Free Classroom Resources from HHMI for Teaching Evolution, Part 2 Megan Stine [email protected] June 19, 2014 Evolution: Behind the Scenes Evolving Switches, Evolving Bodies • Film guides • Virtual lab • Classroom activities: – Using Genetic Crosses to Analyze a Stickleback Trait – Modeling the Regulatory Switches of the Pitx1 Gene in Stickleback Fish Evolving Switches, Evolving Bodies Film • http://www.hhmi.org/biointeractive/makingfittest-evolving-switches-evolving-bodies Which phenotype is dominant? • Assumption: single-gene trait, 2 alleles, normal dominance • Cross between a marine stickleback and one from Bear Paw Lake • Parents are homozygous • F is dominant, f is recessive Predict the results of the crosses 1st generation 2nd generation F F f Ff Ff f Ff Ff Pelvic spines present:absent = 1:0 0:1 F f F FF Ff f Ff ff Pelvic spines present:absent = 3:1 1:3 Sorting by Phenotype With pelvic spines Without pelvic spines Do the data support your hypothesis? • Sort the F1 cards: – Fish with pelvic spines – Fish without pelvic spines • Sort the F2 cards • Ratio of fish with:without pelvic spines in F1? 1:0 • Ratio of fish with:without pelvic spines in F2? 3.4:1 Was our initial assumption correct? Is this a single-gene trait? Was your hypothesis correct? Which phenotype is dominant? Virtual Lab Natural Selection in Humans • Film guides • Classroom resources: – Nature of Science – Mendelian Genetics, Pedigrees, and Chisquare Analysis – How Fibers Form – Population Genetics Natural Selection in Humans Film • http://www.hhmi.org/biointeractive/makingfittest-natural-selection-humans Mendelian Genetics Activity • • • • • Punnett squares Pedigree analysis Pedigree creation Chi-square analysis Data prediction • Important notes: – A is normal allele – S is sickle cell allele – AA has normal RBC phenotype – AS has sickle cell trait – SS has sickle cell disease Question #1: Intro Punnett A S A S AA AS AS SS • Chance of normal RBC in high and low oxygen? • Chance of SCD? • Chance of 3 children with SCD? • Chance of 2 children with sickle cell trait and 1 with SCD? • Child without SCD, what chance he/she has trait? 1/4 1/4 1/64 1/16 2/3 Question #6: Intro Pedigree • Genotype of: – 1st gen male? – 2nd gen daughter? – Individual #3? AS SS AS • If family moves to lowlands of E. Africa, 4/5 males will have two genetic advantages. What are they? Human Evolution Click & Learn Teacher Guides Holiday Lecture Series BioInteractive.org Coming in Fall 2014… Thank you for your time and attention! [email protected] Sign up for our newsletter at biointeractive.org Like us on Facebook!