1. Population Genetics
Population: a group of organisms of the same species living together in a given region and interbreeding.
Allele: Different forms of a gene for a trait.
Gene pool: the total of alleles present in a population

2. Sources of variation in a population
Mutations.
Genetic recombination (sexual reproduction)
Migration (Founder effect: new colony founded by only a few individuals)
Genetic drift (changes in a population’s genes that are happening randomly)
Speciation (formation of new species)

3. Hardy-Weinberg Law
The frequency of genes leading to a certain characteristic in a population does not change unless evolutionary forces act on the population.
No mutation
No natural selection
Random mating
Big population (no inbreeding)
No migration in or out of the population.

4. Evolution of species (speciation)
Divergent evolution: species become different over a long period of time.
Adaptative radiation (species spread out to new territories).
Convergent evolution: Different species undergoing similar adaptations and evolving more alike
Coevolution: two species evolve together, as they depend on each other
Extinction: Species disappear.
Gradualism: slow, gradual and even evolution.
Punctuated Equilibrium: no changes, punctuated with bursts of sudden evolution

5. Mechanisms of speciation
Allopatric speciation:
A geographical process splits or fragments a population such that the groups evolve separately and cannot interbreed.
Continental drift.
Sympatric speciation
Mostly in plants
Hybridization
Polyploidy
Autopolyploidy
Allopolyploidy

6. Isolating mechanisms Prezygotic barriers Postzygotic barriers
Ecological barriers
Behavioral barriers
Mechanical barriers
Gametic barriers
Postzygotic barriers
Hybrid inviability
Hybrid breakdown
Hybrid sterility

7. Adaptations: Camouflage

8. More camouflage

9. Adaptations: Warning coloration

10. Adaptations: Seasonal changes

11. Adaptations: Mimicry

12. Types of Natural Selection
Directional selection
Stabilizing selection
Disruptive selection

13. Hybrid animals