Chapter 14 Lesson 2, "What Fossils Show"

Materials:

• Fossils Crossword Puzzle

Objective:

• Students will explain how some fossils form.
• Students will give examples of information learned from fossils.
• Students will discuss how scientists determine the age of fossils.

Anticipatory Set:* Show the students several fossils found near Bishop mountain and describe what things might be learned by looking at the fossils. Show the students a five picture set of fossils and have them explain what they see in each picture and what scientists might learn from the picture.

Fossil1, fossil 2, fossil 3, fossil 4, fossil 5. Bog Deer interpretation.

Teacher Input:* Ask, "How do fossils happen?" Explain that there are three main ways, a cast fossil,(explain the terms mold, cast, and sediment), an animal trapped in a material like amber or ice, or preserved evidence such as solid waste or footprints.

What do you call a scientist who studies life in the past? Scientists study the fossil record for much information. They can tell what an ancient ecosystem might have looked like. If the study many different layers of rock they can tell how organisms may have changed over time. Using the fossil record scientists have put together the geologic time scale you find in your book on P360. (here is a more colorful one)

How do we know how old fossils are? The easiest way is through relative dating. Compare fossils with those above or below it. (relative dating) Scientists have also figured out how to find the actual age of though a process measuring radioactive material or radiocarbon dating, chart of radiocarbon dating.

Are dinosaurs the only extinct animals? In the fossil record there are many periods of mass extinctions.

How does the fossil record support the idea of evolution? Explain how the different fossils of a horse-like animals show that the horse has changed over 60 million years. (P362)

Does the fossil record show any organisms that may be a combination of two or more organisms alive today? Can you name one of those fossils? Explain the Archaeopteryx. 1, 2, 3

Compare the Archaeopteryx to the dinosaur and the bird.

Guided Practice:* Go through the questions on P365 with the students.

Independent Practice:* Students will work on the Fossils Crossword Puzzle

Check for Understanding:* Students will take a quiz on lesson 2, What Fossils Show.

Duration:

30 minutes + 10-15 for Independent Practice (Could be longer if taken for homework).

Alaska Content Standards Addressed in this lesson:

• SCI A-12 Students will distinguish the patterns of similarity and differences in the living world in order to understand the diversity of life and understand the theories that describe the importance of diversity for species and ecosystems.
• SCI A-13 Students will understand the theory of natural selection as an explanation for evidence of changes in life forms over time (Evolution and Natural Selection).

• SCI A-15 Students will use science to understand and describe the local environment (Local Knowledge); and:
• SCI C- 8. understand that acceptance of a new idea depends upon sup- porting evidence and that new ideas that conflict with beliefs or common sense are often resisted.
• SCI D- 1. apply scientific knowledge and skills to understand issues and everyday events;
• SCI D- 5. participate in reasoned discussions of public policy related to scientific innovations and proposed technological solutions to problems;