BSCI 360/708 Problem Set I Fall 2008
1. The following phylogeny describes the evolutionary relationships, the wing colors and the habitats for seven hypothetical butterfly species which exhibit either cryptic or warning coloration. Assuming that wing color evolution occurred with the fewest possible changes, i.e. using parsimony, write the colors for each of the six ancestral species in the open boxes and indicate when an evolutionary change must have occurred by drawing a --- through the appropriate branch.
2. 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.
3. What is the degree of relatedness between you and your grandmother?
4. What is the degree of relatedness between you and your mother's niece?
5. Three inbred strains of whiptail lizard differ in their running speed. You can measure running speed among individuals in the parental generation as well as among individuals in the F1 and F2 generations. Which of these three groups would you choose to obtain an estimate of environmental variation?
6. 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.
** NOTE: For the following questions, if selection operates only on one sex, you must divide S by 2 to apply the breeder's equation.**
7. 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 20. The average time spent roaring in the parental generation is 100 minutes. If male offspring grow up and roar for 105 minutes, what must be the heritability for roaring?
8. 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 50 seconds?
9. 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 9, 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?
10. The heritability of maximum swimming speed in guppies is 0.7 and the population mean value is 2 m/sec.
What is the expected swimming speed of progeny from a pair of guppies that can each swim 3 m/sec?