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 OutlineThree 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 Frequency

Free

Attached

Total

Earlobe Genotype

Number Frequency

AA

Aa

aa

Hardy-Weinberg Equation

p2 + 2pq + q2 = 1 p + q = 1

Q1: Can an individual cuttlefish change its color to match itsenvironmental background?

Photo: Hopi Hoekstra

Nachman, Hoekstra, D’Agostino 2003 PNAS

Q2: Can an individual rock pocket mouse change its color to match its environmental background?

Photos: Hopi Hoekstra

Genotype Frequencies in Six Locations

XmasTuleO’Neill

Pinacate EastPinacate MidPinacate West

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?

AssessmentPreclass: 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