30
Examining the Fossil Record

Examining the Fossil Record

  • Upload
    monet

  • View
    41

  • Download
    0

Embed Size (px)

DESCRIPTION

Examining the Fossil Record. Lab Investigation: Fictional genus Crustaceous. Objectives : * Analyze characteristics of fossils * Compare placement of fossils and determine relative ages * Develop a model evolutionary tree based on the morphology and age of fossils. - PowerPoint PPT Presentation

Citation preview

Page 1: Examining the  Fossil Record

Examining the Fossil Record

Page 2: Examining the  Fossil Record
Page 3: Examining the  Fossil Record
Page 4: Examining the  Fossil Record

Lab Investigation: Fictional genus Crustaceous

Page 5: Examining the  Fossil Record

Objectives:* Analyze characteristics of fossils* Compare placement of fossils and determine relative ages* Develop a model evolutionary tree based on the morphology and age of fossils

Page 6: Examining the  Fossil Record

Fossils are traces of organisms that lived in the past.

When fossils are found, they are analyzed to determine the age of the fossil.

The absolute age of the fossil can be determined though radiometric dating and determining the layer of rock in which the fossil was found. Older layers are found deeper within the earth than newer layers.

Page 7: Examining the  Fossil Record

The age and morphologies (appearances) of fossils can be used to place fossils in sequences that often show patterns of changes that have occurred over time.

This relationship can be depicted in an evolutionary tree, also known as a phylogenetic tree.

Page 8: Examining the  Fossil Record

There are two major hypotheses on how evolution takes place: gradualism and punctuated equilibrium.

Page 9: Examining the  Fossil Record

Gradualism suggest that organisms evolve through a process of slow and constant change.

Example: an organism that shows a fossil record of gradually increased size in small steps, or an organism that shows a gradual loss of a structure.

Page 10: Examining the  Fossil Record

Punctuated equilibrium suggests that species evolve very rapidly and then stay the same for a large period of time. This rapid change is attributed to a mutation in a few essential genes.

Page 11: Examining the  Fossil Record
Page 12: Examining the  Fossil Record

Procedure:1a) Obtain lab instructions1b) The CHART you are

drawing requires a poster2. Use a ruler to draw the lines

on your chart.

Page 13: Examining the  Fossil Record
Page 14: Examining the  Fossil Record

Procedure:3. Obtain a

fossils sheet.

4. Cut each fossil, but leave the age of the fossil.

Page 15: Examining the  Fossil Record

5. Begin arranging the fossils by age on your chart.

6. Lower means “older” fossils, and “upper” means most recent fossil.

Page 16: Examining the  Fossil Record

Not all fossils are represented, illustrating the incompleteness of any fossil record.

Page 17: Examining the  Fossil Record
Page 18: Examining the  Fossil Record

8. If you have several fossils from the same period, place them by age order.

Montanian

170000

Page 19: Examining the  Fossil Record

9. While keeping the fossils in the proper age order, arrange them by morphology (appearance):

Montanian

170000

Page 20: Examining the  Fossil Record

Montanian

170000

10. Once all the fossils have been placed correctly according to time and morphology, glue the fossils in

place.

Page 21: Examining the  Fossil Record

11. You need to graph your poster’s chart results!

Page 22: Examining the  Fossil Record
Page 23: Examining the  Fossil Record

Poster and Graph Results should match!

Page 24: Examining the  Fossil Record

The number 0 on the Change in Morphology shows the appearance of the original (oldest) fossil. Each tick mark to either side denotes one fossil to the next-youngest fossil according to your poster results.

Page 25: Examining the  Fossil Record
Page 26: Examining the  Fossil Record
Page 27: Examining the  Fossil Record

Get a 2nd sheet of fossils to create a drawing of an evolutionary tree on your graph paper.

25 20 15 10 5 0 5 10 15 20 25

Page 28: Examining the  Fossil Record

Example of Phylogenetic Tree

Page 29: Examining the  Fossil Record

Grading:

Your 11 answers are worth 20 points each!

Your graph is worth 100 pointsYour poster is worth 75 points

Page 30: Examining the  Fossil Record

Analysis1. Give a brief description of the evolutionary changes that occurred in Crustaceous. Refer back to the morphology of Crustaceous and use the terms used to describe the various body parts of the organism that have evolved.2. During which period did the fossils start to differentiate into two branches?3. How long did it take to differentiate into two branches?4. In what period does the common ancestor of the Crustaceous species of the Montanian period appear?Conclusions:1) No examples of Crustaceous survive today. Determine when the genus became

extinct. Support your answer.2) What did scientists use to determine the absolute age of the fossils found?

Explain the process.3) Did the set of fossils show gradualism or punctuated equilibrium? Explain.4) Using Crustaceous, sketch an example of an evolutionary tree that shows

punctuated equilibrium.5) What is a fossil?6) What do scientists do to categorize fossils?7) Why is the fossil record evidence for evolution?