Section A2.4 Notes - Section A2.4 Notes August 31 September...

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Section A2.4 Notes August 31 – September 4 Chapter 22 Descent with Modification Overview 3 Important Observations on Life: o Organisms fit environment in which they live o Characteristics of life are shared o Life is varied Charles Darwin’s goal was to explain these 3 observations o The Origin of Species o Evolutionary biology Evolution = a pattern and a process o Pattern – supported by data (facts) from observations about world o Process – mechanisms (natural causes of natural phenomena) that construct pattern Concept: Darwinian revolution challenged traditional views of young Earth inhabited by unchanging species Earlier Ideas on Species: o Aristotle believed species were unchanging Scala naturae – Aristotle’s idea that life-forms could be set on a scale of increasing complexity Each form of life had permanent spot on scale o Carolus Linnaeus developed binomial system for naming species Grouped similar species in same genus, and so on Differences, to Linnaeus, were due to the pattern of their creation (sought to classify life for God’s glory) Darwin drew roots from studies of fossils
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o Paleontology – developed by Georges Cuvier Inferred extinctions must have often occurred in history by studying changes in species in different layers of strata Didn’t believe in evolution, rather catastrophism Events in past caused suddenly and by devices not found in present Each layer of strata separated by catastrophe o James Hutton – Earth’s features could be explained by slow mechanisms that were still going on o Charles Lyell – Uniformitarianism Mechanisms of change are unvarying over time Jean-Baptiste de Lamarck o Had idea of evolution but wrong mechanism Two principles: Use and Disuse – Parts of body used most often become stronger and larger; parts not used often weaken Inheritance of Acquired Characteristics – Organisms can pass off modifications (from use and disuse principle) to offspring o Evolution occurs because organisms have a natural drive to become more complex Concept: Descent with modification by natural selection explains adaptations of organism and unity and diversity of life Darwin’s Research: o Quit medical school to become a clergyman (what many scientific scholars were) Through connections of a professor, Darwin became conversation partner to the caption of a survey ship, HMS Beagle (1831) Surveyed coast of South America Darwin collected South American organisms o Saw that attributes of organisms suited environment o Saw that organisms of South America more closely resembled each other than organisms from similar environments in Europe
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Famous Galapagos study – hypothesized that organisms from South America colonized the islands then diversified into new species o Focused on adaptations Adaptation to environment and origins of new species are closely related Explanation was centered around natural selection
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This note was uploaded on 01/25/2011 for the course BIO 1510 taught by Professor Unknown during the Spring '07 term at Georgia Institute of Technology.

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Section A2.4 Notes - Section A2.4 Notes August 31 September...

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