Station 1 DNA Evidence

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Magdalene Manning
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1 Station 1 DNA Evidence Cytochrome-c is a protein found in the mitochondria that is used in cellular respiration. This protein consists of a chain of 104 amino acids. The chart below shows the amino acid sequence for cytochrome-c of five vertebrates. Animal Amino Acid Sequences in Cytochrome-C Horse gln pro phe thr thr ala lys asn lys thr lys glu glu thr leu met glu lys ala thr asn glu Shark gln gln phe ser thr asp lys ser lys thr gln gln glu thr leu arg ile lys thr ala ala ser Human gln pro tyr ser thr ala lys asn lys ile gly glu asp thr leu met glu lys ala thr asn glu Turtle gln glu phe ser thr glu lys asn lys thr gly glu asp thr leu met glu asp ala thr ser lys Monkey gln pro tyr ser thr ala lys asn lys thr gly glu asp thr leu met glu lys ala thr asn glu 1. Compare the amino acid sequence of human cytochrome-c with that of the other four vertebrates. For each vertebrate, count the number of amino acids that differ from those in the human. Write the number in the data table on your student page. Then answer the questions below the data table on your student page. 2. Based on the data, list the order in which these vertebrates are related to humans using the data table on your student page. Place the vertebrates more similar to humans in sequence from the top.

2 thr Station 2 Embryology Can you tell a chicken from a fish? How about a human from a pig? Sure you can, you say. Chickens have wings, fish have fins, humans have arms and pigs have hoofs. But what about when they are just starting to form? The drawings below represent three developmental stages of five different animals. They have been all mixed up -- see if you can tell what's what. Procedure 1. Arrange the squares with your group members and see if you can correctly match the embryos with the animals, placing them in order from earliest to latest stages of development. 2. Fill in the chart on your student page with the number that is on the card. 3. Answer the questions below the chart on your student page.

3 Fish Chicken Pig Calf Human

4 Station 3 Homologous Structures Procedure: 1. Color the homologous bones on your student page according to the color scheme below: Green = humerus Red = radius Blue = ulna Yellow = metacarpals Purple = phalanges 2. Answer the questions on your student page.

5 Station 4 Fossils

6 Station 5 Phylogenetic Trees A phylogenetic tree is a diagram that depicts the lines of evolutionary descent of different species, organisms, or genes from a common ancestor. The trees have branches, the length of which is proportional to the hypothesized time between the divergence of the organisms. Each node at the fork represents a common ancestor. 1. Look at organisms B, C, and D. These are organisms that can be found in present time. Sequence the common ancestors shown from oldest to most current. 2. Look at organisms B and C. They share three common ancestors, X, A, and Z. How many common ancestors do organisms D and B share? 3. Which of the present day organisms are the most closely related?

7 Station 6 Cladograms What is a cladogram? It is a diagram that depicts evolutionary relationships among groups. It is based on phylogeny, which is the study of evolutionary relationships. Cladistics form of analysis that looks at features of organisms that are considered "innovations", or newer features that serve some kind of purpose. (Think about what the word "innovation" means in regular language.) These characteristics appear in later organisms but not earlier ones and are called derived characters. Procedure 1. Examine the sample cladogram, each letter on the diagram points to a derived character, or something different (or newer) than what was seen in previous groups. Match the letter to its character on your student data sheet. Note: This cladogram was created for simplicity and understanding, it does not represent the established phylogeny for insects and their relatives. 2. To make a cladogram, you must first look at the animals you are studying and establish characteristics that they share and ones that are unique to each group. For the animals on the table, indicate whether the characteristic is present or not. Create a cladogram like the one pictured above. (Write the name of the organism only. You do not need to draw a picture of the organism. Replace the letters with the characteristic.) Slug (snail) Catfish Frog Tiger Human Cells Backbone Legs Hair Opposable Thumbs

8 Station 7 Biogeography Biogeography is the study of the distribution of species across the globe. Scientists refer to biogeography as evidence of evolution. Species that developed from a common ancestor are usually found geographically near each other. Procedure: 1. Compare the appearance of the six penguins. Record your observations in the data table on your student handout. 2. Write the letter for each penguin on the map according to their given latitude and longitude. 3. Answer the questions that follow on your student data sheet.

10 A. African penguin (35 S, 25 E) D. Chinstrap Penguin (180 W, 80 S) B. Galapagos penguin (10 S, 90 W) E. Adelie Penguin (120 E, 65 S) C. Humboldt penguin (75 W, 15 S) F. Gentoo Penguin (30 E, 70 S)

Amino Acid Sequences and Evolutionary Relationships. How do similarities in amino acid sequences of various species provide evidence for evolution?

Amino Acid Sequences and Evolutionary Relationships Name: How do similarities in amino acid sequences of various species provide evidence for evolution? An important technique used in determining evolutionary