1. Evolution
“It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is the most adaptable to change.”
~Charles Darwin

2. Change in a species’ genetic makeup over time
Evolution
Change in a species’ genetic makeup over time
Theory (well tested explanation)
Charles Darwin

3. Before Darwin… Inheritance of Acquired Traits
(Jean Baptiste Lamarck)
Organisms acquired or lost traits based on use during its lifetime & passed to offspring

4. Collected specimens & fossils around the world
Beagle (1831)
Collected specimens & fossils around the world

5. GALAPAGOS ISLANDS Observed many organisms 97% of island is protected
High number of endemic species (species found only there)
97% of island is protected
Start video: 8:10 End Video:16:25
Finches – different beaks for different food
Tortoise – different shells for where food is found.

6. Galapagos island species of interest

7. 1859 – ORIGIN OF SPECIES Before DNA Introduced Artificial selection
Natural selection
Evolution

8. Nature provides variation, humans select variations that are useful.
ARTIFICIAL SELECTION
Nature provides variation, humans select variations that are useful.
Examples:
Farmers breeding best livestock
Domesticated dogs

9. NATURAL SELECTION
The traits that help an organism survive in a particular environment are “selected” for in nature

10. STEPS IN NATURAL SELECTION
Genetic variation
Difference in color, size, etc.
Genetic mutation (after Darwin)
Over population
Struggle to survive
Not enough resources
Successful reproduction
Well adapted live and reproduce

13. Start Video: 32:27 End Video: 41:52
Adaptation Video

15. EUROPEAN PEPPERED MOTHS
Rested on tree trunks
Moths rest with their wings folded down
Birds were predators

16. European Peppered Moths
Two color variations
Dark
Pale
Before 1850
Pale more common
By 1860
Dark more common

17. What happened in the 1850s? Trees covered in lichens Pale: blended
Dark: stood out
1850s – Industry
Soot covered trees
Dark: blended
Pale: stood out
Simulation

18. Natural Selection to Evolution
Insecticides – chemicals used to rid plants of unwanted insects
Antibiotics – treat bacterial infections
Work well before = now ineffective
Why?
Resistance

19. Populations evolve not individuals!

20. SUMMARY OF DARWIN’S THEORY
1. Organisms differ; variation is inherited 2. Organisms produce more offspring than survive 3. Organisms compete for resources 4. Organisms with advantages survive to pass those advantages to their children 5. Species alive today are descended with modifications from common ancestors

22. Two Types of evolution
1. Divergent – related species become more dissimilar 2. Convergent – unrelated species become more similar in appearance as they adapt to a similar environment

23. Homologous structures
Evidence of Evolution
Fossil Record
Homologous structures
DNA
Embryonic structures

24. Fossils changed between different layers of the earth
Fossil Record
Fossils changed between different layers of the earth
Youngest
Oldest

25. HOMOLOGOUS STRUCTURES
Structures with different mature forms that develop from the same embryonic tissue
Modified for specific function

26. Similar form & function, but are structurally quite different
ANALOGOUS STRUCTURES
Similar form & function, but are structurally quite different
Same habitat 26

27. DNA
Common ancestors =common DNA Greater # of DNA similarities = closely related

28. EMBRYONIC STRUCTURES Embryos may look more similar to adults
All vertebrates look similar as embryos
Stop at 9:10

29. Remnants of once useful structures
VESTIGIAL STRUCTURES
Remnants of once useful structures
Ex. – Whale
Hind limb bones
Ex. – Humans
Goosebumps
Start 4:10 finish and click on the 2/6 video and stop at 5:55 or so

30. Changes leading to formation of new species.
Speciation
Changes leading to formation of new species.
Populations evolve and become
reproductively isolated from
each other(members of two
populations cannot interbreed)
Behavioral isolation
Geographic Isolation 30