Biol. 317 - Lecture notes – Chapter 15 Stability and Change


Review Questions/Lecture Outline

What are ammonites? When did they go extinct? What is one mentioned hypothesis that might explain why their cephalopod relatives, the chambered nautilus (not to mention squids, etc.) survived this extinction event and ammonites did not?

What is succession? Contrast pioneer and climax species.

Dr. Wayne Sousa studied succession patterns in a rocky intertidal boulder field environment. Explain the pattern of succession and his main conclusions. What is the 'take-home' story?

Review the previously-covered concept of r- vs. K-selected species.

Review the previously-covered concept of different classes of symbiosis.

Why do parasites and pathogens tend to become less virulent over time?

How can territoriality influence competition for resources?

Review the previously-covered concept of density-dependent vs. density-independent mortality factors.

Why does it matter whether a species commercially harvested by humans experiences density-dependent or density-independent mortality factors?

Contrast the earliest and later hypotheses that sought to explain outbreaks in the crown-of-thorns sea star. What do the more recent views suggest about how populations of organisms might be limited?

Why is there little consistent pattern of success in herring and haddock stocks? What are the important stages in their life?

Describe the conditions that lead to an El Nio event, such as the 1982-1983 or 1997-1998 events.

Why are organisms at higher trophic levels often especially vulnerable to El Nio effects?