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An Introduction to. Evolution. What do you want to know?. Write down what you know about evolution Write down what you want to know about evolution. How did life begin?. Theory A. “Primordial Soup” model
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An Introduction to Evolution
What do you want to know? • Write down what you know about evolution • Write down what you want to know about evolution
How did life begin? • Theory A. “Primordial Soup” model • This theory states that the first life on earth appeared in a "primordial soup" consisting of water loaded with chemicals necessary for the start of life. This "warm little pond" was believed to have been struck by an electrical discharge (most likely from lightning) which caused the chemicals to form complex protein molecules, which eventually evolved into other life forms. • Simulated by Miller & Urey
How did life begin? • Theory B. “Bubble” Model: • Gases from undersea volcanoes rose to surface of oceans and reacted with UV radiation and lightning producing existing gases • (Proposed by Louis Lerman)
III. From chemicals to us! • Over the course of a billion years, simple organic molecules changed and created primitive (simple) cells • Very slowly, these cells became more complex and genetically changed into different species • A brief review of history…
IV. Who discovered Evolution? JEAN-BAPTISTE LAMARCK Came up with the theory that parents could pass on acquired characteristics. Acquired characteristics are things that happen to you during your lifetime, they are not inherited.
IV. Who discovered Evolution? This theory is no longer accepted it has been disproved by an experiment where mice had their tails cut off (aquired characteristic). Would that be passed on to offspring? Why? Why not?
IV. Who discovered Evolution? JEAN-BAPTISTE LAMARCK He also founded the principle of use and disuse: If an organ is used, it will become stronger, and if it is not used, it will weaken and may disappear in future generations.
Who discovered evolution? CHARLES DARWIN A scientist that traveled the seas observing nature. His theories are more widely accepted than Lamarck’s Came up with “Natural Selection” while observing the finches of the Galapagos Islands. Natural Selection also known as survival of the fittest.