1.

Natural selection is:

the idea that traits that help animals survive and reproduce become more frequent.

embryos sharing features in the late stages of development.

that all vertebrates have seven vertebrae in their necks.

the idea that traits that help animals survive and reproduce become more frequent.

2.

Name the structure that is unique to all vertebrates.

The backbone or spinal column is unique to all vertebrates.

3.

Humans, mice and giraffes share a common ancestor. What trait helps scientists understand that these organisms share a common ancestor?

They are all very different in size

They all have seven vertebrae in their necks

They once had wings

They are all bipedal

They all have seven vertebrae in their necks.

A _________ is a scientist who studies fossils.

A paleontologist is a scientist who studies fossils.

6.

Bipedal organisms walk on four feet.

True

False

False.

Bipedal organisms walk on two feet, not four.

7.

Fossils and genes are used to determine