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Earth History Name 1000 millimeters of time Date Hour

Do you have any idea how old the earth is? The evidence indicates it is almost 5 billion years old. (4.6 billion years to be more precise). Sometime during that 5 billion years, a very important thing happened: life began! It is not certain exactly when this event took place, but the remains (fossils) of ancient plants and animals give us some idea of when the most primitive living organisms appeared.

Fossils of these primitive organisms, the bacteria and blue green algae, have been found in rocks about 3.3 billion years old. Evidence indicates that these were the only forms of life that existed until about 600 million years ago. Since that time a tremendous variety of organisms have inhabited the earth, many of which are now extinct.

In this investigation you will be able to see when important events in the history of the earth took place. To see these events, you will use a meter as the measure of the age of the earth. The divisions of the meter stick will represent units of time. Your problem is to determine when on the meter stick time scale these important events took place.

Part A

Problem: What units of time do the units on the meter stick represent?

Directions:

1. The smallest units on a meter stick are millimeters. There are 10 millimeters in each centimeter and 100 centimeters in a meter. Therefore, there are 1000 millimeters in 1 meter. Use the centimeter and the millimeter to represent units of time in the age of the earth.

2. Obtain a piece of paper over a meter in length. Measure with a smaller ruler 30 cm from the edge of the right side of the paper and 20 cm from the bottom of the paper. Draw a line straight down from this point. Mark this line 0 (present time).

3. Place the meter stick on the paper, with the lowest numbers (beginning with 1) at the right of the paper where your line is. You will have to place the meter stick upside down to do this.

4. Draw a line 1 meter in length from the line you constructed in #2. This line will represent the age of the earth or 5 billion years. Do not remove your meter stick.

5. With the meter stick still in its place, make a mark on the paper at each of the following centimeter divisions of the meter stick:

o a mark at each of the first 12 centimeters (a mark at 1 cm, 2 cm, 3 cm, etc. up to 12 cm.) a mark at 40 cm a mark at 60 cm a mark at 80 cm a mark at 100 cm (left end)

6. Using the smaller ruler, extend these marks to the bottom of the paper.

Earth Hist 1000 milli-MD.docx 03/18113

7. Now, what units in time do these marks represent? Let 1 centimeter = 50 million years! Therefore, the time represented from the right-hand side of the meter stick (0), to the mark you made at 1 centimeter is 50 million years. Write the word present on the 0 line that extends to the bottom of the paper. Write the words 50 million on the line you drew down from the mark at 1 centimeter.

8. Indicate the amount of time represented by each line: 1 cm = 50 million (you should have already done this), 2 cm = 100 million, 3 cm = 150 million and so on up to 12 centimeters.

9. Indicate the amount of time represented by the remaining lines i.e. 20 cm = 1,000 million years or 1 billion years, 40 cm = 2 billion and so on.

10. Using your smaller ruler make a mark at each of the first 10 millimeters on the line starting from the right. Therefore, only the first centimeter will be divided this way.

PartB

When did some of the important events in the history of the earth take place?

Directions:

1. The chart on the next page lists some of the important events in earth history and the number of years ago that they are believed to have occurred. Study the chart. If you do not know the meaning of a particular word, use your textbook as a resource to find the meaning.

2. Using your time scale, draw a line with your ruler and point to the part of the time line when the event took place. Write the name of the event on this line.

3. At the end of the line created from #2, draw a picture to represent the event. Make your picture large and colorful. Use creativity to represent the event!!

4. When completed, answer the questions provided.

Earth Hist 1000 milli-MD.docx 03/18/13 2

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Event in Earth History

1. First flowering plants

2. Appearance of insects

3. Appalachian mountains fomled (folded)

4. End oflast ice age

5. Columbus discovered America

6. First dinosaurs appeared

7. First seed plants appeared

8. Earliest fossils - bacteria and blue green algae

9. Rocky mountains formed (folded)

10. Early humans

11. Dinosaurs become extinct

12. Reptiles appear

13. Swamps begin to form earth's coal

14. First moon walk

15. First amphibians

16. First primates

17. Grand Canyon cut by Colorado river

18. Abundant invertebrates m the seas (trilobites, sponges, etc.)

19. First birds

20. First mammals

21. First evidence ofland plants

22. First sharks

23. Discovery ofthe structure of DNA

24. Sea invades Atlantic and Gulf coastal plains

25. First fish

Number of Years Ago

150 million

480 million

230 million

12 thousand

503 years

225 million

300 million

3.3 billion

65 million

3.5 million

65 million

290 million

280 million

26 years

400 million

60 million

10 million

530 million

170 million

168 million

500 million

400 million

42 years

100 million

560 million

Earth Hist 1000 milli-MD.docx 03118/13 3

< Challenge Biology Name ____________________________ Earth History Date _____________ Hour ______ Time line questions

1. When did the first organisms appear and what were they?

2. What do the following units of measurement equal in time?

a. 1 cm=

b. lrhm=

c. 12cm=

d. 10 mhl=

e. 20cm=

f. 1 meter =

3. Which appeared first, animals or plants? What characteristics of plants enable them to survive without animals? Could animals live without plants? Explain.

4. Which of the organisms on your time line have been around the least amount of time?

5. Define and give examples of the following:

a. Primates

b. Amphibians

c. Invertebrates

6. How long did the dinosaurs live before becoming extinct? How does this compare with how long humans have been around?

a. Based on your answer above, do you think the dinosaurs were successful? Do you think humans will . be around that long? Why or why not?

Time Line Questions-MD.docx 03/15/10