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?