The Theory of Evolution The continuing controversy

Important People 1. Jean-Baptiste Lamarck French Naturalist who reasoned that the fossils of extinct animals were the ancestors of those living today Hypothesized that “use and disuse” determined traits that were passed on.

2. Charles Darwin Traveled the world onboard the HMS Beagle. Studied organisms with variations on the Galapagos islands Published the book Origin of Species which explained his theory of evolution.

3. Alfred Wallace Discovered same theory as Darwin, but just after him, so Darwin got the most credit.

Explanations of Evolution A. Gradualism by Natural Selection. I have called this principle, by which each slight variation, if useful, is preserved, by the term Natural Selection.                         —Charles Darwin from "The Origin of Species" New species evolve slowly over time Long time period required (4.5 billion yrs.) - Supported by the age of fossils and the geological record.

Fossils, Geology

Grand Canyon

Natural Selection 1. There is variation within populations. 2. Some variations are favorable 3. Not all young produced in each generation can survive. 4. Individuals that survive and reproduce are those with favorable variations. “Survival of the Fittest” (evolution’s driving force)

Problems with gradualism 1.Young-earth philosophy- Age of DNA, Age of “mitochondrial Eve” 2. Gaps in fossil record “the fossil record lacks the intermediate life-forms Darwin and others expected to see” (Strauss/Lisowski, 237) http://www.genesispark.com/exhibits/fossils/missing-links/gaps/ “The known fossil record fails to document a single example of phyletic evolution (a species becoming a new species) accomplishing a major morphological transition. (Stanley, 39)

Quote (chemistry perspective) Question posed by David Duncan of Discover Magazine, December, 2003: “What about the extraordinarily complex questions, such as the origin of life?” Answer by George Whitesides, Mallinckrodt Professor of Chemistry at Harvard. “This notion of life as a traceable continuum with increasing complexity is something that I think is going to be pretty troubling to work out.” (Duncan, 2003)

Alternative explanation of Evolution B. Punctuated equilibrium- attempts to explain gaps in the fossil record. populations remain stable for long periods of time, then are interrupted by brief periods of rapid genetic change. Founded by Stephen J. Gould

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