Transcript S7L5.b
No RP today. Have your pencil ready and be in your seat when the bell rings. Today in Science ! ! ! Begin Evolution Standards please S7L5 Students will examine the evolution of living organisms through inherited characteristics that promote survival of organisms and the survival of successive generations of their offspring. S7L5.a Explain how physical characteristics of organisms have changed over successive generations (e.g. Darwin’s finches and the peppered moths of Manchester). S7L5.b Describe ways in which species on earth have evolved due to natural selection. S7L5.c Explain how the fossil record found in sedimentary rock provides evidence for the long history of changing life forms. Meet Darwin New T o C Late grades: Disease Foldable Notebooks due tomorrow ! Evidence for Evolution 1. In 1831 Charles Darwin traveled around the world. In the Galapagos Islands he observed a great variety of organisms like finches p.175, tortoises and iguanas. Who was Charles Darwin? • Darwin had begun to think that species could evolve over time. It became clear to Darwin that Earth was much older than anyone had imagined. • What Is a Species? A species is a group of organisms that can mate with one another to produce fertile offspring. A characteristic that helps an organism survive and reproduce in its environment is called an adaptation. 3rd stopped here 2. The evidence Darwin collected led him to theorize that living things change over time or evolve. 3. Current evidence for evolution: (6) and (5) A. Fossil record. Oldest fossils buried deeper. Horses evolved from a dog sized animal 60 mya B. Phylogeny – the evolutionary history tells which species evolved from other species or had common ancestors. 2nd stopped here 4. How do we know the phylogeny – the history of how different organisms evolved? Phylogeny is determined . . . a. b. c. d. Similar body structures p. 172 G 168` Similar embryonic development Glencoe 169 Similar DNA codes Vestigial structures a. Similar Body Structures b. Embryonic Development Because so many species are so similar in their development, it may suggest a common ancestor. c. Similar DNA d. Vestigial structures Some species have structures that they do not need. For example, humans ~ appendix whales ~ tiny hip bones that whales do not need may have been inherited from their walking ancestors. 1st stopped here • AB partners 5. What is Natural Selection? Evolution occurs because of Natural Selection – organism that is better adapted lives longer and produces more offspring. RP:This is another cladogram. What do these type of diagrams show us? Natural Selection • Big Five Facts ~ 1. Overproduction: This refers to the way many species produce waaaay more offspring than can possibly survive. Video clip 12:45 What type of reproduction? What is that called when the baby looks so different from the mom? Process of change? 2. Variation (differences) exist among individuals in a species 3. Competition ~ individuals of a species compete for resources. 4. Selection : Individuals with advantageous variations are more likely to survive. And those individuals that survive reproduce and pass on those advantages through their genes. When that organism dies the less advantageous genes die with it The variations can be a result of heredity or mutations • 3 Vocabulary words (new) • 2 questions you still have • 1 really good, complex or compound summary sentence of what we have learned from these notes. Venn Diagram • Video clip 15 min natural selection • Compare natural selection to selective breeding (aka artificial selection) Evidence of Species that have evolved • Bacteria • Moths • Finches