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Click HERE for your print-friendly copy of the notes. Don't print the big font pages! "Nothing in biology makes sense except in the light of evolution." -- Theodosius Dobzhansky , Geneticist A Poll: Which is the most highly evolved species? EVOLUTION is defined as change over time. ORGANIC EVOLUTION is the genetic (and phenotypic) change of living organisms over time. The universe is thought to be about 10-20 billions years old. k Our solar system, along with earth - 4.5 billions years old Life on earth first appeared approximately 4 billion years ago , with proto-humans (genus Homo ) first appearing in the fossil record of the Pleistocene (about 1.8 million years ago) and humans (species Homo sapiens first showing up about 500,000 - 300,000 years ago. Modern humans (species Homo sapiens sapiens showed up around 150,000 years ago.) Before humans were even aware that we had been around that long, they were already trying to figure out where we had come from, and they had all sorts of creative ideas about the origins of life. 7 As long ago as 500 B.C, Greek philosophers were already toying with the idea that life was constantly changing. However, the most influential of these, PLATO and his student, ARISTOTLE , believed in an unchanging world in which all species had been created in a perfect state, with perfect
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interactions intact. In such a world, evolution would be counterproductive, and against the plan of The Creator. " The Old Testament account of The Creation fortified this idea, and even as recently as the 1700's, biology was done in a framework of natural theology--the idea that science should be dedicated to studying nature in order to figure out the Grand Plan of the Creator. " The early idea that living organisms could "spring" from non-living material, fully formed, is termed SPONTANEOUS GENERATION. (e.g., maggots from rotting meat; lice from sweat; eels from sea mud, etc. .) In 1668, FRANCESCO REDI , an Italian physician performed experiments designed to test this idea. ; He placed rotting meat in covered and uncovered jars, and noted that maggots formed only in the uncovered jar. ("Hey! Maggots must be fly larvae!") 1 In 1676, Dutch scientist ANTON VAN LEEUWENHOEK invents the microscope, revealing a microscopic world of wigglies. Once again, interest in spontaneous generation was revived (though on a "smaller scale") In the late 1700's - LAZARO SPALLANZANI performed an experiment designed to test the spontaneous generation of microorganisms. (He boiled broth in flasks, and left one covered,one uncovered; only the uncovered one produced microorganisms.) However, his experiments were discounted because. .. 1. others with less meticulous techniques got bad results (both vessels were contaminated, and both grew microorganisms)
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2. critics said that boiling the broth might have somehow destroyed some "vital principle" in the broth and/or air, making it unfit for spontaneous generation. In 1862,
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This note was uploaded on 04/08/2008 for the course BIL 160 taught by Professor Krempels during the Spring '08 term at University of Miami.

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