1. Evolution

2. Evolution Change over time Change in allele frequency
The process by which modern organisms have descended from ancient organisms
Macroevolution—large changes
Microevolution—small changes

3. Charles Darwin
Darwin traveled on the HMS Beagle to the Galapagos Islands as ship naturalist
Made observations about how species change over time
Darwin observed that the characteristics of many animals and plants varied noticeably among the different islands of the Galapagos.

4. Darwin’s Theory Published On the origin of Species in 1858
Abandoned theory that species were perfect and unchanging
Argued that different variations are brought out through a process called natural selection

5. Natural Selection The Struggle for Existence
Members of each species compete regularly to obtain
Food
Living space
Other necessities of life

6. Natural Selection Survival of the Fittest
Fitness = result of adaptations
Adaptation = any inherited characteristic that increases an organism’s chance of survival
Over time natural selection results in changes in the inherited characteristics of a population.

7. Antibiotic-Resistant Bacteria

9. Natural Selection Descent with Modification
Each living species has descended from other species over time
Changes that increased ability to survive are maintained

10. Evolution of Populations
Population = group of individuals of the same species that live in the same area
Species = group of organisms that can breed and produce fertile offspring
Gene Pool = the combined genetic information of all the members of a particular population

11. Sources of Genetic Variation
Mutations
Changes in DNA sequence; results in different characteristics
Genetic Shuffling
Chromosomes move independently during Meiosis
Crossing-over swaps genes on homologous chromosomes

12. Hardy-Weinberg Principle
Relative Frequency of an Allele = number of times that allele occurs in a gene pool compared with the number of times other alleles occur
Genetic Equilibrium (constant allele frequencies) will be maintained unless one or more factors cause the frequencies to change

13. Conditions of Hardy-Weinberg
Random Mating
Large Population
No movement in or out of the population
No mutations
No natural selection