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1

How many mass extinctions have there been so far?

5

2

What are the main contributors to a decrease in biodiversity?
Give a percentage if possible

Exploitation and habitat degradation (68.4%)
Climate change and invasive species come second

3

What makes a species more at threat from extinction?

(3 points)

Small populations/small geographical range

Species tied to a habitat favoured by humans

Those higher in the food chain

4

Who pointed out that there were discontinuities in the fossil records?

Mary Anning (early 1800s)

5

Who found that whole clusters of taxa disappeared at the same time in the fossil record?

A French palaeontologist called Cuvier (1825)

6

What famous scientist didn’t believe there had been mass extinctions?

Darwin

7

What are the five mass extinctions?

1. Late Ordovician
2. Late Devonian
3. Late Permian
4. Late Triassic
5. End-Cretaceous

8

What is the Cretaceous-Paleogene extinction also known as and when was it?

K/T boundary
65 million years ago

9

What happened after the K/T boundary?

75% species extinct
Mammals replaced dinosaurs
Flowering plants diversified
Insects co-evolved with plants

10

What is believed to of caused the mass extinction at the K/T boundary?

Large asteroid impact approx. 1000x greater than Krakatoa eruption

11

What are the two hypotheses for the Pleistocene mammal extinctions?

1. Environmental deterioration: retreat of glaciers, corridors lost

2. Human overkill: beringia appeared allowing spread of H.sapiens into North America

12

Give an example of competitive co-evolution:

The predatory mite, which ate prey to extinction then also became extinct

13

What was it called when all the continents were joined, and when was it?

Pangea
220 million years ago

14

Why did land vertebrates in Euramerica have a slow migration in the Late Permian period?

Hindered by mountains and southern deserts