Asynch Lecture: Conservation and Diversity

Question 1

When earth formed on a geologic timescale, how long did prokaryotes form after the earth formed?

Answer 1

one billion years apart ; prok. formed several billion years ago

Question 2

When earth formed on a geologic timescale, how long did Homo Species form after the earth formed?

Answer 2

2 million years ago

Question 3

When earth formed on a geologic timescale, how long did Homo sapiens form after the earth formed?

Answer 3

hundreds of thousands of years

Question 4

What is background extinction rate?

Answer 4

low level, steady, constant rate of species loss

Question 5

What is mass extinction rate?

Answer 5

a rapid decline in a large number of species, much higher than background extinction rate

Question 6

What are adaptive radiations?

Answer 6

periods of evolutionary change in which organisms form many new species with adaptations specialized to different niches

Question 7

What are 2 estimates for modern extinction rates?

Answer 7

1. Highly conservative estimate
2. Conservative estimate

Question 8

What is the Highly conservative estimate extinction estimate?

Answer 8

includes only species classified as extinct

Question 9

What is the Conservative estimate extinction estimate?

Answer 9

includes only species classified as extinct, extinct in the wild, and presumed extinct