Where did Mrs. Barker come from?

*EVOLUTION: The process of change over time*

*Species: a group of organisms that share similar characteristics and can reproduce among themselves to produce fertile offspring.*

***Write down the 4 conclusions Darwin Came to***

**Adaptation: A trait that helps an organism survie and reproduce**

**Natural Selection: Process by which individuals that are better adapted to their environment are more likely to survive & reproduce than other members of the same species.**

**Variation: Inherited traits that make an individual different from other members of its species.**

evolution of populations

**3 sources of genetic variations:

1. Mutations: Change in the genetic material of a cell

2. Genetic Recombination - during sexual reproduction each chromosome in a pair moves independently during meiosis. In humans, this can produce over 8,000,000,000 gene combinations.

3. Lateral gene transfer - passing of genes from one organism to another (not including offspring)

**Gene Pool: consists of all genes, including all the different alleles, that are present in a population.**

**GENETIC DRIFT: VARIATION IN THE RELATIVE FREQUENCY OF DIFFERENT GENOTYPES IN A SMALL POPULATION, OWING TO THE CHANCE DISAPPEARANCE OF PARTICULAR GENES AS INDIVIDUALS DIE OR DO NOT REPRODUCE.**

**Hardy-Weinberg Principle - states that allele Frequencies will remain constant of have genetic equilibrium, unless actos cause those frequencies to change.**

**5 conditions of the Hardy-Weinberg principle**

1. Random Mating

2. Very large population

3. No movement in or out of population

4. No mutations

5. No natural selection

*Reproductive isolation - when 2 populations no longer interbreed. Can result in the evolution of 2 separate species. Can be behavioral, geographic or temporal.