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E VOLUTION CHANGES OVER TIME Life Science 7 th grade Mrs.Akers

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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. S7L5a Explain that physical characteristics of organisms have changed over successive generations (e.g. Darwins finches and peppered moths of Manchester). S7L5b Describe ways in which species on earth have evolved due to natural selection. S7L5c Trace evidence that the fossil record found in sedimentary rock provides evidence for the long history of changing life forms. U NIT 6 E VOLUTION (S TANDARDS )

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TOPIC : Evolution KEY LEARNING : Through natural selection, organisms evolve and adapt to survive and fossils provide evidence of an organisms presence on Earth. UNIT ESSENTIAL QUESTION : What type of evidence supports life existed and changed before our time? U NIT 6 - E VOLUTION : S TUDENT L EARNING M AP

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CONCEPT 1 : Fossils and Pangaea Lesson Essential Questions : 1. How are fossils formed? 2. How is the age of fossils determined? 3. How do fossils support the theory of Pangaea? Vocabulary : evolution, gradualism, punctuated equilibrium, Pangaea, continental drift, fossil, relative dating, radiometric dating U NIT 6 - E VOLUTION : SLM

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T HEORY VERSUS F ACT Fact A scientific observation known to be true. Theory A broad concept, thought to be true because it explains many facts.

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E VOLUTION Evolution Change over time Involves genetics Includes adaptations-a trait that helps an organism survive and reproduce.

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F IVE TYPES OF FOSSILS S7L5 C Imprint- Sediment fills an organisms track Mineralized- Minerals seep into pores of wood or bone, dissolve the organic matter, then crystallize retaining its cell structure shape. Frozen- organism trapped in mud, tar, then temperature drops fast & organism freezes instantly! (rare) Ex: Ice Age Fossils in amber- sticky resin of certain cone- bearing plants/trees traps insects/organisms. DNA can be extracted. Ex: Jurassic Park Cast- organism decomposes and leaves a cavity (space) that fills with sediment or minerals.

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S OLID F ORMS OF P LANTS AND A NIMAL F OSSILS S7L5 C (M ADE FROM SEDIMENT : MUD, SAND, OR VOLCANIC ASH )

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F OSSIL R ECORD : D ETERMINING A FOSSIL S AGE S7L5 C Absolute Dating VS. Estimating the age of SEDIMENTARY rocks or fossils by comparing the amount of radioactivity elements to others. *Can be inaccurate Relative Dating In an undisturbed area, where younger rock layers are deposited on top of older rock layers. *Earthquake or plate movement can disrupt accuracy.

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F OSSIL R ECORD : A GE OF F OSSILS (S7L5 C )

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G EOLOGIC TIMELINE D ATING THE A GE OF F OSSILS (S7L5 C )

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T HEORY OF C ONTINENTAL D RIFT PANGEA Earth formed 4.6 BYA (Billion Years Ago) 1915, Alfred Wegener studied similar plant and animal fossils found on different present-day continents. He theorized continents once formed one giant supercontinent called Pangaea. Then, 245 MYA, Continental drift -Movement of Earths continents took place due to tectonic plates shifting. http://vimeo.com/14258924 http://www.tectonics.caltech.edu/outreach/animations/drift.html

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(S7L5a,b) Speed of Evolution: When the continents drifted, this led to changes . Gradualism- A slow, ongoing process by which one species changes to a new species versus Punctuation equilibrium- Rapid evolution that comes about when the mutation of a few genes results in sudden change (appearance) of a new species

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CONCEPT 2 : Charles Darwin and Natural Selection Lesson Essential Questions : 1. What is Darwins role in the theory of evolution? 2. What are the different speeds of evolution? 3. What are the four parts of Darwins theory of evolution by natural selection? Vocabulary : fossil, finches, peppered moths,camouflage, variation, overproduction, natural selection, competition, adaptation. U NIT 6 SLM: S7L5 A N ATURAL SELECTION, S7L5 B - CHANGE IN PHYSICAL CHARACTERISTICS

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C HARLES D ARWIN : V OYAGE ON HMS B EAGLE 1831-left England Sept. 15,1835 -Visited Galapagos Islands off coast of South America 1836 Returned England

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www.carlwozniak.com

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C HARLES DARWIN (S7L5 A, B ) Studied plants and animals as a naturalist on HMS Beagle - British ship. Observed and hypothesized finch species that were geographically isolated from each other. Darwin reasoned that finch populations over time evolved adaptations that aided in their survival on different island environments resulting in new species. Adaptation- a trait (genetic characteristic) that improves an organisms ability to survive and reproduce in a certain environment Examples: (beak, fur, camouflage) Speciation- new species occurs from 3 events: Separation, Adaptation, and Division

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D ARWIN S F INCH S ON G ALAPAGOS I SLANDS AND S OUTH A MERICA B EAKS DIFFER T YPES OF FOOD EATEN ( SMALL LARGE )

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D ARWIN S F INCH S (S7L5 A ) V ESTIGIAL STRUCTURES - E XAMPLE : BEAKS Probing bit-insect eater- feeds in trees. (4) Probing bit-insect eater that uses a twig or cactus spine to probe insects. (3) Grasping bit-insect eater that feeds in trees. (2) Crushing bit-cactus seed eater. (1)

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D ARWIN S F INCH S (S7L5 A ) "Calmodulin is a protein that binds and activates certain enzymes, which triggers a signal that eventually turns specific genes on or off," explains Arkhat Abzhanov, an evolutionary biologist at Harvard. The signals alter the behavior of cells responsible for beak sculpturing.

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D ARWIN S F INCH S (S7L5 A ) As climate changes in the Galapagos the finchs changed body size, beak size, and beak shape (a measure of width, length and depth). In 1983, after heavy rains, depth of average finch beak returned to pre-drought size, and "evolutionary change" reversed. Explore Evolution, p. 93

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N ATURAL SELECTION (S7L5 B ) A Process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species. Involves genetics; not environment Occurs over many generations (cant see it happening) Other terminology Survival of the fittest Only the strong survive

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N ATURAL SELECTION (S7L5 B ) Overproduction Too many offspring; not enough resources (food, water, living space) usually die. Competition For resources food or mates; competing against other offspring Variations Differences between individuals of same species Selective When the environment selects organisms with helpful traits

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QUIZ BELOW http://www.sciencechannel.com/games-and- interactives/charles-darwin-game.html

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D ARWIN - T REE OF L IFE organized beings represent a tree, irregularly branched, some branches far more branched Hence Genera. (ABCD-Different species branch off from 1).

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CLADOGRAM (T REE OF L IFE ) : (S7L5 A, B, C ) Cladogram: A diagram or model of relationships between extinct and living species. Each branch in the diagram represents a group of organisms that descended from that species. http://evolution.berkeley.edu/evosite/evo101/IIHis tory.shtml PBS video Clips: Whale Evolution and Fish w/ Fingers Evolution Clip Videos http://www.pbs.org/wgbh/evolution/educators/teac hstuds/unit3.html

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P RESENT T IME

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C HARLES DARWIN FOLDABLE / BROCHURE / NEWSLETTER Must include the following items: Cover page (name, date, class period, title) Mini bio on Charles Darwin Philosophy of evolution What did Darwin contribute to science? Describe what he learned about the finches. Describe what he learned about peppered moths. Each page/section should include a picture Final page/section should have resource(s) listed (MLA style) DUE: TUESDAY, APRIL 2

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R ESOURCES http://ncse.com/creationism/analysis/oscillations http://www.news.harvard.edu/gazette/2006/08.24/3 1-finches.html