1. Evolution
The Spice of Life

2. Evolution
The change in a population’s genetic makeup through successive generations.

3. Microevolution -vs- Macroevolution
Micro (meaning small): describes the small changes that occur within a population
Macro (meaning large): describes long-term, large-scale evolutionary changes through which a new species form from ancestral species and other species are lost through extinction

6. Natural Selection
This occurs when some individuals of a population have genetically based traits that increases their chances of survival and their ability to produce offspring with the same traits.
3 things are needed for evolution by natural selection…

7. 1. Genetic Variability for a trait 2. The trait must be heritable 3
1. Genetic Variability for a trait 2. The trait must be heritable 3. The trait must lead to Differential Reproduction

8. Differences in the DNA between individuals in the same species
Genetic Variability
Differences in the DNA between individuals in the same species
Example: Brown hair –vs- Blond hair

9. Must be passed down from one generation to the next
Heritable
Must be passed down from one generation to the next
Example: Eye color or Hair color can be passed from parents but tattoos or a learned skill cannot

10. Differential Reproduction
The differences between individuals within a species that affects the ability of an individual to mate or reproduce
Example: A polar bear born with genes making his fur dark in color cannot survive as well as one with white fur, it would not be as healthy, it may not survive or be able to mate

11. Mutation
Rare, random changes in number or structure of DNA which gets passed down to offspring
Most of the time it is not beneficial (diseases, birth defects, cancer)
Sometimes it does not help nor harm the individual (birth marks, cleft chin)
Rarely it is beneficial

12. Adaptation
Any heritable trait that enables organisms to better survive and reproduce within its environment
Also known as an adaptive trait

13. Speciation Occurs when two species arise from one
A new species is formed when some members of a population can no longer breed with other members to produce fertile offspring

16. Geographic Isolation
This happens when different groups of the same population are isolated from each other for a long time Generally due to migration or an environmental barrier

17. Reproductive Isolation
When mutations and natural selection affect the isolated populations (which are no longer breeding with each other)
Example: different mating/pollinating seasons

18. Niche
A species’ way of life or functional role in a community or ecosystem and involves everything that affects its survival and reproduction
This means that it isn’t just what it does but also what is done to it (a mouse eats a nut but is also eaten by a fox)

19. Artificial Selection
Humans choose which traits are considered desirable and selectively breed individuals with the desired traits
Crops, livestock, pets