Charles Darwin - Anoka-Hennepin School District 11 · 2014. 4. 4. · Darwin’s Evidence Populaon...
Transcript of Charles Darwin - Anoka-Hennepin School District 11 · 2014. 4. 4. · Darwin’s Evidence Populaon...
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Basic Evolu1on
Charles Darwin
Served as naturalist on mapping expedi1on around coastal South America.
Used many observa1ons to develop his ideas
Proposed that evolu1on occurs by
natural selec+on
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Voyage of the Beagle
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Charles Darwin
evolu+on: modifica1on of a species over genera1ons
‐“descent with modifica1on”
natural selec+on: individuals with superior physical or behavioral characteris1cs are more likely to survive and reproduce than those without such characteris1cs
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Darwin’s Evidence
Similarity of related species ‐ Darwin no1ced varia1ons in related species living in different loca1ons
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Darwin’s Evidence
Popula1on growth vs. availability of resources
‐popula1on growth
is geometric
‐increase in food
supply is arithme1c
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Darwin’s Evidence
Popula1on growth vs. availability of resources
‐ Darwin realized that not all members of a
popula1on survive and reproduce.
‐Darwin based these ideas on the wri1ngs of Thomas Malthus.
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Post‐Darwin Evolu1on Evidence
Fossil record ‐ New fossils are found all the 1me
‐ Earth is older than previously believed
Mechanisms of heredity
‐ Early cri1cism of Darwin’s ideas were resolved by Mendel’s theories for gene1c inheritance.
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Post‐Darwin Evolu1on Evidence
Compara1ve anatomy ‐ Homologous structures have same evolu1onary origin, but different structure and func1on.
‐ Analogous structures have similar structure and func1on, but different evolu1onary origin.
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Homologous Structures
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Post‐Darwin Evolu1on Evidence
Molecular Evidence
‐ Our increased understanding of DNA and protein structures has led to the development of more accurate phylogene+c trees.
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