BSCI 360/708 Problem Set I Fall 2009
1. a) What is the degree of
relatedness between you and your grandfather? (1 pt.)
b) What is the
degree of relatedness between you and your mother's cousin? (1 pt.)
2. Explain the difference between broad
sense and narrow sense heritability. (1 pt.)
** NOTE: For the following questions, if selection
only operates on one
sex, you must
divide S by 2 to apply the breeder's equation.**
3. The heritability of maximum swimming speed in guppies is
0.8
and the population mean value is 1 m/sec.
What is the expected swimming speed of progeny from a pair of
guppies that can each swim 2 m/sec? (1 pt.)
4. In a study of the inheritance of song characteristics in Galapagos
finches
it was determined that the regression of the average maximum frequency
for
parents on the average maximum frequency of the offspring was 0.9 and
the
correlation among siblings which share the same mother and father was
0.3. Use
these statistics to estimate the heritability of maximum call frequency
for
each case and provide an explanation to account for any difference
between
them. (2 pts.)
5. The selection differential, S, on a trait in a natural
population is
measured by the covariance between lifetime reproductive success (LRS)
and that
trait. If the covariance between LRS and repertoire size in song
sparrows is 20,
the mean repertoire size among all males is 25, and the correlation
between a group of paternal half siblings is 0.2, what is the expected
mean repertoire size among
males in the next generation? (1 pt.)
6. Male red deer engage in roaring contests and the amount of
time a male
spends roaring is correlated to his mating success. The covariance
between the
number of offspring produced and the time spent roaring is 40. The
average time
spent roaring in the parental generation is 100 minutes.
If male offspring grow up and roar for
115 minutes, what must be the heritability for roaring? (1 pt.)
7. If the regression slope of copulation
duration for
average offspring on average parent ladybird beetles is 0.8 and the
average
parent has a mean copulation duration of 75 seconds, what is the
expected mean
of offspring when the copulation duration of their parents is 60
seconds? (1 pt.)
8. Two populations of spiders, A
and B, differ in their tendency to build
colonial webs, i.e. share common support threads. Population A builds
colonial
webs while population B builds individual orb webs. Individuals of both
sexes
from both species are brought into the lab and reciprocal hybrids are
produced.
All progeny from the cross A female x B male build colonial webs but
only
female progeny from the A male x B female cross build colonial webs.
Provide a
genetic explanation for this pattern of web building. (1 pt.)