Chapter 23, Evolution of Populations Big Idea 1: The process of evolution drives the diversity and unity of life. Unit 1:Evolution Chapter 23, Evolution of Populations

23.1, Population genetics provides a foundation for studying evolution Remember populations evolve NOT individuals. Darwin’s Natural Selection was not fully appreciated with Mendel’s work in genetics, which Darwin was not aware of at the time of publication.

23.1, Population genetics provides a foundation for studying evolution Microevolution versus macroevolution Micro - is the changes in allele frequencies that occur over time within a population Example: anti-biotic resistant bacteria Macro -  is evolution on a scale of separated gene pools. Example: the evolutionary history of the horse (Equidae).

23.1, Population genetics provides a foundation for studying evolution A. The Modern Synthesis 1. Population Genetics Darwin + Mendel The study of how populations change over time. 2. Modern Synthesis Theory of evolution that integrates math, etc…Modern Synthesis is still changing today as we gain more information about evolution.

23.1, Population genetics provides a foundation for studying evolution Before we move on to “B. Gene Pools and Allele Frequencies” let have a quick review of some genetic terms we need to be fluent with for this section. Get with a partner and come up with a definition and picture for each term. Use the book as a last resort or to check your finished product. Allow yourself to struggle and access your prior biological knowledge.

23.1, Population genetics provides a foundation for studying evolution Gene pool, Chromosome, gene, allele, homozygous, heterozygous, dominant, recessive, gene flow, genetic drift, mutation, genotype, phenotype, incomplete dominance, co-dominance, gene loci (locus), gametes, zygotes. 18 Terms.

23.1, Population genetics provides a foundation for studying evolution B. Gene Pools and Allele Frequencies 1. Population – same species, same place, same time capable of interbreeding to produce fertile offspring. 2. Not all populations are isolate or have sharp boundaries. Gene Pool – all the genes at any one time in a population.

23.1, Population genetics provides a foundation for studying evolution

23.1, Population genetics provides a foundation for studying evolution Gene pool consists of all the alleles at all gene loci in all the individuals of the population. Allele frequency – is the proportion of each allele within the population. If only one allele exists at a particular locus it is said to be fixed. When there are two alleles p represents one alleles and q represent the second allele. With this information you can allele frequencies and genetic variability within a population

23.1, Population genetics provides a foundation for studying evolution C. The Hardy-Weinberg (HW) Theorem 1. Preservation of Allele Frequencies How do gene pools NOT evolve? HW describes how Mendelian inheritance preserves genetic variation from generation to the next in population that are NOT evolving. To understand how populations evolve first we will see how they DO NOT evolve.

23.1, Population genetics provides a foundation for studying evolution 2. HW equilibrium p2+2pq +q2 = 1 P2 = for example AA Pq = for example Aa Q2 = for example aa Note that p (all “A”) + q (all “a”) = 1

23.1, Population genetics provides a foundation for studying evolution Example Problem:

23.1, Population genetics provides a foundation for studying evolution 3. Conditions for Hardy Weinberg Equilibrium Extremely Large Population Size No gene flow No Mutations Random mating No Natural Selection Memorize these!!!!!!!!!!

23.1, Population genetics provides a foundation for studying evolution The sources of variation in a real population Mutation: only source for new alleles Sex Recombination Natural Selection: the primary mechanism of adaptive evolution Genetic drift: allele frequency deviation due to small population The bottleneck effect The founder effect Gene flow: the gain or loss alleles by population

23.1, Population genetics provides a foundation for studying evolution 4. Population Genetics and Human Health Used to determine APPROXIMATIONS of PKU carriers.