Natural selection - an introduction
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The document outlines a biology lesson on natural selection. It begins with questions for students about the candy they selected and why. It then discusses how natural selection works in nature by individuals having different traits, with some traits helping organisms survive and reproduce while others do not. Observations from nature that can be explained by natural selection are mentioned, like homologous structures, vestigial structures, and molecular and biogeographic evidence. Important points are that natural selection acts on heritable traits at the population level over many generations, not by design to create perfect adaptations. The theory of evolution, including natural selection, is important in science as it is well-supported by evidence and allows for new predictions and explanations of observations.
Natural selection - an introduction
- 1. 3-13-17 warm up What candy did you pick? Why? Why didn’t you pick the other types?
- 2. There were…now there are 20 snickers 4 milky ways 4 Three Musketeers 66 candy corns 17 fruit chews 5 mints
- 3. Candy • What are the traits of the candy you selected? • What are the traits of the candies you didn’t select? • What if a candy looked good, but inside it was raw onion? • So, the fact that there were different candies with different traits resulted in some candies being eaten and others surviving. • This is what natural selection does with individuals in a population. • Each individual has unique traits; some traits will help an individual survive and some traits do not. • Natural selection only acts on the phenotype, not the genotype.
- 4. Plans for the week Monday 3-13-17: Natural Selection Lesson Tuesday 3-14-17: Practice with lab equipment; n.s. lesson Wednesday 3-15-17: Genetic Transformation Lab Thursday 3-16-17: Genetic Transformation Lab & Report Friday 3-17-17: LAST DAY FOR LATE WORK; Gene Pool mini-lab
- 5. Evolut ion & Nat ural Select ion
- 6. Answer Q1 and Q2 now Essential Questions My initial answer My best answer What is biological evolution? What is natural selection? What are some observations from nature that can be explained by natural selection? Essential Questions My initial answer My best answer What is biological evolution? What is natural selection? What are some observations from nature that can be explained by natural selection?
- 7. Evolution Change over time in the genetic makeup of a population
- 8. Nat ural Select ion One way evolution can happen is through natural selection
- 10. Art if icial Select ion The selection & breeding of individuals that have desired traits Crop plants Livestock Pets Do not resemble their wild ancestors anymore
- 12. Natural selection – is similar to artificial selection except nature, or the environment, “selects” who will survive and mate
- 13. 1 - not all organisms survive 2 - resources are limited Observat ions f rom Nat ure
- 14. 3 – There is variation among organisms 4 - variations are inherited from parents
- 15. Conclusion Individuals with favorable traits survive, reproduce, and pass those traits on to the next generation This is natural selection
- 16. Answer Q1 and Q2 now Essential Questions My initial answer My best answer What is biological evolution? What is natural selection? What are some observations from nature that can be explained by natural selection? Essential Questions My initial answer My best answer What is biological evolution? What is natural selection? What are some observations from nature that can be explained by natural selection?
- 17. Misconcept ions 1. Survival of the fittest = survival of the strongest 2. Evolution is not a “grand plan” that will lead to perfectly adapted species
- 18. 3 import ant point s 1. Individuals are selected, POPULATIONS evolve 2. Natural selection acts only on heritable traits 3. natural selection is always at work PopulationPopulation – a group of interbreeding individuals who live in a particular place at a particular time
- 19. Answer Q3 now Essential Questions My initial answer My best answer What is biological evolution? What is natural selection? What are some observations from nature that can be explained by natural selection? Essential Questions My initial answer My best answer What is biological evolution? What is natural selection? What are some observations from nature that can be explained by natural selection?
- 20. Nat ural Select ion helps explain many observat ions 1. Homology - similar traits resulting from a common ancestor Homologous structuresHomologous structures
- 21. 2. Embryos - all vert. embryos have tail and throat pouches - they develop into different structures in different species
- 22. 3. Vestigial Structures - structures of little to no importance to the organism; the remnants of the organism’s ancestors Femur, pelvis bones
- 24. 5. Biogeography - The geographic distribution of species Closely related species usually found in same geographic region
- 25. The I mport ance of t he Theory of Evolut ion In science, there is no such thing as “just a theory” The theory of evolution is a good theory because: explains tons observations and data can be tested It is broad and allows scientists to make new predictions
- 26. Answer Q3 now Essential Questions My initial answer My best answer What is biological evolution? What is natural selection? What are some observations from nature that can be explained by natural selection? Essential Questions My initial answer My best answer What is biological evolution? What is natural selection? What are some observations from nature that can be explained by natural selection?
- 27. Choose 1 comic and explain how it demonstrates the process of natural selection