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Evolution
Diversity of Life
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Evolution
“Nothing in biology makes sense EXCEPT in the light of evolution.” Theodosius Dobzhansky
Charles Darwin in later years
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3. History of Evolutionary Thought
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4. Early Ideas On Earth’s Organisms
Linnaeus – 1st to group similar organisms and assign them Latin names
Two word name (Genus species)
Known as Binomial nomenclature
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Charles Lyell
Proposed theory of Uniformintarianism
Geological processes at uniform rates building & wearing down Earth’s crust
Proposed that the Earth was millions of years instead of a few thousand years old
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Principles of Geology
Published by Lyell Just Before The Beagle Set Sail & read by Darwin
Explained Geological Processes That Shaped The Earth
Helped Darwin Understand Sea Shells In The Andes Mountains At 12,000+ Feet
Expanded Earth’s Age
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7. Lamarck’s Theory of Evolution
Jean-Baptiste Lamarck, 1809
One Of First Scientists To Understand That Change Occurs Over Time
Stated that Changes Are Adaptations To Environment acquired in an organism’s lifetime
Said acquired changes were passed to offspring
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8. Lamarck’s Theory of Evolution
Idea called Law of Use and Disuse
If a body part were used, it got stronger
If body part NOT used, it deteriorated
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9. Lamarck’s Theory of Evolution
Inheritance of Acquired Characteristics
Proposed That By Selective Use Or Disuse Of Organs, Organisms Acquired Or Lost Certain Traits During Their Lifetime
These Traits Could Then Be Passed On To Their Offspring
Over Time This Led To New Species
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10. Lamarck’s Theory of Evolution
___________- Organisms Could Change The Size Or Shape Of Organs By Using Them Or Not Using Them
_________(muscular arms)
____________from stretching)
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12. Lamarck’s Theory of Evolution
__________________________
Traits Acquired During Ones Lifetime Would Be Passed To Offspring
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Clipped ears of dogs could be passed to offspring!

13. Lamarck’s Theory of Evolution
_____________________
Organisms Are Continually Changing and Acquiring Features That Help Them Live More Successfully In Their Environment
Example: ________________________________________________________
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Lamarck’s Mistakes
Lamarck Did NOT Know how traits were _______________________
Genes Are NOT Changed By Activities In Life
Change Through __________________________________________________
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15. Charles Darwin the Naturalist
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Voyage of the Beagle
Charles Darwin
Born Feb. 12, 1809
Joined Crew of HMS Beagle, 1831
Naturalist
5 Year Voyage around world
Avid Collector of Flora & Fauna
Astounded By Variety of Life
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17. Darwin’s Voyage of Discovery
A reconstruction of the HMS Beagle sailing off Patagonia.
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The Galapagos Islands
Small Group of Islands 1000 km West of South America
Very Different ________
Animals On Islands Unique
________
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The Galapagos Islands
___________off the coast of South America
________________________________________________
Each island had long or short neck tortoises
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The Galapagos Islands
Finches on the islands ____________________________
______________________where the available food was different (seeds, nuts, berries, insects…)
Finches had ______________adapted to their _________________________
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23. Darwin’s Observations & Conclusions
The Struggle for Existence
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Voyage of the Beagle
During His Travels, Darwin Made Numerous Observations And Collected Evidence That Led Him To Propose A ___________________About The Way Life Changes Over Time
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25. Darwin’s Observations
Patterns of Diversity were shown
Unique _________ in organisms
Species Not Evenly Distributed
Australia, Kangaroos, but No Rabbits
S. America, Llamas
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26. Darwin’s Observations
Both Living Organisms & Fossils collected
Fossils included:
__________
____________________________________
This species NO longer existed. What had happened to them?
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Evidence for Evolution – The Fossil Record
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Definition
_________ is the slow , gradual change in a population of organisms over time
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29. Darwin’s Observations
Left unchecked, the _____________________________, generation to generation
In nature, _________________in size
Environmental ____________________
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Darwin’s Conclusion
Production of more individuals than can be supported by the environment leads to a __________________________________
Only a fraction of offspring survive each generation
_________________
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31. Darwin’s Observations
Individuals of a population vary extensively in their characteristics with _____________________________.
Much of this variation between individuals is ______________.
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Darwin’s Conclusion
Individuals who inherit characteristics ___________are likely to leave more offspring than less fit individuals
Called _____________
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33. Darwin’s Theory of Evolution
The ______________________leads to a gradual change in a population, with favorable characteristics accumulating over generations _________________
New species evolve
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34. Ideas That Shaped Darwin’s Thinking
Thomas Malthus
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Population Growth
Thomas Malthus, 1798
Economist
Observed ________________________
Population size _________such as the Food Supply
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36. The Struggle for Existence
Malthus’ Influence:
____________________________________________________________
Each Species Struggles For:
Food
Living Space
Mates
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Population Growth
Malthus Reasoned That If The Human Population Continued To Grow Unchecked, Sooner or Later There Would Be Insufficient Living Space & Food For Everyone
Death Rate Will Increase To Balance Population size & Food Supply
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Population Growth
Darwin Realized Malthus’s Principles Were Visible In Nature
Plants & Animals ______________________________________________________
Most Die
If They Didn’t – Earth Would Be Overrun
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39. Darwin’s Theory of Evolution
Organisms Change Over Time
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40. Common Descent with Modification
Darwin proposed that organisms descended from ______________
Idea that organisms ________, diverging from a common form
Caused ___________
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Natural Selection
________for evolution
During the struggle for resources, ___________
Idea that at least some of the differences between individuals, which impact their survival and fertility, are ___________ .
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