BIOE140 Quiz 17-Oct-2008                                  Name:______________________

(Please write legibly)                                                                  Section:  Monday  or  Wednesday

 

 

1.    a. Describe 3 different currencies that might be optimized in animals.

       b. What are the advantages of group foraging?

       c. What are the costs of group foraging?

      

a.         Net energy – acquisition of resources

Time – optimal time spent at foraging patch (patch residence & optimal foraging)

Net energy supplied to progeny – fecundity

 

There is flexibility on this one. Another possible answer:

 

Net energy/time – individual

Net energy supplied to progeny (fitness)

Net energy supplied to colony.

 

      Another currency could be space – territory size.

 

b.        Advantages of group foraging: possibility of taking down a bigger prey, protection from predators (safety in numbers), information sharing, increasing inclusive fitness (kin selection), etc.

c.         Disadvantages: cheaters, easy to be detected by predators, when food is scarce it might not be enough for all members in the group, dominance, etc.

 

 

2.  In the runaway process of sexual selection, what trait is under selection in males and what trait is under selection in females?  Why is runaway sexual selection an example of maladaptive evolution?

 

Male trait under selection is a display trait.

Female trait under selection is female preferences.

In the process of runaway sexual selection a correlation between the traits can build and this could be counterproductive to Natural Selection because while it enhances reproduction success it can lower the overall fitness of the individual carrying the exaggerated display trait by lowering its survival (e.g higher predation risk).

 

3.  What is a greenbeard and what are the 3 defining characteristics?

 

  1. A signal:  genetically-based trait that has the potential to be detected by other members of the same species
  2. Recognition:  Individuals with the trait must be able to recognize the presence of the signal in other individuals
  3. Behavioral act:
    1. Allo- nasty to non-self-similar individuals
    2. Auto- nice to self-similar individuals

 

Other important points:

            This is a genetically-based phenomenon at work within a species (not between species)

            These behaviors benefit the gene, not necessarily the individual or species (i.e. the selfish gene)

            The Ògreen beardÓ is the name of this phenomenon and one potential trait.  There are many other examples of other traits that follow this same framework.