BSC2010L Integrated Principles of Biology 1 Lab University of
Florida
Lab Manual
Evolution
Activity 1: Modeling Genetic Drift
In this activity, you will use beads in two different colors to model genetic drift of two alleles in a
population. Here we state red and blue, but you can use two other colors of beads, as long as they are
the same size. You can also use beans of different colors.
Overview: In part 1 of activity 1, you will first calculate the expected genetic frequencies for a
population at equilibrium. In part 2 of activity 1 you will then randomly sample individuals from the
model population and calculate observed genetic frequencies for 10 generations. You will compare the
expected values to the observed data. You are working with a diploid population, so each individual will
have two alleles for fur color.
Part 1: Preparing a Model Population
1. Select 50 red beads (B allele for red rabbit fur) and 50 blue beads (b allele for blue
rabbit fur).
2. Place the beads in a cup to model the gene pool of the population.
3. Mix the contents of the cup to randomly distribute the red and blue beads, set aside.
4. Record the number of alleles in each diploid organism of the population in Data Table 1.
5. Record the number of diploid individuals of the model population in Data Table 1.
6. Calculate the frequency of each allele in the model gene pool using the equation:
Individual allele number∈ population
Frequency= Total allele number ∈ population
7. Record the allelic frequency of allele B (p) in the model gene pool and the
allelic frequency of allele b (q) in the model gene pool in Data Table 1.
Data Table 1
Diploid allele number 100
Diploid individuals in population 50
Allelic frequency of p in the gene pool 0.5
Page 1 of 12
, Allelic frequency of q in the gene pool 0.5
Page 2 of 12
Florida
Lab Manual
Evolution
Activity 1: Modeling Genetic Drift
In this activity, you will use beads in two different colors to model genetic drift of two alleles in a
population. Here we state red and blue, but you can use two other colors of beads, as long as they are
the same size. You can also use beans of different colors.
Overview: In part 1 of activity 1, you will first calculate the expected genetic frequencies for a
population at equilibrium. In part 2 of activity 1 you will then randomly sample individuals from the
model population and calculate observed genetic frequencies for 10 generations. You will compare the
expected values to the observed data. You are working with a diploid population, so each individual will
have two alleles for fur color.
Part 1: Preparing a Model Population
1. Select 50 red beads (B allele for red rabbit fur) and 50 blue beads (b allele for blue
rabbit fur).
2. Place the beads in a cup to model the gene pool of the population.
3. Mix the contents of the cup to randomly distribute the red and blue beads, set aside.
4. Record the number of alleles in each diploid organism of the population in Data Table 1.
5. Record the number of diploid individuals of the model population in Data Table 1.
6. Calculate the frequency of each allele in the model gene pool using the equation:
Individual allele number∈ population
Frequency= Total allele number ∈ population
7. Record the allelic frequency of allele B (p) in the model gene pool and the
allelic frequency of allele b (q) in the model gene pool in Data Table 1.
Data Table 1
Diploid allele number 100
Diploid individuals in population 50
Allelic frequency of p in the gene pool 0.5
Page 1 of 12
, Allelic frequency of q in the gene pool 0.5
Page 2 of 12
