In this second case you will modify the simulation to make itmore realistic. In the natural environment, not all genotypes havethe same rate of survival; that is, the environment might favorsome genotypes while selecting against others. An example is thehuman condition sickle-cell anemia. It is a condition caused by amutation on one allele, in which a homozygous recessive does notsurvive to reproduce. For this simulation you will assume that thehomozygous recessive (ff) individuals never survive whileheterozygous (Ff) and homozygous dominant (FF) individuals alwayssurvive.
Create a second data chart similar to Chart 2. Start again withyour initial genotype and produce your \"offspring\" as in Case 1.This time, however, there is one important difference. Every timeyour offspring is ff it does not reproduce. Because we want tomaintain a constant population size, the same two parents must tryagain until they produce two surviving offspring. Repeat theprocedure 49 more times. In other words, every time you pull an ffcombination, do not record it. Put it back and pull again.
Before you begin, make a prediction about what you expect toobserve regarding this population's allele frequency over severalgenerations. Record your hypothesis in your lab report.
Record your results as you did in Case Study 1. Replenish yourbag according to the previous draw for the remainder of the fourdraws.
Now that you have collected data on your own, be sure to sharewith your partner(s) to compile within the lab report.
Chart 2 (example data chart)
Allele Frequencies |
| Allele F | Allele f |
Generation | Number | Percentage | Frequency | Number | Percentage | Frequency |
Start | 75 | 75 | 0.75 | 25 | 25 | 0.25 |
1 | | | | | | |
2 | | | | | | |
3 | | | | | | |
4 | | | | | | |
5 | | | | | | |
6 (if needed) | | | | | |
