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Information obtained from: Holt Science and Technology: Life Science. Austin: Holt Rinehart & Winston, 2007. Print.
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Chapter 7 Section 2
List 4 sources of Charles Darwin’s ideas about evolution.
Describe the 4 parts of Darwin’s theory of evolution by natural selection.
Relate genetics to evolution.
He was interested in the study of plants and animals
1831 - He signed on as a naturalist for a 5 year voyage around the world on the British ship the HMS Beagle
He made observations the helped form his theory of evolution
http://biblauragraphy.files.wordpress.com/2009/02/darwin.jpg
1000’s of plant and animal samples were taken
Observations were recorded Most notable stop: The Galápagos
Islands (965km west of Ecuador in South America)
http://farm1.static.flickr.com/21/97887748_cba82d3784.jpg
http://upload.wikimedia.org/wikipedia/commons/4/42/Voyage_of_the_Beagle.jpg
The Galápagos Island plants and animals were very similar to those in Ecuador
Ex: Finches of Galápagos were similar, but different; each island also showed differences in the finches
Their beaks were adapted to the way the bird gets their food
http://biology.unm.edu/ccouncil/Biology_203/Images/PopGen/darwin_finches.jpg
Darwin hypothesized that the island finches were descended from South American finches
Over many generations the finches evolved adaptations for the various island environments
http://www.blackwellpublishing.com/ridley/images/finch_magnirostris.jpg
Vocabulary: Trait: a characteristic that can be passed
from parent to offspring through genes
Selective Breeding: the human practice of breeding animals or plants that have certain desired traits
Ex: pets (dogs) are bred for desired traits
Thomas Malthus: An Essay on the Principle of Population
Malthus thought that the human population could increase more quickly than the food supply
Darwin: populations of all species are limited by starvation, disease, competition, and predation
Only a limited number of individuals survive to reproduce; offspring of the survivors inherit traits that help them survive in their environment
Most geologists in Darwin’s time did not think the Earth was old enough to allow for these slow changes
Charles Lyell: Principles of Geology
The Earth has formed by natural processes over a long period of time; the Earth was pretty old!
1858 – Alfred Russel Wallace arrived at the same ideas as Darwin
1859 – Darwin published Origin of Species by Means of Natural Selection
Natural selection: the process by which organisms that are better adapted to their environment survive and reproduce more successfully that less adapted organisms do
1. Overproduction
2. Inherited variation
3. Struggle to survive
4. Successful reproduction
http://evolution.berkeley.edu/evolibrary/images/interviews/naturalselection1.gif
Darwin lacked some evidence for parts of his theory
He did not know HOW organisms inherited traits
Differences in genes
What did Darwin learn from Lyell’s data about the age of the Earth?
Give an example of selective breeding.