1. Hardy- Weinberg Equilibrium
What Happens if it doesn’t

2. Hardy -Weinberg
Under certain conditions the frequency of an allele will remain the same

3. Hardy -Weinberg No Mutation No immigration or emigration
Large population
No Natural Selection
Random Mating

4. Hardy -Weinberg Use p & q to represent allele frequency
P2 +2pq + q2 = 1.00 (100%)

5. Disruptions to Equilibrium
Mutations
Could produce new alleles (spontaneous)
Hard to eliminate harmful recessives
If helpful become part of population

6. Disruptions to Equilibrium
Migration
Emigration – exit
Immigration – into

7. Disruptions to Equilibrium
Genetic drift
Allele frequencies change
Happens in small population
Leads to no variation & possible extinction

8. Disruptions to Equilibrium
Non random mating
Geographic proximity
Many species have mate selection

9. Disruptions to Equilibrium
Natural selection
stabilizing – selects for the average
directional – selects for extreme
disruptive–selects for either end
sexual – choose mates

13. Concepts of species morphological based on looks
- what look like 2 different species can breed & produce fertile off spring

14. Concepts of species
biological – populations of organisms that can breed & produce fertile offspring, but do not breed with other groups

15. Concepts of species Modern – single type of organism that are
morphologically similar, can interbreed & produce fertile
offspring

16. Types of speciation Allopatric speciation
Results because a physical barrier is present

17. Types of speciation Sympatric Speciation
Results when there are no barriers, from natural selection, mutation and genetic drift

18. Isolation Mechanism geographic – physical separation (island & rivers)
2. Reproductive – unsuccessful breeding

19. Reproductive isolation
Post- zygotic –
after fertilize
offspring can’t
reproduce
Ex: mule, seedless grape

20. Reproductive isolation
Pre – zygotic
before fertilize
Ex: mating times

21. Rates of Speciation
gradual – slow shift in the forms that are seen punctuated – sudden shift in the forms seen in the fossil record