1.  Green color (G) is dominant to white color (g) in turtles.  In a population of 200 turtles, 13% are white. A) What are the allele frequencies? B) What percentage of each genotype are in this population? C) How many turtles are heterozygous?

2.  G= Greeng= white  White = 13% = 0.13 = gg= q 2  √0.13=√q 2 A) q = 0.36 then p = 0.64 B) GG = p 2 = (0.64) 2 =0.4096= 40.96%  Gg = 2pq= 2(0.64)(0.36)=0.4608= 46.08%  gg = q 2 = (0.36) 2 = 0.1296= 12.96% C) (.4608)(200) = 92 turtles are heterozygous

3.  A scientist has studied the amount of PTC tasters in a population. PTC tasting is dominant. From one population, 500 individuals were sampled. The scientist found the following individuals: AA = 110, Aa = 350; aa = 40.  Calculate the genotypic and allelic frequencies for the PTC gene at this population.  Determine the genotypic and allelic frequencies expected at Hardy-Weinberg equilibrium using the homozygous recessive. Is this population in Hardy-Weinberg equilibrium? Is the population evolving?

4.  AA = 110, Aa = 350; aa = 40.  AA = 110/500 = 0.22; Aa=350/500 = 0.70 ; aa= 40/500= 0.08  A=110 + 110 + 350 = 570/1000 = 0.57;  a = 40 + 40 + 350 = 160/1000 = 0.43

5.  p=A= PTC taster q= a = PTC non-taster  40/500= 0.08 = PTC non-taster = aa= q 2  √0.08=√q 2  q = 0.28 then p = 0.72  RR = p 2 = (0.72) 2 = 0.52 = 52.00%  Rr = 2pq = 2(0.72)(0.28) = 0.40= 40.00%  rr = q 2 = (0.28) 2 = 0.08 = 8.00%

6. Ms. Kim H. Biology

7. 1. Geographic isolation 2. Reproductive barriers (isolation) 3. Change in chromosome numbers through mutation 4. Adaptive radiation (example of divergent evolution)  Speciation = formation of NEW species

8. A. harrisi A. leucurus Hello over there Geographic Isolation

9. Two general modes of speciation determined by the way gene flow among populations is initially interrupted: Geographic and Reproductive Isolation Speciation can occur in two ways: ◦ Geographic: Allopatric speciation (means “other”)  a genetic isolation WITH a geographical barrier; new group isolated from its parent population ◦ Reproductive: Sympatric speciation (means “together”)  genetic isolation WITHOUT a geographical barrier; a reproductive barrier isolates population in SAME habitat

10. Allopatric speciation Sympatric speciation http://bcs.whfr eeman.com/the lifewire/content /chp24/24020 01.html

11. http://www.pbs.org/wgbh/nova/evolution/evolution-action-salamanders.html

12. Reproductive Isolation  biological factors (barriers) that stop 2 species from producing viable, fertile hybrids  Two types of barriers ◦ Postzygotic “after the zygote”  Zygote can NOT develop ◦ Prezygotic “before the zygote”  Sperm and egg can not fuse

15. Pre-Zygotic Barriers

16.  2 species encounter each other rarely, or not at all, because they live in different habitats, even though not isolated by physical barriers Sympatric: Habitat Isolation

17.  Species that breed at different times of the day, different seasons, or different years cannot mix their gametes Sympatric: Temporal Isolation Late Winter Late Summer

18.  Courtship rituals and other behaviors unique to a species are effective barriers Sympatric: Behavioral Isolation http://wps.aw.co m/bc_campbell_ biology_7/26/66 61/1705356.cw/ index.html

19.  Morphological differences can prevent successful mating  Related species may attempt to mate but CAN’T  anatomically incompatible  Sperm = transfer Sympatric: Mechanical Isolation Mating organs don’t fit

20.  Sperm of one species may not be able to fertilize eggs of another species  Ex: specific molecules on egg coat adhere to specific molecules on sperm Sympatric: Gametic Isolation

21. Post-Zygotic Barriers

22.  Genes of the different parent species may interact and impair the hybrid’s development  Hybrids are very weak and/or underdeveloped Reduced Hybrid Viability Salamander hybrid shows incomplete development

23.  Even if hybrids may live and be strong, they may be sterile Reduced Hybrid Fertility

24.  Polyploidy is presence of EXTRA sets of chromosomes due to accidents during cell division ◦ ex: “nondisjunction”  It has caused the evolution of some plant species  More common in plants than in animals