1. Heredity and Adaptation Teaching Slides, 1.1
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2. Science Log Q3 week 8 Monday Feb 27:
Name one of the six extinctions and what happened or could happen.
Heredity and Adaptation Course, 1.1: The Fossil Record

3. Review vocabulary
Spend a few minutes reviewing the vocabulary for this part. Update the vocabulary index and table of contents in your notebook.
Heredity and Adaptation Course, 1.1: The Fossil Record
Step 17

4. Review vocabulary unit 1.1 page 58
Biodiversity: the variety of life that exists in a particular habitat or ecosystem.
Extinct: no longer existing.
Extinction: when the last of a species population dies out and it can no longer reproduce.
Fossil: any remains, trace, or imprint of animal or plant life preserved in Earth’s crust.
Fossil record: all the fossils on Earth
Organism: a living thing.
Paleontologist: a scientist who studies fossils
Principle of superposition: a theory that says sedimentary rocks on the bottom are older than rocks on the top.
Sediment: pieces of weathered rock such as sand, deposited by wind, water, and ice.
Sedimentary rock: a rock that forms when layers of sediments are stuck together
Tetrapod: a vertebrate with four limbs
Heredity and Adaptation Course, 1.1: The Fossil Record

5. Answer the focus question 1.1 page 55
What does the fossil record tell us about the history of life on Earth?
Use the information
That you have learned about
fossils and the fossil record.
Heredity and Adaptation Course, 1.1: The Fossil Record
Step 18

6. Draw a line of knowledge, add if needed. Should have included
The fossil record gives us evidence of organisms that lived in the past and are now extinct.
Not all organisms form fossils, so the fossil record is incomplete.
The fossil record gives us approximate ages for when organisms lived.
Heredity and Adaptation Course, 1.1: The Fossil Record

7. Heredity and Adaptation Teaching Slides, 1.2
If you are using the PowerPoint slides, log in to your FOSSweb account on your internet browser. Then, cut and paste these links into your browser.
Resources by Investigation provides access to all notebook masters, teacher masters, online activities, and video content:
The eBook provides access to all FOSS Science Resources articles:
If you are using the PDF versions of the slides, simply log in to your FOSSweb account before starting; the embedded links will take you directly to the Resources by Investigation and the eBook.
If you plan to use these slides offline, be sure to plan ahead and download the necessary duplication masters from the Resources by Investigation section of FOSSweb.

8. Discuss the fish Teacher master C, Modern Fish
What do you observe about this fish?
What inferences can you make about the fish?
Where do fish live?
In either salt of fresh water; in lakes, rivers, the ocean.
How does a fish move?
It swims using fins, moving its body side to side.
What do you notice about the structure of fish fins?
They have a number of long, think bones.
Heredity and Adaptation Course, 1.2: Transitions
Step 1

9. The Age of Fishes
Scientists think that life on Earth began in the water and continued in the water until continents emerged millions of years ago.
One of the areas of inquiry is how life made the transition (change) from water to land.
The first land animals were insects, but there is much interest about how vertebrates made that transition from water to land.
Heredity and Adaptation Course, 1.2: Transitions

10. Discuss the fish
Teacher master D, The Age of Fishes Take a few minutes and examine and generate questions about the image. This is an artist’s drawing of different fish and organisms that lived during the Devonian period, between about 419 and 359 million years ago. During this period, vertebrates started the transition from water to land.
Heredity and Adaptation Course, 1.2: Transitions
Step 1

11. Discuss the fish Teacher master D, The Age of Fishes
Why would water-dwelling fish move onto the land?
What might have caused some fish to develop legs and feet over the course of millions of years? Discuss
Where can we look for evidence about how vertebrates made the transition from water to land, from fish to animals with legs?
The fossil record
Heredity and Adaptation Course, 1.2: Transitions
Step 1

12. Focus question 1.2 page 59
What does the fossil record tell us about how life has changed over time?
Heredity and Adaptation Course, 1.2: Transitions
Step 2

13. FOSS Science Resources
You are going to look at fossils that might help tell how vertebrates made the transition from life in water to life on land. Title page 60 “From Water to Land”
Heredity and Adaptation Course, 1.2: Transitions
Step 3

14. FOSS Science Resources
Study “Transitions” on page Quickly preview the pages to see how they are arranged and look for a pattern in how the data is presented.
Heredity and Adaptation Course, 1.2: Transitions
Step 3

15. FOSS Science Resources
Study “Transitions” on page 78. Quickly preview the pages to see how they are arranged and look for a pattern in how the data is presented. Make a content grid like the one shown on page 60 and compare the different features of each of the ancient organisms.
Heredity and Adaptation Course, 1.2: Transitions
Step 3

16. FOSS Science Resources
Heredity and Adaptation Course, 1.2: Transitions
Step 3

17. Study and compare organisms
Teacher master E, Transitions: Ancient Lungfish Teacher master F, Transitions: Eusthenopteron Teacher master G, Transitions: Acanthostega
Heredity and Adaptation Course, 1.2: Transitions
Steps 4-7

18. 4. Study Ancient Lungfish
Teacher master D, The Age of Fishes
What do you notice about the fins?
Kind of fat, not like the fish we think of today.
Where did the lungfish live?
In Water
Heredity and Adaptation Course, 1.2: Transitions
Step 1

19. 5. Eusthenopteron Teacher master F, Transitions;
Turn to Eusthenopteron
Review the information on this organism and review what they have written on you content grid.
Heredity and Adaptation Course, 1.2: Transitions

20. 6. Compare ancient lungfish and Eusthenopteron
How is Eusthenopteron similar to and different from an ancient lungfish?
They’re both fish. The lungfish fins appear to be more like ray fins. Heads are both roundish; the Eusthenopteron’s eyes are higher on the head.
How are the fin structures similar and different?
Eusthenopteron doesn’t have as many bones, and they are clumped together near the body; they have a long, fleshy lobe/pad.
When did Eusthenopteron live?
380 mya
Heredity and Adaptation Course, 1.2: Transitions

21. 7. Study Acanthostega When did Acanthostega live?
360 mya
How many years are between Eusthenopteron and Acanthostega?
20 million years. This is a really long time.
Heredity and Adaptation Course, 1.2: Transitions

22. 7. Study Acanthostega
How are Acanthostega and Eusthenopteron similar and different?
Eusthenopteron has fins;
It is thought to have been completely aquatic.
Acanthostega has flipper-like limbs with fingers and no fins.
Its head seems kind of flattish, and the eyes are on top.
It had a wide tail.
It may have left the water sometimes.
Heredity and Adaptation Course, 1.2: Transitions

23. 6. Compare ancient Eusthenopteron and Acanthostega
Consider these questions,
Highlight the similarities and circle the differences in age, fins, limb structure, and body structure on your content grids.
For Eusthenopteron and Acanthostega
Heredity and Adaptation Course, 1.2: Transitions

24. 6. Compare ancient Eusthenopteron and Acanthostega
Acanthostega is one of the first known examples of what we call tetrapods.
“Tetra” means four, and “pod” means foot or limb.
So a tetrapod is a vertebrate organism with four limbs.
Humans are also tetrapods; we have four limbs: two arms and two legs.
Acanthostega had gills like a fish, and its limbs could not support weight.
Heredity and Adaptation Course, 1.2: Transitions

25. View video: Fish with Fingers
The first Acanthostega fossils were discovered in the 1930’s, but the paleontologist who found them just boxed them up and put them away.
It wasn’t until another paleontologist, Jennifer Clack, in the 1980’s found pieces of the fossils in drawers at her university in Cambride, England, that the story of this organism began to be pieced together.
As you watch think about Clack’s hypothesis about how fish made the transition to land.
Please refer to the FOSS Investigations Guide for the URL to this video.
Heredity and Adaptation Course, 1.2: Transitions
Step 8

26. View video Fish with Fingers
Please refer to the FOSS Investigations Guide for the URL to this video.
Heredity and Adaptation Course, 1.2: Transitions
Step 8

27. View video How are Dr. Clack’s ideas the same or different than yours?
Upon what evidence does she base her conclusions?
Reflect on your own hypothesis and discuss how your thinking is similar to Dr. Clark’s ideas or may have changed.
Discuss the evidence she uses for her conclusions.
Heredity and Adaptation Course, 1.2: Transitions
Step 8

28. Fish with fingers
Apparently, limbs and feet and fingers or toes appeared before vertebrates left the water as seen in Acanthostega.
They developed and were used in the water as paddles or to crawl along on the bottom.
Limbs such as these later enabled vertebrates to make the transition to land.
This is different than the earlier idea that fishes with lobed fins started moving around on land.
Record any new information on your grids.
Heredity and Adaptation Course, 1.2: Transitions

29. Study Pederpes
Teacher master H, Turn to Transitions: Pederpes Pederpes is though to be one of the first true land vertebrates. This fossil was discovered in Scotland in It was misidentified as a fish, along the lines of Eusthenopteron. In 2002, it was reclassified as a primitive land-dwelling tetrapod by Jennifer Clack.
Heredity and Adaptation Course, 1.2: Transitions
Step 9

30. Study Pederpes How long ago did Pederpes exist?
350 mya
What characteristics of Pederpes do you notice?
It has identifiable feet, no real fins at all. Its head is flat.
Why might it have those characteristics?
It may have walked on land.
Heredity and Adaptation Course, 1.2: Transitions
Step 9

31. Compare the organisms
Compare the ages, the fins, the limbs, and the body structures of all four organisms. Look for clues about what kinds of environments the organisms lived in and how the fossil record helps tell how vertebrates transitioned from water to land.
Make sure you draw the time line on the board so you can record students’ information and complete the time line for the entire class.
Heredity and Adaptation Course, 1.2: Transitions
Step 10

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Photo credits:
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Notebook image: © photastic/Shutterstock
Heredity and Adaptation Course, 1.2: Transitions