5/13/24 - Lecture 23: Mutualism

Question 1

Intraspecific positive interactions

Answer 1

Individuals may benefit from higher densities of conspecifics due to increased probability of finding mates, reduced risk of predation, and cooperative foraging or breeding

Question 2

For positive density-dependent interactions, what do you replace r with?

Answer 2

Replace r with b(N-A)

Assume b > 0
A is the Allee threshold
When N is greater than A, the population increases
But when N is less than A, the population tends toward extinction

Question 3

Hyperbolic population growth

Answer 3

Population growth that is faster than exponential: dN/dt = bN^2

Question 4

Symbiosis

Answer 4

Close physical association. Can be beneficial or parasitic, and should not be confused with mutualism

Question 5

Obligate

Answer 5

At least one species could not grow and reproduce without the other

Question 6

Facultative

Answer 6

Both organisms may do better with their partner species, but can survive and reproduce without it