1. Summary of one-locus fitness models FitnessesOutcome W Aa > W AA, W aa Stable polymorphic equilibrium with A and a W Aa < W AA, W aa Unstable equilibrium, which allele fixed depends on the initial frequencies W AA > W Aa > W aa Allele A fixed W AA < W Aa < W aa Allele A fixed All possible combinations of inequalities

3. FITNESS How do we measure fitness? Lifetime reproductive success: # mature offspring produced Survival # offspring per year Ability to acquire resources # mates LRS = Lifespan of organism X Reproduction rate X Survival of young to adulthood

4. Possible genotypes AA, Aa, aa Possible phenotypes (1) The neutral one, where the only class is {AA, aa, Aa}; (2) The separative one: {AA} {aa} {Aa}; (3) The Mendel dominant one: {AA, Aa} and {aa}; (4) {AA aa} and {Aa}. In case (4) the phenotypes can be identified with the numbers of different genes and then ϕ AA = ϕ aa = 1, ϕ Aa = 2. For this reason we call this phenotypical structure quantitative.

5. FitnessesOutcome W Aa > W AA, W aa Stable polymorphic equilibrium with A and a W Aa < W AA, W aa Unstable equilibrium, which allele fixed depends on the initial frequencies W AA > W Aa > W aa Allele A fixed W AA < W Aa < W aa Allele A fixed (1) The neutral one, where the only class is {AA, aa, Aa}; W 11 (AA)= W 12 (Aa)= W 22 (aa) (=1) Formal fitness coefficient

6. FitnessesOutcome W Aa > W AA, W aa Stable polymorphic equilibrium with A and a W Aa < W AA, W aa Unstable equilibrium, which allele fixed depends on the initial frequencies W AA > W Aa > W aa Allele A fixed W AA < W Aa < W aa Allele A fixed (2) The separative one: {AA} {aa} {Aa}; W 11 (AA), W 12 (Aa), W 22 (aa) Formal fitness coefficient

7. FitnessesOutcome W Aa > W AA, W aa Stable polymorphic equilibrium with A and a W Aa < W AA, W aa Unstable equilibrium, which allele fixed depends on the initial frequencies W AA > W Aa > W aa Allele A fixed W AA < W Aa < W aa Allele A fixed (3) The Mendel dominant one: {AA, Aa} and {aa}; W 11 (AA)=W 12 (Aa), W 22 (aa) Formal fitness coefficient

8. FitnessesOutcome W Aa > W AA, W aa Stable polymorphic equilibrium with A and a W Aa < W AA, W aa Unstable equilibrium, which allele fixed depends on the initial frequencies W AA > W Aa > W aa Allele A fixed W AA < W Aa < W aa Allele A fixed (4) {AA aa} and {Aa}. W 11 (AA)= W 22 (aa), W 12 (Aa) Formal fitness coefficient

9. Possible genotypes AA, Aa, aa Possible phenotypes (1)The neutral one, where the only class is {AA, aa, Aa};Trait: t 1 (2) The separative one: {AA} {aa} {Aa}; Traits: t 1, t 2, t 3 (3) The Mendel dominant one: {AA, Aa} and {aa}; Traits: t 1, t 2. (4) {AA aa} and {Aa}. Traits: t 1, t 2. Phenotype Trait

10. 1. Directional Trait Frequency Evolutionary change Types of selection in nature Old trait mode New trait mode

11. DIRECTIONAL SELECTION Darwin’s finches Severe drought 1976-1977 Killed plants with small seeds: birds with larger beaks survived better Geospiza fortis 10.5 mm11 mm Boag and Grant 1981 Trait

12. DIRECTIONAL SELECTION Peppered moth Biston betularia White form dominated pre-industrialized Britain Pollution killed white lichens Melanic (black) form increased to 90% of population w/in century With pollution controls, lichens returned and white form increased again

13. Trait Frequency 2. Stabilizing Most common: maintains status quo Types of selection in nature Trait mode

14. STABILIZING SELECTION Human birth weight Extreme light weight and extreme heavy weight both selected against 8 lbs Trait

15. Frequency 3. Disruptive Speciation Types of selection in nature Two different trait mode

16. DISRUPTIVE SELECTION Drosophila experiment Only flies with high or low numbers of bristles (chaetae) were allowed to breed

17. Fitness coefficients Alleles A, a Weight (Price) u(A), u(a) Zygote Trait (AA ) 2u(A) ( Aa ) u(A)+u(a) (aa ) 2u(a) T- optimal value of the trait T

18. Example for different relations between T, values u() of traits and trajectories

19. Cyclical environment Environmental state 1 (summer) Environmental state 2 (winter) T1T1 T2T2 Long environmental cycle

20. Examples trajectories fro cyclical environment in Aa,aa coordinates

21. Interaction between species Host-parasite case Mutualistic case

22. Host-parasite case T1T1 T2T2

23. Mutualistic case T1T1 T2T2

24. Simulation

25. Frequency depended selection

26. Fitness coefficients W AA =exp( ( T-2u(A) ) 2 /s) W aa =exp( ( T-2u(a) ) 2 /s) W Aa =exp( ( T-u(A)- u(a) ) 2 /s)