Understanding Population Genetics and Natural Selection Dynamics
School
Michigan State University**We aren't endorsed by this school
Course
BS 162
Subject
Biology
Date
Dec 10, 2024
Pages
4
Uploaded by ProfHeatHamster42
Q1. Draw a population where p = 0.7 and q = 0.3●Next, randomly select/circle 5 individuals to reproduce and pass on their genes tothe next generation.●Ignore sexual reproduction for the sake of this example – pretend theseindividuals pass on the exact same alleles and produce two identical offspringeach.●What is p and q for the second generation?p = 0.55, and q = 0.45Q2. How do you draw a frequency graph?●Let’s imagine we measure the hand size of all the people in class, from tip ofthumb to tip of pinky.●How would you draw a graph that shows the frequency of all those hand sizes?The x axis would be labeled hand size intervals: 10-12 cm, 12-14 cm, 14-16cm,etc. Y axis would be labeled frequency: number of people in each size range.●Discuss with your group members.●Note: “Time” Should not be on the x axisQ3. Draw two frequency graphs of moth populations – one before and oneafter the Industrial Revolution.Q4. Given this data are you going to see directional selection in humanbirth weight? If not, what would you expect to see?Directional selection is notoccurring. Instead, stabilizing selection is observed, where both very small and verylarge babies have higher mortality rates, favoring average birth weights. You wouldexpect to see a narrower distribution of birth weights centered around the average, asextreme weights are selected against.
Q5. Given this data what would you expect to see over time in beak lengthin these birds? What might the eventual result be?Overtime, the populationwill likely show an increase in the frequency of individuals with either verylong or very short beaks, while those with intermediate beak lengths willdecrease.Q6. Predict fitness for the phenotype of corolla, length for each scenario.How would the fitness differences you predicted impact ‘populationchange’? Assume a ‘normal distribution’ of phenotypes in a new population
of tobacco.The fitness differences predicted will determine how much variation ismaintained in the population and whether the population remains stable, shifts inparticular direction, or splits into multiple subgroups.Q7. Use a different color or line type to predict the distribution ofphenotypes after several generations of exposure to different pollinators.Q8. How can we explain this with evolution?Peepers who live in the north are better able to tolerate extreme cold than peepers inthe south.Consider the following when thinking about this:A. How did the ability to survive cold temperatures arise?Likely arose through naturalselection. In colder northern regions, peepers with genetic traits that helped themtolerate cold survived and reproduced more, passing those traits to future generations.B. Did it happen gradually in an individual?No, individuals didn’t evolve. The ability totolerate cold arose gradually over generations as individuals with cold-tolerant traitssurvived and passed them on.C. Did it happen gradually in a population?Yes, it happened gradually in the population.Over many generations, natural selection increased the frequency of cold-tolerant traitsin northern peepers.Q9. Natural selection in peepers acts on:A. Alleles in the frogs’ genomes that allow or don’t allow cold toleranceB. Individual frogs that may or may not have the cold tolerance alleleC. Populations of frogs in the north and southNatural selection acts on individuals with specific traits, such as cold tolerance. Theseindividuals either survive and reproduce, passing on their alleles, or they don't. Overtime, this process affects the population as a whole.Q10. Evolution in peepers occurs at the level of:
A. Alleles in the peepers’ genomeB. Individual peepersC. Populations of peepersWhile changes in allele frequencies are essential for evolution, the evolutionary processis reflected in the changes that occur within populations over time, rather than inindividual organisms.