Reference no: EM13340230

1. If most of the individuals in a population are doves and not many are hawks, how will the proportion of doves change over time?

a. Increase up to a point and then stop

b. Increase until almost everyone is a dove

c. Decrease up to a point and then stop

d. Decrease until almost nobody is a dove

e. No change.

2. Suppose 1% of the alleles at a chromosomal locus which affects social behavior are a version of a dominant gene that makes its holders altruistic in some way  (i.e. the gene confers altruism even if present only one of the an individudal’s chromosomes).   Then what percentage of the offspring of a random matings will carry the gene (approximately)?

a. 1%

b. 0.5%

c. 2%

d. 4%

I think you might find the remainder pretty tough; but they will be good for you!

3. Remember the Sgooks: Sgooks have litters of 8 offspring. Six of each litter normal get picked off by the single attack of a predator that waits until they are “just right” for eating.  However there is a new, rare gene (H) for Heroism.  If one of the offspring has a copy of H, it throws itself at the predator when it attacks and thereby saves the rest of the litter, though it, itself, gets eaten up.  We calculated that if 1% of the individuals in the population had H in one generation, then about 3% would have it in the next generation.  Thus the gene would increase in frequency over generations. Suppose that  litters were of size 4 and that the predator typically took 3 of the litter out. Would the proportion of H still increase over generations?

a. It would increase

b. It would decrease

c. It would hold constant.

4. The following applies to this and  the next question: Suppose that during fights over scarce resources large individual are just slightly more likely to win over smaller ones and that losers of encounters always get very, very seriously injured. Suppose moreover that there are two genetically determined personality types in the population: “Sensible” individuals who choose to fight with individuals smaller than themselves and run away from individuals larger than themselves, and “Paradoxical” individuals who choose to fight with individuals larger than themselves and run away from individuals smaller than themselves.

If most of the individuals in the population are paradoxical, how will the proportion of sensibles change over time?

a. Increase up to a point and then stop

b. Increase until almost everyone is a sensible

c. Decrease up to a point and then stop

d. Decrease until almost nobody is a sensible

e. No change.

5. If most of the individuals in the population are sensible, how will the proportion of sensibles change over time?

a. Increase up to a point and then stop

b. Increase until almost everyone is a sensible

c. Decrease up to a point and then stop

d. Decrease until almost nobody is a sensible

e. No change.

6. This is a VERY hard but rather interesting question.  I would definitely never ask anything this difficult on an exam.  In the evolution of Heros in the Skooks, we considered the case where the proportion of the H allele was initially quite low (0.5%); in that case we found that the Skook gene (i.e. allele) increases in frequency in the next generation.  However, an interesting question that a student raised is, this: "How common does the allele eventually become?"

a. It becomes very common (near 100%)

b. It increases a little for a few generations but eventually becomes almost entirely extinct

c. Somewhere in between (like maybe 40-80% but nothing like, say 99%)