Macroevolution 2

Question 1

What is species persistence?

Answer 1

A species ability to survive and maintain a stable population over time

Question 2

What is an example of species persistence ?

Answer 2

Coelacanth, a carnivorous fish
It was thought to be extinct 66 million years ago, until a living one was found in 1938
It is called the living fossil

Question 3

What are examples of extinct animals ?

Answer 3

1. Sabre toothed cat
2. Giant ground sloth
3. Woolly mammoth

Question 4

How old is earth ? How long has there been life ?

Answer 4

4.55 billion years old
There has been life for the last 3.8 billion years
Bacteria dominated for the first 3.1 billion years

Question 5

What is the atmospheric revolution ?

Answer 5

The period when photosynthetic microorganisms (mainly Cyanobacteria) began producing oxygen via photosynthesis, leading to an increase in atmospheric oxygen.
It marks the arrival of mass extinction.
Also called the great oxygenation event (GOE).

Question 6

What is the K-T event ?

Answer 6

The Cretaceous-Tertiary event
A mass extinction event that marks the end of the dinosaurs 65 MYA
Likely due to impacts of giant meteorites in Mexico and volcanic eruption in India

Question 7

What are mass extinctions characterised as ?

Answer 7

Times when the earth looses more than three-quarters of its species in a short interval

Question 8

What is the sixth mass extinction event ?

Answer 8

The ongoing human-driven extinction crisis.
It’s called sixth because it is comparable in scale and speed to the five previous mass extinctions.
Also called the Holocene extinction.

Question 9

What are reasons for species extinctions ?

Answer 9

1. Climate change
2. Global movement of animals and plants- invasive species
3. Habitat loss
4. Pollution

Question 10

What is continental drift?

Answer 10

The theory that the Earths continents have moved over geological time and continue to move today
Proposed by Alfred Wegner
There is fossil evidence

Question 11

What is Wallaces line ?

Answer 11

An imaginary geographical boundary that separates the fauna of Asia from that of New Zealand and New Guinea
West of the line: animal species are similar to those in Asia
East of the line: similar to Australia

Question 12

What were the genetic consequences of the Pleistocene ice age ?

Answer 12

1. Population bottlenecks
2. Genetic drift
3. Speciation

Question 13

What are the effects of ice ages on fauna ?

Answer 13

1. Extinction of species
2. Formation of barriers to movement
3. Splitting of populations and subsequent speciation