Transcript Are Humans Evolving (PowerPoint) Madison 2004

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
p2 + 2pq + q2 = 1
p+q=1
Q1: Can an individual cuttlefish change its color to match its
environmental background?
Q2: 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