1. Ch. 15 Evolution – Change Over Time
QUESTIONS OF THE DAY
What is natural selection?
How do you know what a dinosaur eats? What would you be looking at?
Do you think a species gets better at doing something over a period of time? Why or why not?
Do you look like any of your grandparents? Why or why not?
What do you think would happen if a good trait were to show up in a population? What would need to happen for it to stay in the population?

2. Ch. 15 Evolution – Change Over Time
History of Evolution
Charles Darwin proposed the theory of evolution by natural selection.
Natural selection is the driving force behind evolution.
Cause and effect relationship
Galapagos Islands off the coast of Peru in South America
Darwin worked with finches.

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5. Ch. 15 Evolution – Change Over Time
Natural Selection
Term: survival of the fittest. (Reproduction)
FIT: Better suited to live in the environment.
(positive adaptations)
Reproduction is essential to pass the positive traits on to offspring.
Organisms with the most favorable traits are better suited to survive and pass on genes.
Least favorable traits will die with the organism. Therefore, the organism will not pass on the genes

6. Ch. 15 Evolution – Change Over Time
Over time, good traits accumulate in a population.
Good traits stay, bad traits go away. (typically)

7. Ch. 15 Evolution – Change Over Time
In the event of a Zombie Apocalypse, the humans with the best traits that are most suited for the environment will survive and pass their genes on to their children.
I don’t have to outrun the zombies. I just have to outrun you in order to pass on my strategy genes to my children.

8. Ch. 15 Evolution – Change Over Time
Selective breeding = breeding plants and animals for specific traits
Sexual selection = mate picks desired traits.

9. Ch. 15 Evolution – Change Over Time
Descent with Modification
All organisms are derived from existing organisms with slight changes.
Modification by Natural Selection
As the environment changes, fitness changes and new adaptations will arise.

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13. Ch. 15 Evolution – Change Over Time
Evolution: The Evidence
FIVE pieces of evidence for evolution.
Fossil Record
Comparative Anatomy
Analogous Structures
Vestigial Structures
Embryological Development

14. Ch. 15 Evolution – Change Over Time
Fossil Record
Compare extinct (dead) with extant (still surviving) organisms
Shows descent with modification

15. Ch. 15 Evolution – Change Over Time
Comparative anatomy
Homologous structures = structures that are similar due to a common ancestor.
Ex. Arm bones of vertebrates (humerous, radius, ulna)
By comparing the traits of organisms, a common ancestor can be established

16. Ch. 15 Evolution – Change Over Time
Overtime, organisms adapt to their changing environment.
Horses were once the size of dogs.
Overtime, the horse grew larger and stronger.

17. Ch. 15 Evolution – Change Over Time
Analogous structures
Similar features due to a common environment NOT a common ancestor.
Similar niche
Ex. Fish and Dolphin tails

18. Ch. 15 Evolution – Change Over Time
Vestigial structures
Remnants of evolutionary past.
Old structures that no longer serve a purpose.
Ex. Appendix, tailbone, wisdom teeth, tonsils.

19. Ch. 15 Evolution – Change Over Time
Comparative biochemistry
DNA
RNA
Amino acid based protein
ATP energy
Phospholipid bilayer
Universal genetic code

20. Ch. 15 Evolution – Change Over Time
Comparative biochemistry
98% of human DNA is the same as a chimpanzee’s genetic code

21. Ch. 15 Evolution – Change Over Time
Embryological development
Similar step by step development of the embryo.

22. Ch. 15 Evolution – Change Over Time
Geographic Distribution
Organisms evolve to fill niches in environment (Dingo and Coyote)
Dingos live in the outback of Australia
Coyotes live in a similar environment in the US
Both can breed with one another.

23. Ch. 15 Evolution – Change Over Time
Convergent Evolution
Different organisms developing similar traits to fill a similar niche.
Killer whale and a Great White Shark
Analogous structures

24. Ch. 15 Evolution – Change Over Time
Divergent Evolution
Organisms adapt to live in different environments and develop different traits. (different niche)
Blue whale and killer whale or Great White Shark and whale shark.
Homologous structures

25. Ch. 15 Evolution – Change Over Time
Co-evolution
Organisms changing in a close relationship.
Parasite/host
predator/prey
flower/pollinator