- Slides: 19
Are Humans Evolving? How would you know? Lisa Torres, Joan Miyazaki, Jeff Leips, Bill Collins, Phil Sokolove, (The Changlings)
Learning Objectives • Be able to define evolution • Understand factors that cause or lead to changes in allele frequency • Understand how changes in allele frequency are related to adaptation • Calculate phenotypic, genotypic, allele frequencies from “real” population data
Module Outline Three day module consisting of the following components. • Preclass assignment and readiness assessment test. • Class 1: Class Phenotype activity (phenotype, genotype and allele frequencies, H-W formula) • Class 2: Define evolution, Students work with real data • Class 3: Human evolution: are humans evolving? • Summative Assessment
Misconception Assessment Survey Instrument Give a number for each of the following from 1 to 5: 1 –agree 5 – disagree A. When one trait is dominant to another trait, it is generally also the most frequent trait in a population. B. Traits evolve in response to environmental change. C. Allele frequencies change in all of the individuals in a population in response to changes in the environment. D. Evolution is change in allele frequencies in a population over time. E. Evolution is change in heritable traits in a population over many generations. F. Evolution takes millions and millions of years.
Earlobe Attachment Free Attached
Earlobe Attachment Free (Dominant) Attached (Recessive)
Earlobe Phenotype Number Free Attached Total Frequency
Earlobe Genotype Number AA Aa aa Frequency
Hardy-Weinberg Equation p 2 + 2 pq + q 2 = 1 p+q=1
Q 1: Can an individual cuttlefish change its color to match its environmental background?
Q 2: Can an individual rock pocket mouse change its color to match its environmental background? Photo: Hopi Hoekstra Nachman, Hoekstra, D’Agostino 2003 PNAS
Genotype Frequencies in Six Locations Xmas Tule O’Neill Pinacate East Pinacate Mid Pinacate West Photos: Hopi Hoekstra
Selection against mismatching Photos by Hopi Hoekstra
Human Evolution? What effect would the following mutations have on human evolution: • a deleterious gene whose effect appears after 40 years of age? • a gene that shortens reproductive age from 13 to 5? • a gene that makes people more cold tolerant? • a gene that causes age-related death by 12 yrs?
Human Evolution? How might a gene lethal to children persist in a population? If a small group of humans scatters and disperses widely on an uninhabited land mass-would you expect their diversity to increase, decrease, or remain the same? What effects do antibiotics and pesticides have on the evolution of their target organisms? What trends have already occurred in human evolution?
Assessment Preclass: Readiness assessment test, misconception survey Formative: Student response to directed questions e. g. , clickers, one minute paper, student reporting during class Summative: Student assessment survey (SALG) Repeat misconception survey Exam questions