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HISTORY OF EVOLUTIONARY THOUGHT. From Paganism to Darwin and Beyond. http://www.pbs.org/wgbh/evolution/educators/lessons/lesson6/act1notes.html. WHAT IS EVOLUTION?. The change of species over a period of time. WHAT IS YOUR OPINION?.
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HISTORY OF EVOLUTIONARY THOUGHT From Paganism to Darwin and Beyond http://www.pbs.org/wgbh/evolution/educators/lessons/lesson6/act1notes.html
WHAT IS EVOLUTION? • The change of species over a period of time
WHAT IS YOUR OPINION? Please write down the answers to the following questions in your notes. • Cheetahs can run faster than 60 miles/hour when chasing prey. How would a biologist explain how this ability evolved in cheetahs assuming their ancestors on average ran 20 miles/hr? • Cave salamanders are blind (their eyes are non-functional). How could a biologist explain how this inability evolved from sighted ancestors?
PRE-DARWIN IDEAS • Earth is young • Earth is not changing
HISTORY: In the beginning… Plato and Aristotle (mid 300 B.C.) • Scale of Nature
EVIDENCE FROM GEOLOGY James Hutton • He proposed the theory of uniformitarianism • Earth was formed entirely by slow-moving processes, such as erosion and sedimentation, and that these slow forces continue to shape the landscape. Charles Lyell • 1830 wrote Principles of Geology that Darwin read on his journey supporting Hutton’s work
JUDEO CHRISTIAN CULTURE Exploring God’s work • Carlos Linnaeus (1700s): Taxonomy • George Cuvier (late 1700s): - Paleontology: Found that fossils were dissimilar to modern life - Species can become extinct - Species can change over time
Erasmus Darwin • Grandpa! • Termed evolution • Life developed from a single sources • Humans close to primates (how dare he!)
O.K. SPECIES EVOLVE BUT WHAT MAKES THEM EVOLVE? MECHANISMS BEHIND EVOLUTION Jean Baptiste Pierre Antoine de Monet, Chevealier de Lamarck…a.k.a. Lamarck! • Published in 1809 when baby Darwin was born • Looked at fossil record and role of environment • Idea #1: use and disuse • Idea #2: inheritance of acquired characteristics
Charles Darwin (1809-1882) • Beagle voyage around the world • Looked at living organisms and fossil record
PATTERNS IN DIVERSITY 1. Species vary Globally Rheas in South America Emu in Australia Ostrich in Africa
Darwin questioned why are marsupials only found in Australia even though Europe had a similar environment.
Unique South American Character • A South American tropical lizard more similar to a S.A. desert lizard than another lizard elsewhere
2. Species Vary Locally • What does the difference in structure between the two tortoises tell you about the island they occupy? Galapagos Tortoises
3. Species vary over time • Ancestor of armadillo was much bigger
Darwin also observed on his journey the geological process Hutton and Lyell also observed • He witnessed earthquakes, changing landscapes • He found marine fossils high up in the mountains of the Andes in Chile
Working towards a theory of Natural Selection • Malthus’ work: population size can increases exponentially but it remains stable over time…why?
3 Points To Darwin’s Theory • 1. There is a struggle for existence
2. Role of the Environment: Natural Selection • There is variation in a population
The environment plays a role in • keeping populations in check • Natural selection is the process of selecting for a variation that is best suited to its environment • “Survival of The Fittest”: those that can survive and reproduce the most viable offspring are the most fit
Alfred Wallace (1823-1913) • I have this theory about natural selection charlsey boy, what do you think? Darwin’s Origin of Species • Decent with modification (evolution) • Natural Selection • Decent of Man was also then published
Did your ideas reflect Darwin or Lamarck’s • What does modern day genetics support? Evolution of Hummingbirds http://www.youtube.com/watch?v=uHyjGQJCAMU • http://www.pbs.org/wgbh/evolution/library/11/2/e_s_4.html