development of a theory development of a theory mechanisms of selection mechanisms of selection...
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Evolution
Development of a Theory
Mechanisms of Selection
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Development of a Theory
A. Evolution
B. Voyage of Charles Darwin
C. The Origin of Species
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A. Evolution
1. Evolution is a change in the hereditary features of a population over time
a. adaptations are traits that make organisms better able to survive
b. mutations are the source for new traits_
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IN YOUR OWN WORDS, DESCRIBE THE PROCESS OF EVOLUTION.
Think about it!
Think
2. Earlier ideas proposed inheritance of acquired characteristics
a. giraffe necks lengthen by stretching over time
b. mistaken explanation_
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B. Voyage of Charles Darwin
1. Charles Darwin voyaged around the world on the HMS Beagle
a. gathered plant and animal specimens
b. made observations on the Galapagos Islands
c. read about gradual geological processes that shape the Earth
2. Wrote On the Origin of Species which explained his theory of natural selection_
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C. The Origin of Species
1. Descent with modification
a. organisms living today descended from ancestors
b. they accumulated modifications to diverse ways of life_
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2. Natural selection
a. if the environment changes
b. different genes may become more advantageous
c. leading to a change in the characteristics of a population of organisms
3. The “peppered moth” of Manchester England_
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Mechanisms of Selection
A. Natural Selection
B. Artificial Selection
C. Selection in Action
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1. Overproduction- more organisms are produced than can survive
2. Variations- caused by genes can be passed on to offspring_
A. Natural Selection
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WHAT DO YOU THINK OF WHEN YOU HEAR THE TERM, “SURVIVAL OF THE FITTEST” AND HOW DO YOU THINK IT WOULD APPLY TO HUMANS IN OUR SOCIETY?
Think about it!
Think
3. “Struggle for existence”- some variations give advantages over others
4. “Survival of the fittest”- genes conferring advantageous adaptations are more likely to be passed on
5. Speciation- evolution of a new species with adaptations_
National Geogrraphichttp://animals.nationalgeographic.com/animals/wallpaper/galapagos-tortoise_image.htmlaccessed 17.09.09
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B. Artificial Selection
1. Artificial selection- humans determine if an organism will survive to have offspring
a. domesticated plants
b. domesticated animals_
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2. Selective breeding of berries
a. natural variation exists in a field of berries
b. humans pick the large sweet berries
c. seeds are planted from the chosen berries
d. several generations pass_
GardenWisehttp://www.gardenwiseonline.ca/gw/ask-pros/2008/11/28/how-replant-mature-blueberry-bushesaccessed 12.09.09
1. Sickle cell anemia affects 4% in parts of Africa
a. two alleles- suffer from disease
b. one allele- resistant to malaria (32% of population)
c. no allele- susceptible to malaria_
C. Selection in Action
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2. Overuse of pesticides has lead to resistance in insects through natural selection_
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3. Overuse of antibiotics has lead to resistance in bacteria by natural selection
a. tuberculosis (TB)_
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