Content Objective: Students will comprehend the complexities of genetic variation in populations, including the concept of gene pools, allele frequencies in isolated populations, and the impact of natural selection on allele frequencies. They will also differentiate between types of selection (directional, disruptive, stabilizing) and apply the Hardy-Weinberg equation to understand genetic equilibrium and the factors affecting it.
Language Objective: Students will effectively communicate the principles of evolutionary genetics using specific biological terminology, including the concepts of gene pools, allele frequencies, and natural selection. They will demonstrate proficiency in explaining and calculating genetic variations and equilibriums using the Hardy-Weinberg equation in both written and oral forms.
Syllabus Details:
D4.1.9 (HL)—Concept of the gene pool. "A gene pool consists of all the genes and their different alleles, present in a population."
D4.1.10 (HL)—Allele frequencies of geographically isolated populations
D4.1.11 (HL)—Changes in allele frequency in the gene pool as a consequence of natural selection between individuals according to differences in their heritable traits. "Darwin developed the theory of evolution by natural selection. Biologists subsequently integrated genetics with natural selection in what is now known as neo-Darwinism."
D4.1.12 (HL)—Differences between directional, disruptive and stabilizing selection. "Students should be aware that all three types result in a change in allele frequency."
D4.1.13—(HL) Hardy–Weinberg equation and calculations of allele or phenotypic frequencies. "Use p and q to denote the two allele frequencies. Students should understand that p + q = 1 so genotype frequencies are predicted by the Hardy–Weinberg equation: p^2 + 2pq + q^2 = 1. If one of the genotype frequencies is known, the allele frequencies can be calculated using the same equations."
D4.1.14 (HL)—Hardy–Weinberg conditions that must be maintained for a population to be in genetic equilibrium. "Students should understand that if genotype frequencies in a population do not fit the Hardy–Weinberg equation, this indicates that one or more of the conditions is not being met, for example, mating is nonrandom or survival rates vary between genotypes."
Activity 3 - Practice Problems
A. Strengthen Your Skills
B. Expand Your Knowledge