Cladogram of seven animal speciesMolecular Evidence of Evolution – Cytochrome-C Intro: Cytochrome-C, an enzyme found in virtually all organisms, is needed for the release of energy from food. The amino acid sequences in this protein from several different organisms are compared in the diagram that follows. The differences between these amino acid sequences can be used to infer the relatedness of the organisms. Procedure: 1. Find the human, rhesus monkey, kangaroo, snapping turtle, bullfrog, and tuna on the “Amino Acid Sequences in Cytochrome-C Proteins from 20 Different Species” chart provided. 2. Compare the human amino acid sequence to each of these five animals by counting how many amino acids in that animal’s cytochrome-c are different from those in the human protein. Record the number of differences between humans and each species in the table below. Number of differences between humans and other species in cytochrome-c protein Species Rhesus monkey Kangaroo Snapping Turtle Bullfrog Tuna Amino Acid Differences 3. A cladogram is a graphical means of showing the relatedness of species based upon shared traits. The branching nature of the cladogram is reflective of the branching nature of evolution. The point where two evolutionary lines meet represents the most recent ancestor that they share in common. The cladogram below shows the relatedness of several animals based upon anatomical similarities. For example, out of seven key traits, all of these animals have a dorsal nerve cord. We can infer that these animals all share a distant common ancestor that also had a dorsal nerve cord. Only humans, monkeys, and kangaroos have mammary glands. We can infer that they alone share a common ancestor that also had mammary glands. Cladogram of seven animal species lamprey tuna bullfrog turtle kangaroo monkey human Placenta Mammary glands Amnion (fluid-filled sac that surrounds developing fetus) Paired legs Paired appendages + spinal column Dorsal nerve cord + notochord 4. Record the number of differences you measured between the different amino acid sequences of the cytochrome-c protein in the cladogram below. Write your answers in the circles below each arrow. lamprey tuna bullfrog turtle kangaroo monkey humanAnalysis: ANSWER THE FOLLOWING QUESTIONS AND HAVE THEM WITH YOU BEFORE ATTEMPTING THE MOODLE ASSIGNMENT! 1. Does the data from the amino acid sequence generally agree with the anatomical data that was used to construct the cladogram? (yes/no) 2. Do organisms with fewer shared anatomical traits also have more differences in their proteins? (yes/no) 3. Compare the cytochrome c amino acid sequences of ducks to that of chickens/turkeys (How many differences are there?) What conclusion(s) can we make about the ancestry of humans and monkeys compared to ducks and chickens? Choose all that apply: A. Monkeys and humans share a more recent common ancestor than the duck and chicken. B. Chickens and ducks share a more recent common ancestor than the monkey and human. C. There has been more time for the duck and chicken lines to accumulate mutations. D. There has been more time for the monkey and human lines to accumulate mutations. E. Ducks and chickens are more closely related than monkeys and humans. 4. The cytochrome c amino acid sequence of the penguin has 3 differences from the duck and 2 differences from the chicken/turkey. The mutation at amino acid # _____ most likely occurred in the most recent common ancestor of penguins and chickens. A. 111 B. 100 C. 43 D. 11 5. The mutation at amino acid # _____ most likely occurred after penguins had diverged from the other birds. A. 111 B. 100 C. 43 D. 11 Look carefully at amino acid #111. 6. What would you assume to be the amino acid at 111 in the bird/reptile common ancestor? 7. When did the mutation in ducks occur? 8. What would you assume to be the original amino acid in mammals at 111? 9. Which mammal has recently experienced a mutation at 111? 10. Suppose someone asked you to show them how cytochrome c illustrates the closer relationship of humans to monkeys than to other mammals. Which of these amino acids would you point out? A. 19 B. 55 C. 66 D. 70 E. 100 11. The last three species on the chart are fungi. Construct a cladogram of these fungal species that shows their relatedness based upon differences in the cytochrome-c protein. Species should be grouped together on the same branch of the cladogram if they have fewer differences and share more similarities in the cytochrome-c sequence. # differences: Sac/Baker’s: 42 Sac/Candida: 44 Baker’s/Candida: