1. Nature of Science

2. Theory:
An explanation for many related observations based on extensive scientific and experimental evidence in many conditions.

3. Science Religion

4. Microevolution vs. Macroevolution
Objective 1: Distinguish between the process of evolution (microevolution) and theory of evolution (macroevolution).

5. Evolution: (Microevolution)
Definition: the change in gene frequency of a population over time.
Evolutionary Theory: (Macroevolution)
The theory that life originated from one common unicellular ancestor and became diverse through natural selection and speciation.

6. Necessary Vocabulary Variation:
differences between individual members of a population. (Physical, behavioral, biochemical,etc)
Remember: Variation occurs from...
Genetic Mutations
Crossing Over
Independent Assortment
Fertilization

7. Necessary Vocabulary Adaptation:
inherited trait that increases an organism's chances of survival and reproduction in a particular environment.

8. Necessary Vocabulary Species:
An interbreeding, or potentially interbreeding, population that produces healthy, fertile offspring.

9. Necessary Vocabulary Population:
A group of organisms of the same species living in a specific area.

10. Story Time
The ancestors of giraffes had short necks. In order to eat leaves high up in the trees, individuals had to stretch their necks. As a direct result of this activity, the offspring of these individuals had longer necks. They, too, stretched their necks to reach even higher leaves, and transmitted their even longer necks to their offspring. Over time, as a result of the striving of individual giraffes, modern-day giraffes have very long necks.

11. Story Time
The ancestor of modern giraffes would have been a mammal with a short neck. In the ancestral population, a mutation arose that lengthened the neck of any animal that happened to harbor the mutation. These individuals were able to reach leaves higher in the trees than were other individuals. As a result, they were able to eat more and produced more offspring. Gradually, the long-neck mutation spread through the population. Sometime later, another mutation arose, which lengthened necks even more, and it spread through the population in a similar manner. Eventually, a number of mutations, each of which helped lengthen necks, spread throughout the population, resulting in the long necks we see today.

12. Objective 2: Describe and Identify the conditions necessary for natural selection to occur.

13. ***Natural Selection***
In 1859, after 15 years of observations and research, Charles Robert Darwin published On the Origin of Species. In this book, he introduced his "Theory of Evolution" based on Natural Selection.

14. ***Natural Selection***
This theory states that the following conditions must exist for evolution to occur...
There must be VARIATION in a population.
There is a change in the environment. (The video calls this… Struggle for existence)
Those organisms with favorable variation survive.
Individuals who survive, reproduce, and pass on the favorable variation to their offspring.
***Adaptations occur because of Natural Selection***

15. Natural Selection vs. Artificial Selection
Obj. 4: Compare & contrast natural and artificial selection.

16. Natural Selection vs. Artificial Selection
Natural Selection: conditions in nature determine what survives and reproduces.
Resulting adaptations allow better survival in the organisms' natural environment.
Example:
Peppered Moth
Darwin’s Finches
White Lizards of New Mexico

17. Natural Selection vs. Artificial Selection
Artificial Selection: humans decide what survives and reproduces.
Resulting adaptations serve the needs of humans.
Examples:
Farmers breed cows to produce more milk.
Humans breed horses for quickness and strength.
Genetically Modified Foods

18. Speciation Obj. 6: Describe a scenario where natural selection leads to speciation.

19. Speciation
What is speciation?
The evolution of one or more species from an original ancestor species.

20. Speciation What are the three-steps in order for speciation to occur?
Step 1: Isolation of population
Step 2: Adaptation/Evolution
Step 3:. Reproductive Isolation

21. Evidence for Evolution Obj
Evidence for Evolution Obj. 7: Identify & explain evidence of evolution including trends in history of life on earth.

22. Evidence for Evolution
Degree of relatedness between two species depends on how long ago they shared common ancestors. To determine relatedness, scientists can use:
Comparative Anatomy
Comparative Embryology
Comparative DNA
Fossil Records

23. Comparative Anatomy Homologous Structures:
Body parts that have the same general structure but different functions.
Due to common ancestors adapting to different environments
Examples: (change in notes)
Human arm, whale fin and bat wing

24. Comparative Anatomy Analogous Structures:
Body parts that have the same function but do not have a similar structure
Due to similar environments and lifestyles
Not common ancestors
Examples: Insect wings and Bird wings

25. Comparative Anatomy Vestigial Structures Genetic “Leftovers”
Often smaller in size
Often disused
No longer hold any valuable adaptation for survival
Suggest structures of common ancestry
Examples: tail bones, human appendix, body hair, goose bumps, wisdom teeth, hip bones in snakes, etc.

26. Comparative Embryology
Study of early stages of organism development.
Embryos of related organisms develop similarly.

27. Comparative DNA DNA Comparisons
Comparing DNA to determine relationships
The more similar DNA sequences are in organisms, the more related those organisms are.
Examples:
Hemoglobin – carries oxygen
Cytochrome C – enzyme involved in cellular respiration

28. Fossil Records
Fossils are the remains of a living thing that have been preserved in rock
Show changes in organisms over time
Ancestors
Transitional species
By dating the rock, scientists can tell when the organism was alive.
Also gives clues to how surroundings have changed over time
Difficulty: fossil record is incomplete

29. Fossil Records Cont… Rock Layers Mass Extinction
Age of fossils can also be determined by the rock layer in which they are found.
Older rocks are found on the bottom
Younger rocks are found closer to the top
Mass Extinction
When lots of fossils suddenly disappear
Usually evidence of environmental change
KT extinction (dinosaurs)