Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Evolution change in frequencies of alleles in the gene pool; e.g., Allele frequencies in parents: B = .92 and b = .08; in their offspring B= .90 and b = .10 Charles Darwin British Naturalist 1809 -1882 I have called this principle, by which each slight variation, if useful, is preserved, by the term Natural Selection. Hardy-Weinberg Equilibrium Model & The Paradox Through mathematical modeling, they concluded that gene pool frequencies are inherently stable but that evolution should be expected in all populations virtually all of the time. Five Conditions No mutation No natural selection Population is infinitely large All mating is random No migration [All members breed and everyone produces equal numbers of offspring] 1 Mechanisms of Evolution Mutation Natural selection Genetic drift Non-random mating Migration ”I have called this principle, by which each slight variation, if useful, is preserved, by the term Natural Selection.” (Darwin) Hardy-Weinberg Equilibrium Equation p2 + 2pq + q2 = 1 p = frequency of dominant allele q = frequency of recessive allele Another way to collocate allele frequencies p = AA + 1/2 Aa q = aa + 1/2Aa p+q=1 p=1–q q = 1- p 2 (p + q) 2 = 1 p2 + 2pq + q2 p2 = AA 2pq = Aa q2 = aa Albinism Homozygous recessive (aa) 1/20,000 q2 = 1/20,000 = .00005 q = .007 p=1-q p = 1 - .007 p = .993 p2 + 2pq + q2 = 1 (.993) 2 + 2 (.993)(.007) + (.007) 2 = 1 .98605 + .01399 + .00005 = 1 3 Further Calculations p2 = (AA) = .98605 = 98.6% 2pq = (Aa) = .01399 = 1.4% q2 = (aa) = .00005 = .005% (the albinos) PTC Taste Testing Phenylthiocarbamide Phenylthiourea Tasters: TT or Tt Non-taters = tt Evolutionary Implications thyroid disease non-tasters more prevalent among hypothyroid patients non-tasters more susceptible to nonendemic nodular goitre tasters have a lower incidence of dental caries 4