Module 8 Lesson 2 - 1

Get Focused

---

Cystic fibrosis (CF) is a disease in which the body produces abnormally thick and sticky mucus in the lungs and digestive system. Affected individuals have chronic difficulty breathing, respiratory infections, and poor weight gain. CF is an autosomal recessive condition that occurs in 1 in 2500 Caucasian births. Often in the past, people with cystic fibrosis did not live long enough to reproduce. With intensive therapy and medication, those with CF are now living long enough to have children and pass the CF allele to the next generation. Population geneticists are interested in what this means for the frequency of the CF allele in future populations.

In addition to identifying the conditions for Hardy-Weinberg equilibrium and the conditions for evolution, Wilhelm Hardy and Godfrey Weinberg have defined an equation that determines allele frequencies and genotype frequencies quite easily. Biologists can use this information to determine if populations are changing through adaptation eventually leading to evolution. If the population is evolving, such calculations will help determine what factors are causing the changes.

By the end of this lesson, you should be able to respond to these focusing questions:

• How can the Hardy-Weinberg formula, graphs, and data be used to study changes in populations over time?
  
• How do we analyze and interpret data to make predictions and decisions about population management?