1. SPECIATION pp

4. Speciation: forming a new species
Species: a group of organisms that can mate and produce fertile offspring that have the same number of chromosomes and similar morphology (body Structure)
There is no gene flow between different species

6. What would prevent gene flow?

7. MECHANISMS OF SPECIATION
Adaptive radiation: Populations adapt and fill every (micro)environment and habitat available

8. Genetic Drift: organisms become more similar within small populations and more dissimilar from the larger population

9. Disruptive selection: divergent evolution that most likely results in two new species

10. Allopatric speciation: caused by the physical separation of organisms (geographic isolation)

11. Sympatric speciation due to barriers of successful breeding (reproductive isolation)
a. prezygotic: before fertilization (i.e breeding times or home range)

12. b. postzygotic: after fertilization- results in infertile offspring (chromosome # doesn’t add up)