# Lab 3: Hardy-Weinberg Equilibrium

Name: ______________________________

Section: _____________________________

Student ID#:__________________________

Please read the section of your assigned textbook that covers Hardy-Weinberg Principle of Equilibrium. It will explain how this equation is used to determine the percent of a population that carries heterozygous traits, and how these unexpressed traits can appear in future generations.

• $$q$$= Dominant Trait
• $$r$$=Recessive Trait
• $$q$$=Subordinate Dominant Trait

These formulae assume stability in population:

$$(q+r)^{2} \qquad=\quad q^{2}+2 q r+r^{2}$$ $$\begin{array}{l}{\text { if } q=.5 \& r=.5, \text { then } q^{2}=25, r^{2}=.25 \& 2 q r=.50} \\ {\text { If } q=.4 \& r=6, \text { then } q^{2}=16, r^{2}=.36 \& 2 q r=48}\end{array}$$

$$(q+p+r)^{2}=q^{2}+p^{2}+r^{2}+2 p q+2 p r+2 q r$$$$\begin{array}{l}{\text { If } q=3, p=3, \& r=4 \text { then next generation will show }} \\ {q^{2}=.09, p^{2}=.09, r^{2}=.16,2 p q=.18,2 p r=.24, \& 2 q r=.24} \\ {\text { or } q=.51, p=.33, \& r=16}\end{array}$$

1) What will your distributions be in the second generation if $$q=.69 \ \& \ r=.31$$:

2) What will your distributions be in the second generation if $$q=.31 \ \& \ r=.69$$:

3) What if $$q=.33, \ p=.34, \ \& \ r=.33$$, what will be your populations and their expression in the next generation?

4) What if $$\mathrm{q}=.9 \ \mathrm{p}=.05, \ \& \ \mathrm{r}=.05$$, what will be your populations and their expression in the next generation?

5)a) In the current generation, $$q=.9 \ \& \ r=.1$$. If q is completely selected against, what will the distributions be in the next generation? (equation)

b) What will these distributions be if r is completely selected against? (essay)

6) What is the relationship between the dominance of a trait, and its rate of survival if it is selected against by either natural or artificial selection? (essay)

7) In the current generation the distribution of traits is $$q=.4, \ p=.4, \ \& \ r=.2$$. What will the distributions be in the next generation? (equation)

b) Given your answer to 7, what would you expect if during the second generation q is completely selected against, what will the third generation‟s distribution look like? (essay)

c) Given your answer to 7, what would you expect if during the second generation p is completely selected against, what will the third generation‟s distribution look like? (essay)

d) Given your answer to 7, what would you expect if during the second generation r is completely selected against, what will the third generation‟s distribution look like? (essay)