1. What is the difference between a scientific law, theory, and hypothesis?

2. There is no “proof” in science
Hypothesis
A statement that is based on observation that can be tested.
Theory
A well supported explanation of natural phenomenon
Law
Describe how things happen but don’t explain them.
There is no “proof” in science
New observations can change current understanding

3. LaMarck Organisms are adapted to their environments
through acquired traits
change in their life time
Use & Disuse organisms lost parts because they did not use them — like the missing eyes & digestive system of the tapeworm
Perfection with Use & Need the constant use of an organ leads that organ to increase in size — like the muscles of a blacksmith or the large ears of a night-flying bat
transmit acquired characteristics to next generation
Lamarck noted how well-adapted organisms were to their environments, and believed that fossils could be understood as less perfect forms which had perished in the struggle for increasing perfection. He explained adaptation as a result of change caused by environmental pressures.

4. Voyage of the HMS Beagle
Travels around the world
makes many observations of natural world
main mission of the Beagle was to chart South American coastline
Robert Fitzroy
After graduation Darwin was recommended to be the conversation companion to Captain Robert FitzRoy, preparing the survey ship Beagle for a voyage around the world.
FitzRoy chose Darwin because of his education, his similar social class, and similar age as the captain.
Darwin noted that the plants and animals of South America were very distinct from those of Europe

5. How did Darwin come up with this?

6. Cut to the videotape…
Darwin: ”The black Lava rocks on the beach are frequented by large (2-3 ft), disgusting clumsy Lizards. They are as black as the porous rocks over which they crawl & seek their prey from the Sea. I call them 'imps of darkness'. They assuredly well become the land they inhabit.”

8. Correlation of species to food source
Seed eaters
Flower eaters
Insect eaters
Adaptive radiation

9. In historical context
Other people’s ideas paved the path for Darwin’s thinking
competition:
struggle for survival population growth exceeds food supply
land masses change over immeasurable time

10. Natural Selection
Overproduction … Variation Competition

11. Overproduction

12. Variation

13. Competition

14. How does it work? Overproduction Variation Competition Selection…
Organisms have more offspring than can survive
Variation
Not all organisms are the same
Competition
There isn’t enough for everyone, so who will get what they need?
Selection…

15. The “selection” part of Natural Selection
Variation in traits
Selection
Heredity
End result?
More organisms
with the successful
trait

16. Example: Peacocks

17. E. coli long-term evolution experiment
50,000 generations - 25 years
1 strain Evolved the ability to use citrate

18. This is not just a process of the past… It is all around us today
Artificial Selection
This is not just a process of the past…
It is all around us today

19. Lots of hidden variation comes out!
Selective Breeding
Lots of hidden variation comes out!
AP Movie—Ch 22: Artificial Selection

20. Evolution Descent with modification
The process of change in all forms of life over generations
Change in the frequency of a trait
Eo: mya Plio: 12-6 mya

21. Bellwork 2/5/2013
What is the primary mechanism of evolution?
How do we know if evolution is happening in a species or population?

22. Evolution Descent with modification
Millions of years ago 50
100
150
200
250
300
350
400
450
500
550 60 55 45 40 35 30 25 20 15 10 5
Equus
Hyracotherium
Mesohippus
Merychippus
Nannippus
Body size (kg)
Evolution
Descent with modification
The process of change in all forms of life over generations
Change in the frequency of a trait
Eo: mya Plio: 12-6 mya

23. Where does Variation come from?
Mutation
random changes to DNA
errors in mitosis & meiosis
environmental damage
Sexual reproduction
mixing of alleles
genetic recombination
new arrangements of alleles in every offspring
new combinations = new phenotypes

24. LaMarckian vs. Darwinian view
in reaching higher vegetation giraffes stretch their necks & transmits the acquired longer neck to offspring
Darwin
giraffes born with longer necks survive better & leave more offspring who inherit their long necks 

25. Other mechanisms of evolution
Migration
Mutation
Genetic Drift

26. Keep in mind Evolution does not always mean a new species
Some changes are minor
When speciation occurs, it happens over millions of years

27. Evolution Descent with modification
The process of change in all forms of life over generations
Change in the frequency of a trait
Eo: mya Plio: 12-6 mya

28. Evolution: What it doesn’t describe
The origin of life
The definition of species
The age of the earth
The beginning of the universe

29. Evidence
Fossils
Tiktaalik roseae

30. Fossil Record
Shows organisms transitioning from less complex to more complex

31. Evidence
Relative Dating
Radiometric dating

32. Transitional Species Ambulocetus
Ambulocetus – walking and swimming – 50 million years ago
Doradon– swimming – 35 million years ago
Evidence of a gradual change between a newer species and its ancestor

33. Transitional Species
Doradon– swimming – 35 million years ago
Evidence of a gradual change between a newer species and its ancestor

34. Vestigial Structures
Structures that do not serve a function and are similar to those found earlier organisms

35. Homologous Structures
Structures that related species have inherited from a common ancestor

36. Homologous Structures
Structures that related species have inherited from a common ancestor

37. E. coli long-term evolution experiment
50,000 generations - 25 years
1 strain Evolved the ability to use citrate

38. DNA

39. itol.embl.de