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The Hardy-Weinberg Principle. Modern biologists’ definition of “evolution”. = the change in genetic makeup (or gene pool ) of a population over time. What’s a gene pool?. = the frequency of each of the alleles within a population. Hardy & Weinberg (two mathematicians).
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Modern biologists’ definition of “evolution” = the change in genetic makeup (or gene pool) of a population over time. What’s a gene pool? = the frequency of each of the alleles within a population.
Hardy & Weinberg (two mathematicians) • Developed the Hardy-Weinberg Principle in large populations in which only random chance is at work, allele frequencies are expected to remain constant from generation to generation. G.H. Hardy Wilhelm Weinberg
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What causes evolutionary change? Any of the following 5 factors that cause a change in the allele frequencies: 1) Natural selection – favours the passing on of some (advantageous) alleles over others. 2) Small population size – increases likelihood of genetic drift. 3) Mutation – introduces new alleles to a population. 4) Immigration or Emigration – introduces or removes alleles in a population 5) Horizontal gene transfer – the gaining of new alleles from a different species (i.e. Conjugation in bacteria).