1. Theory of Evolution

2. Evolution
Evolution is the change in allele frequencies in a population over time.
Most fundamental concept in Biology. You cannot understand all the parts of Biology without understanding evolution.

3. Remember alleles? Example: AA, Aa, aa
Alleles are the different variations of a particular genetic trait.
Allelic frequency deals with how often a particular allele appears in a population.
Example: AA, Aa, aa

4. Allele Frequency Practice
Bob has 5 flowers. If each flower has 2 alleles, how many total alleles for the population?
If each flower is heterozygous (Aa), how many of the alleles are dominant?

5. Charles Darwin
the theory evolution proposed by Darwin explains how evolution works.
He realized that there is a struggle for existence among individuals.

6. Jean Baptiste Lamarck French Naturalist
1809- published ideas on evolution

7. Lamarck’s Hypothesis
During organism’s lifetime, physical features increase or decrease in size based on use disuse
Organisms pass down acquired traits to offspring

8. Believed that those parts of the body used extensively would become bigger and stronger and would be passed to offspring.

10. Those body parts that were not used would disappear
Legless salamanders

11. Thomas Malthus - 1798 Pop. growth limited by disease, famine, war
Human population increasing faster than supply of resources

12. Charles Lyell Leading geologist of Darwin’s time.
Believed the Earth was very old and had changed slowly over long periods of time.

13. Darwin’s Discoveries
Darwin collected 13 types of finches that, although quite similar seemed to be different species.
Some were unique to individual islands while others were on two or more islands that were close together.

14. Natural Selection
variations within same species enable some to survive and reproduce, while those with other variations did NOT survive and reproduce.
pass these variations to offspring.
“Survival of fittest”
Fitness – ability of an organism to survive & reproduce in its specific environment

15. FIT OR NAH

16. Main points of Darwin’s theory of natural selection:
Genetic variations in populations
Overproduction of offspring– struggle for existence
Organisms best adapted will survive, reproduce and pass traits to next generation.

17. Darwin’s 5 points Write in summary section
Population has variations.
Some variations are favorable.
More offspring are produced than survive
Those that survive have favorable traits.
A population will change over time.

18. NS against? ________ for? __________
Variations (2)?_____ Struggle to survive? ___ Trait that helped? ____ Pop. Over time? ____