Exam #3 - Evolutionary Events Vocab

Question 1

Most Compelling Evolutionary Events

Answer 1

1. Periods when species originate and diversify rapidly
2. Periods when specie go extinct rapidly

Question 2

Adaptive Radiation

Answer 2

When a single lineage rapidly produces many descendant species with a wide range of adaptive forms

Question 3

What Triggers Adaptive Radiation?

Answer 3

1. Extrinsic factor, i.e. favorable new conditions in environment
2. Intrinsic factor, i.e. evolution of key morphological, psychological, or behavioral traits

Question 4

Fauna

Answer 4

A collection of animal species
- Microfossils
- First microscopic fossils
- Cambrian macroscopic fossils

Question 5

What Triggered the Cambrian Explosion?

Answer 5

1. Higher oxygen levels: makes aerobic respiration more efficient
2. Rise of algae: produced more oxygen & higher quality food
3. Evolution of predation
4. New niches beget more new niches
5. New genes, new bodies

Question 6

Mass Extinction

Answer 6

The rapid extinction of a large number of diverse species around the world; when at least 0% of the species present are wiped out within 1 million years

Question 7

Background Extinction

Answer 7

The lower, average rate of extinction observed when a mass extinction is not occuring