Lecture 8 Predation, Parasitism and Disease

Question 1

what is the relationship between predator and prey population like?

Answer 1

1.occurs in cycles based on the feeding relationship between the two species

2.when population of prey is high, predator population is also high, come in a drive the population down

3. predators eat so many the population is low again and predator numbers decrease due to starvation
4. lack of predators leads to a rapid increase in. prey population

Question 2

what is antagonistic co-evolution?

Answer 2

prey adaptations to predator, predator adaptations to prey

Question 3

what is the red queen hypothesis?

Answer 3

predators constantly evolves to eat prey, prey is constantly evolving to not get caught by predator

Question 4

what is the life dinner principle?

Answer 4

prey species experiences stronger selection than their predators so that it can escape

eg a rabbit runs faster then a fox because a rabbit is runnings for its life whereas a fox is running for its dinner

Question 5

what are inducible defences?

Answer 5

defences induced when there is a threat or attack

Question 6

what was Robert pains experiment?

Answer 6

He removed ochre starfish (Pisaster ochraceus) from a seashore in Washington state, revealing that a single predator could control the abundance, diversity and distribution of other organisms sharing its ecosystem

• (starfish) remaining in its ecosystem prevents mussels from competitively excluding other species on rocky intertidal communities, maintaining biodiversity

Question 7

what is the enemy release hypothesis?

Answer 7

the idea that invasive species are less impacted by enemies (e.g., herbivores) than native species, because in the new geographical location, the invasive species are not inhibited by parasites that stunted the growth of their population in their native environment.

Question 8

what is the application effect in terms of diseases?

Answer 8

more host or vector species can support larger populations or disease causing organism, increasing risk to humans and animals

Question 9

what is the dillution effect?

Answer 9

for disease than affect many hosts, host diversity can dilute or decrease disease risk to humans or animals

Question 10

what are latitude ranges in species richness?

Answer 10

there are far more species near the tropics or lower latitudes

warm and wet weather aids in primary productivity