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12 Cards in this Set
- Front
- Back
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Homology suggested…
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relationships among species
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Paleontology suggested…
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-Evolution. (saw that species changed) (early 1800’s)
-Fossils found of extinct species & they suggested similarities btw current & past species |
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Darwin-
-"On the Origin of Species by Means of Natural Selection" 4 Main Observations: |
1. Reproduction increases population unless factors limit it.
2. Individuals in a species are not identical. 3. Some variation among individuals is inherited. 4. Not all offspring survive to reproduce. |
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*Darwin’s major inference from his observations:
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-Variations among individuals affect probability of surviving & reproducing --> probability of passing on those characteristics
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Darwin’s major contribution…
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-Natural Selection.
(Processes of evolution) |
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Evolution-
(Includes) Speciation- |
-Change in the properties of a species over generations
-Development of new & separate species. |
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Natural Selection
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-The differential survival &reproduction of organisms w/ heritable characteristics
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Survival of the "fittest"-
(Later called "Sexual Selection") |
-refers to how well a species or member of the species “fits” into its niche.
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(A BEHAVIORIAL &/or PHYSICAL gene mutation may be selected if it’s adaptive.
-Physical traits & behaviors evolve in a species over time) 4 Steps: |
1. (Mutations create Variation)
2. (Unfavorable mutations hamper reproduction & are selected OUT) 3. (Reproduction & mutation continue) 4. (Adaptive mutations are favored & spread thru the population) |
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Convergence
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-similar features that evolved separately
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Contrast with homology-
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features based on common ancestry – seal’s flippers and your arm
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Analogy-
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Similar function
(my arm & elephant’s trunk) |
