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Bellringer #2 In your composition books, write the questions and answers! True or false, 2 species can mate and create a brand new species. True or false a caterpillar growing into a butterfly is evolution? Define evolution
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Bellringer #1 In your composition books write the questions and answers What is evolution? (educated guess) How does evolution happen (educated guess) Where have you heard the word evolving (educated guess)
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The Theory of Evolution
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#1 What is a Theory? A theory is the best explanation based on the evidence available. There is a great deal of evidence to support the theory of evolution.
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What is evolution? Definition: Result:
The process of change in a species over time Result: A species changes so much over time that the species is no longer the same as its original ancestor and would not be able to mate with the original ancestor.
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What is the evidence that supports the theory of evolution?
#2 What is the evidence that supports the theory of evolution? Similar species (like the finches) Fossils (very different organisms were alive millions of years ago) Similar DNA (humans & chimps have 99.9% same DNA) Analogous structures (similar bones in a hand, fin, and wing)
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Species? What is a species? A species is a group of organisms that can mate and produce fertile offspring! #3
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What does fertile mean? Definition: Can have offspring
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How can one species become 2? (Evolution in Bacteria)
living on a rotting log living under a rock How can one species become 2? (Evolution in Bacteria) Separate Species
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Common Ancestors A common ancestor is a previous species that new species evolve from. Evolutionary theory suggests that monkeys and humans have a common ancestor. Misconception: Humans evolved from monkeys. THIS IS NOT TRUE! WHAT IS TRUE? Humans and monkeys (and apes) have a common ancestor.
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Common Ancestor: 6 million years ago Evolutionary Tree
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Why do scientists use a Tree vs. something else?
#4 Why do scientists use a Tree vs. something else? Where the branches meet the trunk shows a common ancestor!
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What are some examples of organisms with a common ancestor?
#5 What are some examples of organisms with a common ancestor? Monkeys and humans Land plants and seaweed
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Evolution is NOT: #6 Evolution is NOT changes in population size
Evolution is NOT individual organisms growing and going through metamorphosis such as a tadpole changing into a frog Evolution is NOT individual organisms evolving during their life time. THIS IS NOT POSSIBLE! An organism cannot acquire (get) a better trait during its life and then pass it on to its offspring.
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How Does Evolution Happen?
Mutations randomly occur to produce variations. Sexual reproduction also creates variations. Organisms with beneficial variations (adaptations) are better able to survive. Over time, a variety of beneficial mutations accumulates in the species. The accumulation of many changes over time can lead to the production of a new species!
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#7 Put the steps in order! 3 ___Over time, a variety of beneficial mutations accumulates in the species. ___Mutations randomly occur to produce variations. Sexual reproduction also creates variations. ___The accumulation of many changes over time can lead to the production of a new species! ___Organisms with beneficial variations (adaptations) are better able to survive. 1 4 2
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Evolution of the Horse How has the horse changed over time? #8
Different Species #8 How has the horse changed over time? body shape toes to hooves size (bigger)
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Misconceptions on How Evolution Occurs:
NOT TRUE: Organisms get the mutations they need and so they evolve to fit their environment. NOT TRUE: 2 species (such as cat & dog) can mate to create a brand new species.
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How Quickly Does Evolution Happen?
#9 How Quickly Does Evolution Happen? Time for evolution to happen depends on… Reproduction (type, rate, gestation period, number of offspring, etc.) Mutations: (more mutations = faster evolution) (more pollutants can lead to more mutations) Environmental changes (will reduce some variations, increase other variations) Example: bacteria found in a hospital may evolve rapidly (fast reproduction, changing environment due to various medicines, etc.)
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Albert Einstein 9 years
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Summarize… Organism Time Frame Numbers #10 Rate of evolution Bacteria
5 hours 3 million Cats 9 years (78,840 hours) 11 million Humans 1 Rate of evolution Rank order: Cat, Human, Bacteria #10 Bacteria Cat Human Fastest Slowest
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Extinction all members of a species die. occurs when a species does not have the right adaptations to survive in the environment. #11 What is it called when there are NO members of a species alive? Extinction
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Dinosaur Extinction One Theory:
An asteroid hit the Earth and sent up a cloud of dust which blocked sunlight for several years. This caused climate change and killed many plants. Dinosaurs were not well adapted to survive the changes.
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Mrs. Henderson thinks this is the real reason dinosaurs went extinct!
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What species are extinct?
#12 What species are extinct? Dinosaurs Dodo Bird Saber tooth tiger Woolly Mammoth Plus Many Millions More! (90% of all species that ever lived have gone extinct)
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What is an endangered species?
#13 a population of organisms which is at risk of becoming extinct Few in numbers Threatened by changing environment Threatened by predators About 40% of all organisms are endangered, but only a few of the many species at risk of extinction actually make it to the endangered species list.
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Examples of Endangered Species
#14 Panda Eastern Tiger Salamander Cougar
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