24 - Evolution of Biodiversity

Question 1

What are methods we can use to study long term patterns of diversification?

Answer 1

Fossil data
- most biodiversity has gone extinct
- fossil record is incomplete

Molecular Phylogenetics
- calibrated with fossil data
- most mammilian families existed before the dinosaur extinction

Question 2

What is the equation to work out diversification rate per lineage?

Answer 2

D = S - E -> slope of the line

Question 3

What is S?

Answer 3

speciation rate

Question 4

What is E?

Answer 4

Extinction rate

Question 5

What do we expect if D > 0?

Answer 5

An exponential increase in the number of species

Question 6

What is the equation for the pull of the present?

Answer 6

= S / E

Question 7

Explain mammal species diversification

Answer 7

diversification rate differs a lot in mammalian clades

many clades show an initial bust and eventual slow down in diversification

Question 8

Give 3 reasons that a clade may differ in species richness?

Answer 8

• differences in carrying capacity
• differences in D
• differences in age

Question 9

How do you carry out sister clade comparisons?

Answer 9

• with a trait that has evolved repeatedly
• if you can identify sister clades with and without the trait
• compare number of species between the two clades

Question 10

What does it mean if there is a large pull of the present?

Answer 10

• there is a high extinction rate