Exam 3 Study Questions
are studying a small rodent in a field system. You notice that the rodent makes a similar type of call each
day at the same time. You are
interested in knowing if this rodent is communicating or simply making a
random noise. What should you look
for when the rodent makes this noise?
most cases of animal communication, the communication is not intentional
(the animals do not think about the call) and the call does not convey any
information about the external environment. Describe two exceptions to this general rule in primates.
requires a signaler and a receiver, two individuals probably with
different interests and needs.
What must be true of this interaction for communication to
occur? (Hint: 2 criteria must be
were long confused about how dominant Saddle-Backed tamarin females
communicated with subordinate females so that the subordinates did not
breed in this cooperative system.
What is the mechanism for communication in this system?
general, young birds do not over-exaggerate their food-begging calls
although it seems as if natural selection should favor them doing so. Why not?
- Why do
we question the evolution of sexual reproduction. Clearly explain the cost of sex.
the cost of sex is so great, why do most organisms do it? Explain in lay terms the theories of
Mueller’s ratchet and Environmental Unpredictability and how they might
explain the evolution of sexual reproduction.
is ISOGAMY and ANSIOGAMY? Give an
example of an organism that is Isogamous and one that is Ansiogamous.
gametes are much less costly to produce than large gametes. Given this information, why are many
organisms ansiogamous? Why don’t
we all produce small gametes?
sex that gives the majority of parental care to offspring generally
becomes a limiting resource for the other sex. Why? After
explaining that first statement, give an example of an organism that
exhibits sex role reversal and explain why the roles are reversed in that
is the difference between Intrasexual and Intersexual Selection? Why is Intrasexual selection so
again, we have discussed the topic of alternative mating tactics—you
should be experts on this by now.
Think of the examples of jacks and parrs, streakers and large male
fish. What is necessary for the
maintenance of alternative mating tactics? Be able to explain the details of one alternative mating
competition can be a tactic used in both Intrasexual and Intersexual
selection. Describe sperm
competition in the two types of selection systems—How do males engage in
sperm competition and how do females?
When do you predict sperm competition to evolve?
should a male guard his mate?
when males are fighting it out for access to females, the females may have
the last say in the matings and in the success of offspring. Describe two ways that female engage in
Inter-sexual selection and choose the best mates for the production of the
was the documentation of widespread extra-pair copulations (EPC) in
animals, especially birds, such a shocking discovery? What does the frequent occurrence of
EPC’s suggest about monogamous mating systems in general?
the four hypotheses for why females might engage in EPC’s? Why is it difficult to distinguish
which might be the primary force driving EPC’s.
is the difference between social and genetic monogamy. What patterns of parental care may you
expect to see in social versus genetic monogamy?
- Why is
polyandry more common in birds than mammals?
is defined as a mating system where a male mates with more than one female
but a female mates with only one male. Four different types of polygyny
have been defined according to the distribution of females and other
resources (food, territory). What
are the four types of polygyny and how do they differ in relation to the
distribution of females and resources?
are a scientist studying a lekking species of bats in the tropics. You are very interested in
understanding whether this system is best described by the Hot-SPOT model
or the Hot-SHOT model. Design an
experiment to test which model the bat lek fits best.
where several males form mating bonds with several females, is fairly
common in the large, flightless birds such as South American Rheas. What is driving this mating system?
1. You are a scientist studying two previously
un-described bird species in Amazonia.
One species appears to be a type of warbler (a small insectivore) while
the other species is a type of sandpiper (a medium sized shorebird). From your observations during the first
nesting season, it appears that both warbler parents participate in the care of
the young but only the male raises the sandpiper chicks. What types of data would you seek to collect
next season to determine the causes for the different parental care strategies?
hypothesis states that parents should lay just enough eggs to maximize the
total number of surviving offspring.
Interestingly, most birds lay approximately one fewer egg per
clutch than Lack’s hypothesis would predict. How can you explain the difference between observed and
actual clutch size?
is the Concorde Fallacy and how would you relate it to how males and
females should make decisions on parental care investment?
what criteria would you predict a male animal should provide parental
a scenario in which both parents might desert their offspring?
of parents do not always equal the interests of the offspring, and vice
versa. Why is there a conflict
between parents and offspring?
inevitable conflict between parents and offspring often results in
offspring competing for resources.
In extreme cases of competition, sibilicide can result. Describe and offer and example for the
differences between “obligate” and “facultative” siblicide.
is kin selection? How does
Hamilton’s rule describe the occurrence of kin selection?
first glance, the occurrence of brood parasitism seems a complete
mystery. With an educated eye, how
would you explain why host parents don’t always throw out the eggs or
young of the parasites.
(Hint: I can think of at
least 3 reasons).