1. Mechanisms of Evolution
P. 105
EQ: How does evolution happen?
Natural Selection
Genetic Drift
Gene Flow
Mutation
Recombination

3. Natural Selection Produces changes in POPULATIONS, not individuals
Process by which random evolutionary changes are selected for by nature in a consistent, orderly, non-random way
Organisms best adapted to their environment have a better chance of surviving and reproducing
Produces changes in POPULATIONS,
not individuals

4. Natural Selection
Organisms with traits that are better suited for a specific environment are called the “fittest” because their traits are best fit for their environment
Because their traits are best suited for their environment, the most fit individuals will tend to survive more often than others with less-desirable traits for their environment
Because they are more likely to survive, they are more likely to reproduce a lot (live longer)
This which will pass their better–suited traits on to future generations

5. Natural Selection Elements of natural selection: inherited variation
production of large # of offspring that won’t all survive & finite supply of environmental resources result in competition
Adaptation
Descent with modification occurs over time
“survival of the fittest”
A trait that helps an organism survive and reproduce, and can be passed down to it’s offspring, is called an adaptation.

6. Who will survive? Why?
Predict the amount (%) of light and dark individuals in the moth population.

7. Industrial Revolution happens…
Pollution was sent into the atmosphere. This killed the lichen that lived on the tree trunks. Soot also collected on the tree trunks. These 2 events caused the tree trunks to darken.

8. Who will survive? Why? How did you do??
Before the Industrial Revolution, about 99% of the moths were light.
In just 50 years after the Industrial Revolution began, 98% of the moths were dark.
Explain why this happened. Your answer should include a discussion of predation, survival, and inherited traits.
Predict the amount (%) of light and dark individuals in the moth population.

10. Speciation 2 species arise from one (wolf → dogs)
Requires Reproductive Isolation
Geographic – physically separated
Sexual Selection Differences – different times/rituals
Anatomical – they have to fit (think about a mouse & elephant…)
Allopatric Speciation - occurs when 2 or more populations of a species are geographically isolated from each other
Allele frequencies in these populations change
Members of each population become so different that they can no longer reproduce
Adaptive Radiation - when multiple species have a common ancestor (ex: Darwin’s Finches)

11. Natural Selection
Domesticating dogs – wild dogs were trained by man and bred (artificial selection) for desired traits. After a few generations of this, the wild dogs were not able to breed with the domesticated dogs – this means the domesticated dogs are a new species