B2.8 Speciation/ Old and new species

Question 1

Where does evidence from early forms of life come from?

Answer 1

Fossils.

Question 2

Why are scientists not certain about how life began on Earth?

Answer 2

Because early forms of life did not leave much fossil evidence, they did not have bones and may have been disrupted by the Earth’s natural movements.

Question 3

What is a fossil?

Answer 3

The remains of organisms from many years ago foind in rocks.

Question 4

How are fossils formed?

Answer 4

1. from hard parts of animals that do not decay easily.
2. From parts of organisms that have not decayed because one or more of the conditions needed for decay are absent.
3. parts of the organisms are replaced by other materials as they decay.
4. As preserved traces of organisms.

Question 5

What can we learn from the fossil record?

Answer 5

How much or little organisms have changed as life developed on Earth.

Question 6

How might extinction be caused?

Answer 6

By changes to the environment, new predators, new disease , new and more successful competitors, a single catastrophic event.

Question 7

What is speciation?

Answer 7

When an isolated population becomes so different from the original population that a new species is produced.