BIOL 152 1st EditionExam # 1 Study Guide Lectures: 1 - 12Asexual Reproduction: - Single parent passes all of its genes to offspring- Offspring is a clone Sexual Reproduction: - Each parent passes half of its genes Genetic Variation (arrives by chance):1) Mutation:- Generates new variation- New alleles are formed- Somatic Mutation= occurring in the body’s tissues (only affects one cell)- Germ-line=occurring in the reproductive cells & passed onto the next generation (affects all the cells and descendants and is more important) - Harmful Mutations=Random changes to an organism - Neutral Mutations=No effect on the organism (occur in the genome that is not important)- Advantageous Mutations=Mutation that is beneficial in terms of survival or reproduction2) Recombination:- Shuffles mutations to create new combinations of mutations- New alleles are formedDarwin, Wallace, Thomas:1) Darwin:- Circumnavigation of the world in HMS Beagle- Established theory of natural selection (evolution)- “Survival of the fittest”-he concluded only those organisms that are well-suited for the environment will survive long enough to produce offspring- “Origin of Species” 18582) Alfred Wallace:- Additional information to natural selection and evolution3) Thomas Malthus- Malthus stated there was an increase in human population and not enough resources to accommodate for everyone- Darwin used this theory in his evolution theoryFitness: relative contribution an individual makes to gene pool of the next generationNatural Selection:- Allele frequencies changing from generation to generation according to the allele’s impact on the survival and reproduction of individuals- Acts on individuals because individuals have mutations occur, but with time the population evolves based on whether the mutation is harmful or beneficial. If the mutation is harmful it will have no long-term evolutionary impact. - Individuals that are best adapted to the environment are selected for- Nature selects which variation will be inherited and which will be diminishedEvolution: change in allele or genotype frequencies of a populationGenome: total genetic complement of an individual organismGene Pool: all alleles at all gene loci in all individuals of a population (species)Genetic Structure: any pattern in the genetic makeup of an individual Calculate allele and Genotype Frequencies:Hardy Weinberg Equilibrium Theorem:- Theorem states that frequencies of alleles and genotypes in a population’s gene pool remain constant from generation to generation - Non-evolving population- Hardy Weinberg Equation: p^2+2pq+q^2=1Conditions for Hardy Weinberg Equilibrium Theorem:1) No natural selection2) No gene flow (no addition or subtraction of individuals)3) No mutations4) Large population size5) Random mating*When these conditions are violated the population’s gene pool will no longer remain constantPrediction of alleles and frequencies:- When given an allele to predict the allele of the same generation it will be thesame- When population is in equilibrium frequency and allele will be the same (no change in equilibrium)- Given two different alleles and asked to decide whether the population is equilibrium compare the two and if they are different then the population is not in equilibriumForms of Natural Selection:1) Stabilizing Selection: - Acts against extreme phenotypes favoring the more common intermediate formExample: The lizards at the extreme ends of the bell-shape curve (the super dark and super light) are eaten because of the environment. The intermediate (in between dark and light) lizards are favored, making the distribution towards the middle. 2) Disruptive (Diversifying) Selection:- Variation at both extremes favored- Heterogeneous or disrupted environmentsExample: The lizards in the middle of the bell-shape curve (in between dark and light) are eaten and the super dark and super light lizards are favored by the environment3) Directional Selection:- Frequency shifted to one direction or extreme- Common during periods of environmental changesExample: If the environment favors super dark lizards then the curve will be skewed benefiting the super dark lizards and the intermediate and lightlizards will be eaten.4) Balancing Selection- Evolutionary process that maintains two versions over time - Maintenance of two or more alleles in a population5) Positive Selection: - Increases frequency of certain alleles (resulting in adaptation/increasedfitness)- May promote fixation of these alleles6) Negative Selection- Decrease frequency of harmful alleles that reduce fitnessGene Flow: - transfer of alleles between populations- Isolated populations= no gene flow- How? MigrationGenetic Drift: - Chance changes in gene pool of small populations- Lead to fixation of alleles- Reduces genetic