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Bio 9D: Thursday, 4.28.11 Title: Evidence for Evolution. Homework: None Silent Do Now: (in NB w/ title and date) As you know, different organisms are related to each other through evolutionary history – this means that they share a common ancestor.
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Bio 9D: Thursday, 4.28.11 Title: Evidence for Evolution • Homework: • None • Silent Do Now: (in NB w/ title and date) As you know, different organisms are related to each other through evolutionary history – this means that they share a common ancestor. • What are some species that you think are close evolutionary relatives of humans? What are some more distant evolutionary relatives of humans? • Today’s Objectives: • Explain the 3 types of homologies and use them as evidence to build evolutionary trees.
Evolution Dry Lab Part A Part A Computer Lab All in the Family: Which Animals are the Closest Relatives? Link: http://www.pbs.org/wgbh/evolution/change/family/index.html The purpose of this series of lab activities is for you to… • Examine and understand the evidence for evolution • Use that evidence to infer evolutionary relationships and build phylogenetic trees • Part A focuses on using the three different types of homologies as evidence for evolutionary relationships • Objectives for Class: • Use the three different types of homologies as evidence for evolutionary relationships
EVIDENCE FOR EVOLUTION What is the evidence that all species on earth are related to each other and share common ancestors? Overview: 3 Major Types of Evidence: • Homologous Structures • Anatomical homologies and vestigial structures • Embryological/ Developmental • Molecular/Genetic • Fossils • Geographic Distribution of Species • Objectives for Class: • Describe the three different types of homologies and give examples of each
HOMOLOGOUS STRUCTURES – Similar structures due to sharing a common ancestor that had those structures • Objectives for Class: • Describe the three different types of homologies and give examples of each
Anatomical Homology – similar body parts or bone structures • Don’t necessarily have the same function now, but did in the common ancestor • Ex: human arm, cat leg, whale flipper, bat wing all have same bones • Objectives for Class: • Describe the three different types of homologies and give examples of each
Anatomical Homology, continued: Vestigial Traits - • Don’t have a function now, but suggest that they descended from an ancestor that did use them. • Examples: • human tailbone, human goose bumps, ostrich wingsEx: human tail bone, human goose www.toptenz.net • Objectives for Class: • Describe the three different types of homologies and give examples of each animal.nationalgeographic.com
Embryological/Developmental Homology Similar characteristics appearing during specific embryonic/ developmental stages of development • Examples: • fish, reptile, bird, and human embryos all have gill slits and a tail (but some lose these features before birth) • Objectives for Class: • Describe the three different types of homologies and give examples of each
Molecular/Genetic Homology • Similarities between DNA or amino acid sequences for different organisms • Closer the similarities = Closer relationships • Objectives for Class: • Describe the three different types of homologies and give examples of each
Don’t confuse Homologous Structures with Analogous Structures • Analogous Structures • structures that have the same function but NOT the same skeletal structure • This suggests these organisms did NOT descend from a common ancestor with that trait Ex: insect wing and bird wing Bird wing Insect wing • Objectives for Class: • Describe the three different types of homologies and give examples of each bio.miami.edu
Evolution 3-Part Investigation Dry Lab Key Questions: • What is the evidence that one species can branch into two? • What is the evidence that multiple species are evolutionarily related? • Objectives for Class: • Use the three different types of homologies as evidence for evolutionary relationships
Phylogenetic Tree for All Living Things Time -------------------------------------------------------------------->present Nodes indicate most recent common ancestor of two branches
Bio 9A: Monday, 5.3.10 Title: Evidence for Evolution: Anatomy vs. Molecular Evidence • Homework: • Lab Part B: Finish Tree #1 and Analysis Question #6 by tomorrow • Finish the whole lab packet by Thursday – you’ll have tomorrow class time plus HW time (but you have Exhibition Night Tuesday night) • Do Now: • According to this diagram, which organism is the closest evolutionary relative of a bat? • What is one piece of evidence you could use to explain this evolutionary relationship? • Today’s Objectives: • Compare and contrast anatomical and genetic homologies as evidence for evolution Bird Bat Mouse
Evolution Dry Lab PART B – Day 1 Part B: Comparing Anatomical and Genetic Evidence The purpose of this series of lab activities is for you to… • Examine and understand the evidence for evolution • Use that evidence to infer evolutionary relationships and build phylogenetic trees • Part B focuses on comparing and contrasting anatomical and genetic homologies as evidence for evolution Tasks for Today: • Complete the pre-lab questions • Complete the Data Chart for Tree #1 • Use the chart to build an evolutionary tree for 7 animals based on anatomical traits • Objectives for Class: • Compare and contrast anatomical and genetic homologies as evidence for evolution
Bio 9A: Tuesday, 5.4.10 Title: Evidence for Evolution: Anatomy vs. Molecular Evidence (Day 2) • Homework: • Lab Part B: Finish the packet and all analysis questions (typed up and stapled to the packet) • Good luck at exhibition night tonight! • Do Now(s): • Take out Lab Part B packet and turn to the page with the amino acid sequences • Get a marker and highlight the human sequence on both rows • We will count off (monkey, kanga, frog, turtle, tuna). Highlight both rows of your assigned organism. • Today’s Objectives: • Compare and contrast anatomical and genetic homologies as evidence for evolution
Evolution Dry Lab PART B – Day 2 Part B: Comparing Anatomical and Genetic Evidence The purpose of this series of lab activities is for you to… • Examine and understand the evidence for evolution • Use that evidence to infer evolutionary relationships and build phylogenetic trees • Part B focuses on comparing and contrasting anatomical and genetic homologies as evidence for evolution • Objectives for Class: • Compare and contrast anatomical and genetic homologies as evidence for evolution
Bio 9A: Thursday, 5.6.10 Title: Evidence for Evolution, continued! Double Block Homework: • Complete Lab Part C up to Task 5 and type your response to question 1 for the analysis questions – completed lab is due Monday! Do Now: • Pass Part A and B forward and take out Part C • Look back in your notes… • What are the 3 types of homologies that can be studied as evidence for evolution? • What are two types of evidence for evolution besides homologous structures? • Today’s Objectives: • Describe how fossils are used as evidence for evolution and give one example that illustrates this. • Describe how the geographic distribution of species is used as evidence for evolution and give one example that illustrates this.
Review: EVIDENCE FOR EVOLUTION • Homologous Structures • Anatomical homologies and vestigial structures • Embryos • Molecular/Genetic • Geographic Distribution of Species • Fossils
Recap: Analogy vs. Homology • Homologous Structures – similar structures due to shared ancestry • common ancestor had this feature, so all descendents have it • Results from divergent (branching) evolution • Example: • Analogous Structures – similar structures due to natural selectionin similar environments • common ancestor did not have it, but descendents evolve it independently • Example:
Evidence for Evolution, continued: Geographic Distribution
Evidence: GEOGRAPHIC DISTRIBUTION • Species that live on the same continents are often closely related to each other • Based on genetic (DNA) and embryonic evidence • This is true, even thoughthey look more similar to species elsewhere. Example: North vs. South American rodents • Objectives for Class: • Describe how fossils are used as evidence for evolution and give one example that illustrates this.
Evidence: GEOGRAPHIC DISTRIBUTION Example: Placental Mammals vs. Australian Marsupial Mammals • Australia has been separated from other continents for a long time, so its marsupials evolved independently • Marsupial traits are analogous, NOT homologous, to placental mammals
Evidence for Evolution Fossils
Evidence: FOSSILS • Fossils • show species that are now extinct • show transitions to new body forms • Example: Tiktaalik (lived 375 million years ago) • fish with legs and (maybe) primitive lungs… • earliest amphibian? • Objectives for Class: • Describe how fossils are used as evidence for evolution and give one example that illustrates this. Artist Rendering Fossil
Evidence: FOSSILS cont. • Example: Archaeopteryx (lived 150 million years ago) • earliest bird… but has many dinosaur features • Objectives for Class: • Describe how fossils are used as evidence for evolution and give one example that illustrates this. www.ansp.org
Evidence: FOSSILS cont. • Interpreting Fossil Evidence • Fossils form in layers of rock (older = lower layer) • Fossils in the same layer lived at the same time • Radiometric dating: determine the age of a fossil based on how much radioactive carbon it contains • Objectives for Class: • Describe how fossils are used as evidence for evolution and give one example that illustrates this.
What lived at the same time as the fossil fish? • Objectives for Class: • Describe how fossils are used as evidence for evolution and give one example that illustrates this.
Evidence for Evolution: Part C How did whales evolve?
Evolution Dry Lab PART C – Day1 Part C: How Did Whales Evolve? The purpose of this series of lab activities is for you to… • Examine and understand the evidence for evolution • Use that evidence to infer evolutionary relationships and build phylogenetic trees • Part C focuses on using fossil evidence and anatomical homologies to determine evolutionary relatedness • Today: Complete Tasks 1-4 • Then we will watch this video: http://www.pbs.org/wgbh/evolution/library/03/4/l_034_05.html • Objectives for Class: • Describe how fossils and anatomical homologies are used as evidence for evolution
Ambulocetusnatans in action A reconstruction of an early close cousin of whales Shown here with the kind permission of artist Carl Buell. http://www.indiana.edu/~ensiweb/lessons/whale.ev.html
Bio 9A: Friday, 5.7.10 Title: Using fossils and homologous structures as evidence for evolution • Homework: • Finish Typing the analysis question for Part C. Completed lab is due Monday. • Do Now: • Take out Part C and turn to the timeline page (Task 4) • Get ready to check your answers and write dates on your official timeline! • Today’s Objectives: • Describe how fossils are used as evidence for evolution and give one example that illustrates this. • Explain how whales evolved from land mammals.
Task 5: Draw the phylogenetic tree! • Draw your tree… • Which organisms go on the 3 branches that reach the “top” of the tree? • Which organism goes on the lowest branch? • Fill in the rest on your own AFTER the video Land mammal ancestor
Evolution Dry Lab PART C – Day2How Did Whales Evolve? • Watch the video and take notes: http://www.pbs.org/wgbh/evolution/library/03/4/l_034_05.html • Finish Task 5: Making the phylogenetic tree • For the rest of class: 3 options. • If you did not complete the analysis questions for Part B, meet in the front of the room. • If you want to do the Part C analysis questions in your notebook working with a partner/small group, go to the back of the room. • If you want to do the Part C analysis questions silently on your own, you may do so (ipods okay for this group only). • Objectives for Class: • Describe how fossils and anatomical homologies are used as evidence for evolution
Bio 9A: Monday, 5.10.10 Title: Evolution Review & Wrap-Up • Homework: • Study for tomorrow’s “Tuiz” • Do Now: • Pass Lab Part C to the middle of the row (packet AND analysis q’s) • Look at the grade report and stack of graded work that is being handed back. • In your notebook: Write at least one thing you need to complete, revise, or review (for tomorrow’s test) in order to do your best in this class. • Today’s Objectives: • Tuiz Review: • Explain how populations change over time through natural selection. • Explain the different types of evidence for evolution. • Draw and interpret evolutionary trees.
Tasks for Today: • Work silently on your own • Make a review section in your notebook and make review notes based on the study guide • Complete the practice multiple choice questions • Review all assignments handed back Mr. Moretti has office hours this afternoon if you want to study more with him!
EVOLUTION SUMMARY • Populations of living things change over time. • Due to change over time, a species can evolve into one or more new species. This results in the branching view of the tree of life. • All living things are related because we all evolved from a common ancestor.
Phylogenetic Tree for All Living Things Time -------------------------------------------------------------------->present “There is grandeur in this view of life…” – Charles Darwin
Bio 9A: Tuesday, 5.11.10 Title: Evolution “Tuiz” • Homework: • None • If you know you are missing work or need to revise – do that!! • Do Now: • Take out a pen or pencil and clear your desks • Today’s Objectives: • Show what you know about evolution on the “Tuiz”