Lecture 17: Coevolution and Cooperation (Exam 3)

Question 1

why cooperation appears problematic from a theoretical standpoint

Answer 1

• natural selection favors traits that confer the greatest reproductive success, but cooperation doesn’t always lead to increased reproduction
• ex: warning calls increase the chances of one organism being eaten but protect other organisms in the population

Question 2

Three hypotheses that help explain the persistence of cooperation

Answer 2

1. kin selection: increase fitness of relatives
2. direct fitness benefits: cooperating increases survival rates
3. indirect fitness benefits: can occur in populations with high relatedness

Question 3

what is coevolution

Answer 3

• participating increases survival and reproduction
• relationship strengthens over time
• ex: only one species of orchids can be pollinated by one species of moths (long tongues, long nectar tubes)

Question 4

definition of evolutionary arms race

Answer 4

1. predators hunt prey
   - produces selection pressure for traits that increase prey ability to evade predators
2. over generations, prey become better at evading capture
   - produces selection pressure on predators for traits that increase ability to capture prey

Question 5

What the terms mean in the competition equation

Answer 5

equation: dN1/dt = 1 - (N1+ aN2) / K1
aN2 = per capita competitve effects of species 2

Question 6

what effects you could observe by changing different parameters

Answer 6

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