Darwin’s Theory of Evolution - 1
1. The History of Life
- Evolution______
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- Theory______
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- Fossil______
They are connected…
Flashback…
- The total variety of all the organisms in the biosphere = ______.
- What scientific explanation can account for the diversity of life?______
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Proof of Evolution
- Fossil Record – ______
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Theory of Pangaea
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2. Charles Darwin
- Charles Darwin
- The person who was most influential to our understanding of ______.
- In 1831, at age 22, he joined the crew of the ______as a naturalist for a ______year voyage around the world.
Darwin and the HMS Beagle
- During his travels, Darwin wrote ______of pages in his journals, ______pictures of the things he saw, and collected a vast amount of ______ that led him to propose a ______about the way .
Darwin’s Observations
- Why do ______have different animals even though they have similar ecosystems?
- ?
- ?
- How are these ______related to living species?
Galápagos Islands
- While on his voyage around the world aboard the HMS Beagle, Darwin spent about ______month observing life on the .
- There, he encountered some ______animals, such as ______and ______.
- The Galápagos Islands are ______together but have very ______climates.
Galápagos Tortoises
Galápagos Finches
Darwin’s Findings
- After his voyage, ______
3. Darwin Presents His Case
Darwin’s Findings
- After Darwin returned to England in 1836 ______
______.
- He did not rush to publish his ideas because ______
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Wallace’s Essay
- In 1858, another naturalist, Alfred Russell Wallace ______
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Origin of Species
- Suddenly, Darwin had incentive to publish the results of his work.
- In 1859 ______
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Evolution is a THEORY
- A theory______
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Keys to Darwin’s Theory
- .
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- .
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Vocabulary
- Ability of an individual to survive reproduce in its environment = ______.
- Any inherited characteristic that increases the chance of survival = ______.
What is Darwin’s Theory?
- Over time, natural selection ______
______.
- These changes ______.
- How does it work?
- ______suggests that each species has descended with changes, from other species over time.
- This idea suggests that ______
______.
Darwin’s Theory of Evolution - 2
4. Evidence of Evolution
Homologous Structures
- Structures, like the limbs of vertebrates, ______
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Homologous Body Structures
- Some homologous body structures ______
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Why Grow a Tail; or Legs…
- The human embryo has a ______ at 4 weeks; which disappears at about 8 weeks.
- Skinks are a type of lizard. In some species, ______ have become so small they no longer function in walking.
- One explanation: ______
______
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Similarities in Embryology
- .
Similarities in DNA
- .
Similarities in Karyotypes
- .
Artificial Selection
- In artificial selection, ______
______
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- Examples: ______
Hardy-Weinberg Principle
______
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- Remaining the same = ______.
Genetic Drift
- The ______in the frequency of alleles in a population.
- Usually affects ______.
Verifying Darwin’s Findings
- If Darwin’s theory is correct, ______
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- Tortoises adapted to different habitats as they spread from the mainland to the different islands. = ______= .
- Adaptive radiation ______
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- Additionally, if Darwin’s theory is correct you would also expect to find ______
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- Whales and sharks have a similar body design even though they are very different organisms (one is a fish; the other, a mammal) because they have independently adapted to living in a similar environment = .