Unformatted text preview: Microevolution Microevolution Definition
Microevolution Microevolution: small changes in a species over time. Example: bacterial resistance to antibiotics. Main Concept of Microevolution
Main 1. You must have genetic variation. 2. You have environmental change. 3. A combination of forces will cause change. Other Key Concepts
Other 4. These forces include: isolation, migration, natural selection and mutation. 5. These factors will form a slow change of gene frequencies over time. What give us Genetic Variation
What Mutation: Change in an organisms DNA. Gene Shuffling: Mixing of genes during the process of reproduction. Mutation
DNA New Organism=New Traits
New Traits of Mom Traits of Dad
B blood A blood
No widows peak Widows Peak
Tongue Roller Tongue Roller
Brown Eyes Blue Eyes
Black Hair Blonde Hair Junior
Junior AB blood
No Widows Peak
Non Tongue Roller
Brown Hair Genetic Frequency
Genetic How often a particular trait shows up in a particular population.
Usually done by percentage. Peppered Moth
Peppered Peppered Moth
Peppered Peppered Moth Genetic Frequency
Peppered Year % of Light Moths % of Dark Moths 1 90 10 2 83 17 3 71 29 4 64 36 5 48 52 6 39 61 7 33 67 8 22 78 9 12 88 10 8 92 Natural Selection
Natural “Survival of the Fittest”
Organisms with genes that are suited for their environment survive and pass them on. Organisms with genes that are not suited for their environment die out and do not pass them on. Genetic Drift
Genetic Only take place in small populations.
Some traits will be randomly passed more then others therefore showing up more often within a population. Migration
Migration Movement of individuals in or out of a population. * Brings in new traits and genes.
* Makes organisms adapt to new environments. Isolation
Isolation A barrier forms between members of a population not allowing them to mate.
* Could be physical, temporal (reproduce at different times) or behavioral. Meadowlarks
Meadowlarks Eastern Western Islands
Islands Island Canyon Orchids
Mutations Add new traits into a population.
If those new traits are helpful then they will be kept in that population and passed on. ...
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