The History of Life on Earth

The figure shows one type of physical evidence that scientists use to understand Earth’s past. Imagine that you found this evidence on a mountaintop.

What could you conclude from your discovery?

• This organism is now extinct.

• This fossil is older than the mountaintop.

• The mountaintop is made of metamorphic rock.

• The rocks on this mountaintop were once at the bottom of an ocean.

Tags

NGSS.MS-ESS2-3

NGSS.MS-LS4-1

Many fossils are found only during certain periods in the geologic record. Scientists use these fossils to determine the relative ages of rock layers. The diagram shows relative ages of four fossils.

Which statement is true of a rock layer that contains Fossil F?

• It could also contain Fossil G.

• It was formed in Periods 1, 2, and 3.

• It is older than the rock layers that contain Fossil H.

• It is younger than the rock layers formed in Period 4.

Tags

NGSS.MS-ESS1-4

NGSS.MS-LS4-1

Which best describes a fossil that was discovered in rock at the base of a cliff?

• It is most likely an index fossil.

• It is likely younger than a fossil discovered halfway up the cliff.

• It is likely older than a fossil discovered in rock at the top of the cliff.

• It is likely younger than a fossil discovered in rock at the top of the cliff.

Tags

NGSS.MS-ESS1-4

Which is *not* an accurate statement about the fossil record?

• The fossil record represents less than one percent of all of the species that ever lived.

• Land organisms are more likely to fossilize than aquatic organisms.

• It is rare for the remains of a soft-bodied organism to become a fossil.

• Most fossils are found in sedimentary rock.

Tags

NGSS.MS-LS4-1

How does relative dating help determine the age of a fossil?

• It gives us the exact date an organism lived.

• It allows us to study the radioactive elements to determine the age.

• It determines whether a fossil formed before or after another fossil.

• It compares a fossil with its current living relatives and studies the differences.

The diagram shows a portion of the fossil record in sedimentary rock. Different rock layers and fossils are clearly visible.

Which statement is true of the fossils and rock layers shown in the diagram?

• Layer A contains the most recently formed fossils.

• Layer B contains the second-oldest fossils.

• The fossils in layer B are older than those in layer D.

• The fossils in layer D are the most recently formed.

Tags

NGSS.MS-ESS1-4

NGSS.MS-LS4-1

Juan is studying fossils. His teacher wrote the following statements on the board and asked the students to put them in the correct order to describe how fossils are formed.

1. Layers of sediment bury the entire skeleton.

2. Sediment builds up and turns to rock.

3. An organism dies, and its body begins to decompose.

4. Sediment begins to cover the organism’s skeleton.

Which is the correct order of events for fossil formation?

• 1, 3, 2, 4

• 2, 3, 4, 1

• 3, 2, 1, 4

• 3, 4, 1, 2

Which of these is not a significant discovery that Charles Walcott made in the Burgess Shale?

• well-preserved land organisms

• soft tissues of organisms preserved in great detail

• fossils over 500 million years old

• the remains of an ancient ocean

Scientists use evidence from their findings to support theories of life on earth. Which of these findings could not be used to provide supporting evidence that life on earth has changed over time?

• increasing complexity of fossils in younger rock layers

• increasing diversity of fossils in rock layers following an extinction

• transitional fossils

• rock layers with no fossils

Tags

NGSS.MS-LS4-1

At one time, several kinds of camels lived in Florida. The evidence comes from fossils found in Florida. Which object would be a fossil that shows that camels once lived in Florida?

• a sinkhole formed by a retreating glacier

• sedimentary rock that formed a long time ago

• a crystal formation suspended from the ceiling of a cave

• remains of an organism preserved by geologic processes

Tags

NGSS.MS-LS4-1