In this activity, you will examine natural selection in a small population of wild rabbits. Evolution, on a genetic level, is a change in the frequency of alleles in a population over a period of time. Breeders of rabbits have long been familiar with a variety of genetic traits that affect the survivability of rabbits in the wild, as well as in breeding populations. One such trait is the trait of furless rabbits (naked bunnies). This trait was first discovered in England by W. E. Castle in 1933. The furless rabbit is rarely found in the wild because the cold English winters are a definite selective force against these rabbits who are not well adapted and therefore die before reproducing.
Note: In this lab, the dominant allele for normal fur is represented by F, and the recessive allele for no fur is expressed by f. Bunnies that inherit FF or Ff alleles have fur, while bunnies that inherit ff have no fur.
Problem: How does natural selection affect gene frequency over several generations?
Materials: 50 red beans, 50 white beans, one plastic cup ("mating cup"), three dishes labeled FF, Ff, and ff Procedure:
1. Fill in your hypothesis as to how natural selection affects gene frequency over several generations below:
*Clearly state your hypothesis (a tentative explanation or solution to the problem) ______________ ________________________________________________________________________________ ________________________________________________________________________________________________________________________________________________________________ *State what you would predict (if your hypothesis is true) about the frequency (number or amount) of F alleles and f alleles in the population of rabbits after ten generations, where ff bunnies are selected against (do not survive).
2. Working in groups of 2 students, get all needed materials. The red beans represent the allele for fur, and the white beans represent the allele for no fur. The plastic cup represents the English countryside, where the rabbits randomly mate. The dishes are labeled FF, Ff, and ff for the homozygous dominant, heterozygous, and homozygous recessive conditions.
3. Place the 50 red and 50 white beans (alleles) in the plastic cup and shake up (mate) the rabbits.
4. Without looking at the beans, select two at a time, and record the results on the data form next to "Generation 1." - For instance, if you draw one red and one white bean, place a mark in the chart under "Number of Ff individuals." Continue drawing pairs of beans and recording the results in your chart until all beans have been selected and sorted. Place the "rabbits" into the appropriate dish:...