1.  A population biologist made the following observations regarding two forms of the banded land snail, Cepaea nemoralis, inhabiting a field in the English countryside:
 

	Banded	Solid
Population Size	3,600	3,000
Survivorship to adulthood	12%	15%
Probability of mating	0.72	0.85
Avg. Fecundity (eggs/mated adult)	500	300

What are the relative fitnesses of the two forms?
 

2.  The relative fitness of black squirrels in the Black Forest is 1.0, while for grey squirrels it is 0.80 and for white squirrels it is 0.10.   If the current frequencies of the incompletely dominant black gene and white gene are p_B = 0.60 and q_W = 0.40, respectively, predict p_B next generation.
 

3.  A geneticist founded a population of Drosophila with flies from three pure cultures.  Included were 40 wild-type flies, 20 sepia-eyed flies (an autosomal recessive) and 15 flies with wrinkled wings (an autosomal dominant, unlinked to sepia).  After several generations, the fly population appeared to be in Hardy-Weinberg equilibrium.  What are the expected frequency of sepia flies (regardless of wing type)?  Of flies with completely wild-type features?
 

4.  The geneticist then decided to start a new culture with a large sample of adults from this population, raising the temperature in the incubator from 20°C to 25°C.  Although larvae are unaffected, temperatures this warm are fatal to adult sepia flies.  What will be the frequency of the sepia gene among the first generation of larvae developing at 25°C?
 

5.  In conditions as warm as 25°C, Drosophila medium tends to become so sticky that wrinkled-wing flies often become entrapped.  If wrinkled flies are 40% more likely to die than flies with normal wings, what will be the frequency of the wrinkled gene after one generation?   What will be the frequency of wrinkled flies in two generations?
 

6. In an industrialized region, the fitness of Biston betularia moths is 1.0 for the dark form (DD and Dd) and 0.47 for the light form (dd).  Calculate delta-p for the following situations:

a) p_D = 0.10, q_d = 0.90
b) p_D = 0.40, q_d = 0.60
c) p_D = 0.90, q_d = 0.10
 

7. In a region where industrial pollution has been under control for a number of years, the fitness of Biston betularia moths is 0.47 for the dark form and 1.0 for the light form.  Calculate delta-p for the same three situations shown in question #2 above.
 
 
 

ANSWERS:

1) W_banded = 1.0, W_solid = 0.89
2) 0.726
3) 0.071, 0.594
4) 0.211
5) 0.14, 0.179
6) (a) 0.075,   (b) 0.09,   (c)  0.0048
7) (a) -0.048,     (b) -0.12     (c) -0.010