4-9-18 Theory of Evolution by Natural Selection

Do Now: In your Science Notebook: Create a KWL chart on what you know about the theory of evolution.

Myths and misconceptions about evolution https://youtu.be/mZt1Gn0R22Q?t=10s

Quiz Review: Energy in Ecosystems - Cambridge Food web 6. 0.2 points for each correctly drawn arrow Producers Consumers Energy pyramid Food chain

Quiz Review: Energy in Ecosystems - Cambridge 7. B, C, D (Primary, Secondary, & Tertiary Consumer) Primary: Grass  Mouse Secondary: Grass  Grasshopper  Mouse Tertiary: Grass  Grasshopper  Spider  Mouse +0.5 points if circled 2 correct answers +0 points if circled A and/or only 1 correct answer 8. Hawk population 9. Grasshopper population

Quiz Review: Energy in Ecosystems - Comprehensive B. herbivore B. detritivore D. food web A. producer B. consumer E. energy pyramid C. food chain See figure to right (2 points) 0.33 points for each correctly drawn arrow

Quiz Review: Energy in Ecosystems - Comprehensive 9. B & C (largemouth bass & northern pike; humans) +0.5 points for each correct answer circled -0.5 points for each incorrect answer circled

Quiz Retake Requirements Complete the Ch. 14, Lesson 3 Outline using your notes AND online textbook. Study. Check with Mr. Santos for availability to retake quiz in the mornings. Come in at 8:30am with completed assignment to retake the quiz.

Ch. 13, Lesson 2: Theory of Evolution by Natural Selection Standards: SC.7.L.15.2, SC.7.L.15.3 Lesson Objective: Students will be able to recognize and explain ways in which genetic variation and environmental factors contribute to evolution

Theory of Evolution by Natural Selection Essential Questions Who was Charles Darwin? How does Darwin’s theory of evolution by natural selection explain how species change over time? How are adaptations evidence of natural selection?

Vocabulary naturalist variation natural selection adaptation camouflage mimicry selective breeding

EQ: Who was Charles Darwin EQ: Who was Charles Darwin? EQ: How does Darwin’s theory of evolution by natural selection explain how species change over time?

Theory of Evolution by Natural Selection How many species of birds can you name? Robins, chickens, turkeys, ostriches, sea gulls, etc. Scientists estimate there are about 10,000 species of birds today Each bird species has similar characteristics (wings, feathers, beak) Scientists hypothesize that all birds evolved from an earlier population of birdlike organisms. As this population evolved, birds became different sizes, colors, etc. How do birds and other species evolve?

Charles Darwin Charles Darwin was an English naturalist who, in the mid-1800s, developed a theory of how evolution works. Naturalist: a person who studies plants and animals by observing them. Naturalista: persona que estudia las plantas y los animals por medio de la observacion Darwin spent many years observing plants and animals in their natural habitats before developing his theory. Remember, a theory is an explanation of how something occurs that is well supported by evidence.

Darwin’s Theory Darwin found that each island in the Galápagos had a different environment, and tortoises looked different depending on which island environment they inhabited. Darwin became convinced that all the tortoise species were related and shared a common ancestor. As the ancestral population spread to the islands, the tortoises changed to match their islands’ food sources.

Darwin’s Theory Variation: a slight difference in an inherited trait among individual members of a species. Variacion: ligera diferencia en un rasgo hereditario entre los miembros individuales de una especie. Variations arise naturally in populations due to random mutations occurring in offspring as a result of sexual reproduction. Genetic changes to phenotype can be passed on to future generations.

Natural Selection Natural selection the process by which populations of organisms with variations that help them survive in their environments live longer, compete better, and reproduce more than those that do not have the variations. Seleccion natural: proceso por el cual los organismos con variaciones que las ayudan a sobrevivir en sus medioambientes viven mas, compiten major y se reproducen mas que aquellas que no tienen esas variaciones.

Natural Selection: Copy this flow chart Darwin understood that food is a limiting resource. Tortoises had to compete with each other for food. Some tortoises were born with random variations in neck length. If a variation benefited a tortoise, allowing it to compete for food better than other tortoises, the tortoise lived longer. Because it lived longer, it reproduced more. It passed on its variations to its offspring. This is Darwin’s theory of evolution by natural selection. Natural selection explains how populations change as their environments change. Natural Selection: Copy this flow chart Reproduction Variation Selection – some variations are more beneficial Increased likelihood to survive and reproduce Pass on variations to offspring (more variation = more diversity)

Turn & Talk What role do variations have in the theory of evolution by natural selection? If a variation helps an organism survive in its environment, it increases in the population through natural selection.

Closure Update your KWL chart

Homework: Key Concept Builder: How does Darwin’s theory of evolution explain how organisms change over time? Use your textbook, Ch. 13 Lesson 2, to complete the worksheet.