6/3/24 - Lecture 32: Extinction and the Anthropocene

Question 1

Effect of population size on extinction risk

Answer 1

Small population sizes increase extinction risk because they are more vulnerable to ecological factors and due to Allee effects (more difficult finding mates)

There also may be genetic drift, which makes it more likely that deleterious alleles will be fixed. Or inbreeding depression.

Question 2

Which are more likely to go extinct: big or small species? Why?

Answer 2

Big species are much more likely to go extinct. Humans hunt them and they need more food and thus more habitat. This makes them more vulnerable to habitat loss.

Question 3

Species at risk

Answer 3

Large animals, K-selected species, endemic & narrow geographical range species, resource specialists/specialized niches, and those vulnerable to predation/hunting

Question 4

What happens when habitat sizes are reduced?

Answer 4

Edge effects are exacerbated

Question 5

What is the problem with edges in a habitat?

Answer 5

Edges are poor habitat

Question 6

How can we design better-protected conservation areas?

Answer 6

Large core areas rather than many small areas
Buffer zones (limit edge effects)
Increase connectivity