Scenario #3
In the year 2850, humans successfully colonized Mars. The Martian modules that were constructed could hold only a small population of people. It is now a century later, and the population on Mars has grown to 600 people. Of the current Mars population, 45 people express the recessive phenotype for phenylketon- uria (PKU) syndrome (pp genotype).

q2 –

q –

p –

p2 –

2pq –

Conclusion Questions
Use this information to help you answer the following questions:
The original population’s actual genotype frequencies were: PP – 0.53, Pp – 0.25, pp – 0.22.

1. Is the current population in Hardy-Weinberg equilibrium? Yes or No

2. Is the current population evolving? Yes or No

3. If the current population is evolving, what type of effect is responsible for genetic drift?

Final Conclusion Question
Describe the difference between a population evolving and being in Hardy-Weinberg equilibrium, giving your explanation in terms of allele frequencies. Can a population be evolving and also be in
Hardy-Weinberg equilibrium? Explain why or why not.