Quebec b Mark recapture i Survival to reproduction ii Reproductive longevity c Temporary stream enclosures i Daily reproductive success d Stabilizing selection on body size i Females larger means higher daily reproductive success and lower reproductive longevity ii Males larger means higher daily reproductive success and lower reproductive longevity iii there is natural selection on body size components in males and females and the pattern of selection matches the pattern of sexual size dimorphism Detecting Selection at the Molecular Level i Evolution change in allele frequencies ii Major forces of evolution selection genetic drift gene flow Expected Patterns of Molecular Evolution from Genetic Drift i The rate of substitution per base pair per generation the rate of mutation ii Genetic drift constant rate of substitution that is equal to the mutation These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute IV V rate iii Selection rapid loss deleterious mutation or rapid fixation beneficial mutation Types of Mutations i Synonymous no change in amino acid ii Nonsynonymous change in amino acid iii dN dS 1 substitutions are deleterious iv dN dS 1 subs are natural v dN dS 1 subs are beneficial Three Spined sticklebacks a 12 00 years ago b marine sticklebacks invaded new freshwater lakes c independent invasions into hundreds of lake d parallel morphological changes in lake populations e freshwater versus marine habitat i reduced predation by birds and fish ii increased predation by aquatic insects iii increased prey availability in benthic zone f Schluter et al i Identify one of the genes contributing to armor ii Show different alleles are associated with different environments iii Perform a new introduction into freshwater ponds iv Measure selection on the armor gene g Eda locus i Individuals with the low armor allele have higher growth rates and higher survival later in development ii Lower survival early in life
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