EVIDENCE TYPE #1

Obtaining Information from Fossils

Fossils may provide information that goes beyond size and shape of organisms. Information from fossils may also include how organisms interact with each other - both within species and between species.

1. a. Examine the footprints (A) on the back of this page. What can be inferred from the evidence? Include all hypothesis. b. What questions do you have about these organisms?

2. Fossils can also provide information about how organisms change throughout the ages. Examine the chart (B) that shows the evolution of the modern horse from an early ancestor.

a. How does the placement of fossils in rock layers help to age fossils? Use an example from the chart to support your answer.

b. Note the changes in the forefeet of the horse. Summarize how the bones evolved.

A. B.

EVIDENCE TYPE #1 (cont’d)

The original fossil record was only able to provide “snapshots” of ancestral forms of animals. However, the ongoing discovery of hundreds of transitional fossils provides intermediary links.

1. View the video online that shows the evolution of the whale. View to approximately 1:30 min a. When you view the transitional fossils showing the evolution of the whale, what structural

changes are evident with hind bones and the nostril? b. What does vestigial mean? What is the significance of presence of vestigial structures to

evolution?

2. View the rest of the video starting at approximately 1:30 minutes. a. Astonishingly, evidence shows that hippos and whales are related!! Does this mean that

hippos evolved from whales or vise versa? Explain. b. What two groups of evidence supports the fact that whales and hippos are related?

As a group, summarize the information you have learned about EVIDENCE #1.

Evidence #2

A. View the video on our website. Using information from the video explain the following in your own words: 1. Why do species on islands tend to be different from close species found on mainlands?

You may wish to refer to Darwin’s finches in your explanation (see back of sheet). 2. Why can species on different continents be closely related?

B. The Island of Madagascar is thought to have split from Africa about 150 million years ago. Madagascar is home to many unique organisms. View the page (linked on the website) to admire just a few of them. 3. Select two of these organisms and suggest some features of the island that were present and/or what features were absent from the island to cause these unique species to evolve.

Evidence #3

Embryology is the study of an organism’s development. Embryology has been used to determine evolutionary relationships as the embryos of different organisms exhibit similar stages of development.

1. Look at the images on the back of this card and identify some similarities and differences among the organisms.

2. View the video that animates the development of human embryos. a. What stages of the human embryo provide evidence of a common ancestor? Provide

three stages of embryonic development to support this hypothesis. b. What is one piece of chemical evidence that supports a common ancestor?

3. Why might some of the early stages of embryo development still be so similar among different organisms?

Evidence #4

A. Homologous Structures - structures that have similar structural elements and origin but may have different function.

1. Look at the image on the back of this card (or the colour version on the website). What do you notice about the bones of the forelimbs? 2. Select two of the species and suggest why the bones adapted to the particular shape given how the particular forelimb functions for the organism (eg., horse forelimb is uses for walking and bearing the weight of the animal).

B: Analogous Structures - structures of organisms that do not have a common evolutionary origin but now perform similar functions.

3. Butterfly wings and bird wings are analogous structures. Explain this statement.

4. Create a T-chart to compare homologous and analogous structures.

Evidence #5

BEFORE: 1. What do you know about DNA & protein that you think may support the fact that

organisms on Earth arose from the same common ancestor?

DURING: View the video on illustrates evidence from DNA. As you view, consider what evidence there is that we all arose from a common ancestor.

AFTER:

2. What astonishing facts about DNA & proteins support the “Theory of Evolution”? Do these facts astonish you? Explain.