Modeling the Geological Time Scale HASPI MS Medical Earth Science Lab 02b Scenario

The geological time scale marks major events that have happened throughout the history of the Earth. The Earth has changed significantly throughout time and it is estimated that 99.9% of all organisms that have one time lived on Earth are now extinct. By examining the fossil record scientists can develop a range of time when a species, or group of species, lived and became extinct. In this activity you will create a model of the geological time scale to get a better idea of when major events have occurred during Earth’s history.

Materials

Paper strip Scissors Ruler Geological Event cards Tape Pen/pencil

Directions

Task Response

1 Cut and tape together 5 meters of paper strip. You will need 3 sheets of the “Time Scale” sheets to make 5 meters.

2 Cut out the “Geological Event Cards.”

3

Lay out the 5-meter paper strip on the floor or in an open space. Using a ruler, you will be marking out and taping the geological event cards on the paper strip to create a model of the geological time scale. For this activity:

1 mm = 1 million years 1 cm = 10 million years

10 cm = 100 million years 1 meter = 1 billion years

4

Each of the geological event cards has a description and a date. Starting with the card with the most recent date titled “Present.” Tape the “Present” card at the very beginning of the paper strip.

5

Find the next most recent geological event card. For example, it should be the “Cenozoic Era Start” at 65 million years. Using the ruler, measure 6.5 cm from the first card. Make a mark on the paper strip and tape the “Cenozoic Era Start” card in place at the mark.

6

Continue finding the next most recent geological event card and continue measuring and taping the cards in place. Remember that every date and measurement should start from the BEGINNING of the paper strip.

57 Geological Time, the Fossil Record, & Health; HASPI MS Medical Earth Science Lab 02

   

7 Once complete, answer the following questions based on your geological time scale model. 8

When did the Earth begin?

9

When did life first appear on Earth?

10

When have most of the major events on Earth occur?

11

What era are we currently in?

12

In what era did dinosaurs and mammals appear?

13

In what era did insects and reptiles appear?

14

Why do you think the appearance of oxygen in the atmosphere was important?

15

Notice that the dinosaur extinction led to an increase in mammals. How do you think this has shaped the organisms currently living on Earth?

16

In what habitat did most life exist during the Paleozoic era? Explain your answer.

17

The first humans appeared approximately 200,000 years ago. If the Earth is 4.6 billion years old, what percentage of time have humans been on the Earth?

58 Geological Time, the Fossil Record, & Health; HASPI MS Medical Earth Science Lab 02

18

Why is it important to study the history of the Earth?

Geological Event Cards Modeling the Geological Time Scale

HASPI Medical Earth Science Lab 02b

Cut out each of the following cards on the dotted line

Present

Current Date

Beginning of Earth

4.6 billion years

Mesozoic Era Start

245 million years

Dinosaur Extinction

66 million years

Cambrian Explosion

542 million years

Earliest Life

3.8 billion years

First Mammals

200 million years

First Land Animals

430 million years

First Insects

400 million years

First Primates

85 million years

First Reptiles

300 million years

First Land Plants

450 million years

Oceans/Continents Form

Oxygen in Atmosphere

2.4 billion years

Eukaryotes Evolve

1.8 billion years

First Fish

500 million years

59 Geological Time, the Fossil Record, & Health; HASPI MS Medical Earth Science Lab 02

4.4 billion years Paleozoic Era Start

540 million years

First Amphibians

360 million years

Cenozoic Era Start

65 million years

First Birds

150 million years

60 Geological Time, the Fossil Record, & Health; HASPI MS Medical Earth Science Lab 02