Lecture 28

Question 1

What is a population in ecology?

Answer 1

A group of the same species living in the same area, interacting and breeding.

Question 2

How is population size estimated?

Answer 2

Using extrapolation or the mark-recapture method.

Question 3

What is the formula for population change?

Answer 3

A: ΔN/Δt = B - D
(B = births, D = deaths)

Question 4

What is the exponential growth model?

Answer 4

Growth in an ideal, unlimited environment.
Formula: dN/dt = rN

Question 5

What is carrying capacity (K)?

Answer 5

The max population an environment can support.

Question 6

What is the logistic growth model?

Answer 6

Growth slows as population nears K.
Formula: dN/dt = rmaxN × (K - N)/K

Question 7

What is the Allee effect?

Answer 7

Difficulty surviving/reproducing when population is too small.

Question 8

What is r-selection vs K-selection?

Answer 8

r-selection: Maximize reproduction (low density)
K-selection: Traits sensitive to density (near K)

Question 9

What causes snowshoe hare population cycles?

Answer 9

Predation (not food shortage) is the main driver.

Question 10

Is human population growth still exponential?

Answer 10

A: No, it’s slowing but still increasing (~8 billion now).

Question 11

What is an ecological footprint?

Answer 11

The land/water needed to sustain a person’s lifestyle (avg. 1.7 gha/person).