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Lab 6. Overview  Instructor collects lab. 5 write up and checks pre-labs. in lab notebook  Discussion of microbial spp. rich. write up.  Hardy-Weinberg.

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Presentation on theme: "Lab 6. Overview  Instructor collects lab. 5 write up and checks pre-labs. in lab notebook  Discussion of microbial spp. rich. write up.  Hardy-Weinberg."— Presentation transcript:

1 Lab 6. Overview  Instructor collects lab. 5 write up and checks pre-labs. in lab notebook  Discussion of microbial spp. rich. write up.  Hardy-Weinberg & Other Background.  Set up gels, examine blood smear slides, load samples, begin electrophoresis & then begin Simbiotic simulation  Compile electrophoresis data as a class.  finish Simbiotic simulation & in-class exercise  Examine plant cultures.  Discuss independent project & typed Lab. 6 write up due next week with instructor.

2 SIMPLE SITUATION = NO EVOLUTION  no mutation  no gene flow  no genetic drift  no assortative mating  no natural selection Modeling Evolutionary Change

3 Hardy-Weinberg  Hardy-Weinberg Theorem = predicts genotype frequencies (based on allele frequencies) in a population when it is NOT evolving. Allele Frequency Abbreviations p = frequency of A in the pop. q = frequency of a in the pop. [ % of A allele + % of a allele = 100% ] p + q = 1

4 Hardy-Weinberg  Hardy-Weinberg Theorem = predicts genotype frequencies (based on allele frequencies) in a population when it is NOT evolving. Hardy-Weinberg Equation(s) p 2 = frequency of AA in the pop. 2pq = frequency of Aa in the pop. q 2 = frequency of aa in the pop.

5 Is a Pop. at Hardy-Weinberg?  Pop. of 100 with 20AA, 20Aa, 60aa  Step 1–calculate the allele frequencies For 20AA, 20Aa, 60aa then freq. A = 0.30 = p freq. a = 0.70 = q  Step 2– plug into H.-W. equations p 2 = (0.30)(0.30) = 0.09 2pq = 2(0.30)(0.70) = 0.42 q 2 = (0.70)(0.70) = 0.49

6 Is a Pop. at Hardy-Weinberg?  Pop. of 100 with 20AA, 20Aa, 60aa  Step 3– multiply freqs. by pop. size p 2 = 0.09  100(0.09) = 9 AA individ. expected 2pq = 0.42  100(0.42) = 42 Aa ind. expected q 2 = 0.49  100(0.49) = 49 aa ind. expected  Step 4– compare observed and expected individuals (  2 statistical test) 20AA, 20Aa, 60aa  9AA, 42Aa, 49aa

7 Electrophoresis

8 Human Variation, Approx. Circa 1491  Humans do exhibit substantial genetic variation, and some of it is geographically patterned, but none diagnostically coincides with “races.”

9 Human Variation, Approx. Circa 1491 Allele frequencies vary regionally, so why wouldn’t this be enough to identify “biological” races?

10 Human Races  Race (biological definition) – distinct group of individuals of the same species sharing one or more constant genetic features that distinguish them from others within the species. Rarely used. [= No human biological races.]  Race (dictionary definition) – a family, tribe, group, or nation descended from the same individual or having unity of descent. [?]  Human Race (sociological definition) – a socially recognized group assumed to reflect ancestry; members are recognized based on certain physical and/or ancestry characteristics (e.g., skin color; having one ancestor categorized as a member of a race).  Recognized races vary among cultures & historically.

11 Today’s Activity Reminders  READ the instructions (  ) in the manual.  All the data from all the gels will be combined to form the data that all students will analyze for the exercise due in Lab 7.  Do not overpipette. (Don’t push plunger beyond “the stop.”)  Do not pierce the bottom of the gel well.  Do not use Kimwipes on microscope lenses.  The simulation provides a graph of allele frequencies showing BOTH alleles.  Obtain your unpaired X 2 -test P-value using the online site on the course website

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