Evidences for Evolution

Warm Up Put the following steps of natural selection in order: Write your statements in the warm up section. A. There is a limited supply of resources necessary for life. B. The organisms with favorable adaptations survive, reproduce, and pass on their alleles. C. Changing environments select for specific phenotypes. D. Populations are genetically variable due to mutations and genetic recombination. E. The accumulation of favored alleles leads to a change in species over time.

Warm Up – Check your answers and correct if necessary D A C B E

Objectives- Record in the objectives section. Identify four evidences for evolution. Provide examples of how each type of evidence supports change over time (evolution).

Tech Manager - Read the following to your group: Background When Charles Darwin first proposed the idea that all new species descend from an ancestor, he performed an exhaustive amount of research to provide as much evidence as possible. Today, the major pieces of evidence for this theory can be broken down into the fossil record, embryology, comparative anatomy, and molecular biology.

Station Specifics: For each of the following evidences for evolution, complete the tasks given on each slide. Write the answers to the guiding questions in complete sentences.

Evidence I - Fossils: Study this table and proceed to the next slide.

Fossils: Guiding Questions – Answer on your handout. 1. Give two similarities between each of the skulls that might lead to the conclusion that these are all related species. 2. What is the biggest change in skull anatomy that occurred from the dawn horse to the modern horse? 3. What is the biggest change in leg anatomy that occurred from the dawn horse to the modern horse?

Evidence II - Embryology. Organisms that are closely related may also have physical similarities before they are even born! Take a look at the six different embryos below: Source: http://www.starlarvae.org Hypothesize which embryo is from each of the following organisms: Record your answers on chart A provided on your template. Species Embryo Human Chicken Rabbit Tortoise Salamander Fish

Embryology: These are older, more developed embryos from the same organisms. Hypothesize which embryo is from each of the following organisms: Record your answers on chart B provided On your template. Species Embryo Human   Chicken Rabbit Tortoise Salamander Fish

Embryology:

Embryology: Guiding Questions- Answer on your handout. 1. Look again at the six embryos in their earliest stages. Describe the patterns you see. What physical similarities exist between each of the embryos? 2. Does this suggest an evolutionary relationship? Explain how these embryos can be used as evidence of a common ancestor between each of these six organisms.

Evidence III- Comparative Anatomy Compare the skeletal structure of each limb to the human arm. Relate the differences you see in form to the differences in function. Animal Comparison to Human Arm in Form Comparison to Human Arm in Function Whale Whale has a much shorter and thicker humerus, radius, and ulna. Much longer metacarpals. Thumb has been shortened to a stub. The whale fin needs to be longer to help in movement through water. Thumbs are not necessary as the fins are not used for grasping. Cat   Bat Bird Crocodile

Comparative Anatomy: Guiding Questions- Answer on your handout.

Comparative Anatomy: Guiding Questions- Answer on your handout.

Comparative Embryology: Vocabulary- Write the definitions on your handout. SUMMARY: You have now studied three different types of anatomical structures:  Homologous structures show individual variations on a common anatomical theme. These are seen in organisms that are closely related.  1. Give an example of a homologous structure from this activity: ______________________  Analogous structures have very different anatomies but similar functions. These are seen in organisms that are not necessarily closely related, but live in similar environments and have similar adaptations.  2. Give an example of an analogous structure from this activity: ______________________  Vestigial structures are anatomical remnants that were important in the organism’s ancestors, but are no longer used in the same way.  3. Give an example of a vestigial structure from this activity: _______________________  

Answers to Vocabulary Work Front limbs of animals Bird and butterfly wing Eyes of a cavefish

Comparative Anatomy Below are some vestigial structures found in humans. For each, hypothesize what its function may have been and Record the answers on your handout. Structure Possible function? Wisdom teeth   Appendix Muscles for moving the ear Body hair Little toe Tailbone How are vestigial structures evidence for evolution?

RESULTS TABLE: 58 60 61 62 63 64 65 66 100 101 102 103 104 Human I G E   58 60 61 62 63 64 65 66 100 101 102 103 104 Human I G E D T L M K A N Chicken S Horse Tuna V R - Frog C Shark Q Turtle Monkey Rabbit RESULTS TABLE: Animal Number of Amino Acid Differences Compared to Human Cytochrome C Horse   Shark Chicken Turtle Tuna Monkey Frog Rabbit

Molecular Biology: Guiding Questions 1. Based on the Cytochrome C data, which organism is most closely related to humans? 2. Do any of the organisms have the same number of differences from human Cytochrome C? In situations like this, how would you decide which is more closely related to humans?

Watch the following video on Charles Darwin’s work. https://www.youtube.com/watch?v=2k2UxiHREUM

Summary Questions- Work Independently 1. Charles Darwin published his book On the Origin of Species in 1859. Of the different types of evidence that you have examined, which do you think he relied upon the most, and why? 2. Given the amount of research and evidence available on evolution, why is it classified as a theory?

You Try – Match the following examples with the type of evidence for evolution. You may use an evidence more than once. Check your work on the following slide. Amino acid sequences are 98% similar in a protein from a chimpanzee and human The number of base pairs in human and chimpanzee DNA is remarkably similar The appendix of humans is not fully functional, but the appendix of a rabbit is The shells of certain ocean invertebrates has become more circular and intricate over time The embryos of chicken, humans, and pigs all have a tail and gill slits in the throat region COMPARATIVE ANATOMY MOLECULAR EVIDENCE FOSSIL EVIDENCE EMBRYOLOGY

You Try – Answers A- Molecular B-Molecular C- Comparative Anatomy D- Fossils E- Embryology

Fossil evidence Embryology Comparative Anatomy Molecular Evidence Quick Review: Each person at your table should explain how each evidence shows a CHANGE IN ORGANISMS OVER TIME! Fossil evidence Embryology Comparative Anatomy Molecular Evidence

Practice your explanations from the last slide. Be ready to explain how each evidence presented today shows a change over time. Call your instructor over. Your instructor will call on a random group member and you will all receive credit for the member’s response.

Goin’ To The Next Level Now, let’s take what you’ve learned and try your skills at a game. Find another group to compete against One of you should go to the front of the room and get a pile of questions.

Let’s compete… Obtain the stack of multiple choice questions. Some are on what you’ve learned today and some are on what you’ve learned earlier in this unit. Going in a rotation type pattern, each person will choose a card from the stack. Hand the card to another group member, and they will read the card aloud to you. Answer the question. The person reading will turn the card over for the correct answer. If you are correct, you will Spin the Big Wheel in the game that follows. Which member will get the most points??

The Big Wheel Play

The Big Wheel Team Scores Spin Wheel Points Team One Team Two Team Three Team Four Team Five Team Six Team Seven Team Eight Spin Wheel Points

Homework: Vocab Sheet up front ------- DUE TUESDAY: TAKE HOME TEST WEDNESDAY: VOCAB