Natural Selection
Natural Selection and Heritability:
From Butterflies to humans
Created for SPICE by Amy Non and Carmella O’Steen
March 2007
Natural Selection Simulation
Lesson 2
(as modified from Robert Gendron’s “Simulating Natural Selection” for Introductory Biology Lab College Course, Indiana University of Pennsylvania)
Key Question(s): What is natural selection? How does natural selection change allele frequencies over time? Does natural selection work differently on large versus small populations? What is genetic drift?
Science Subject: Biology
Grade Level: 7th-8th grade
Science Concepts: Natural Selection, Evolution
Overall Time Estimate: 2 90 minute class periods
Learning Styles: Kinesthetic
Vocabulary: Natural Selection: The process by which organisms with more favorable traits in a particular environment are more likely to survive and reproduce than those with unfavorable traits. Because these traits are heritable, favorable traits become more common in the population over time.
Genetic Variation: Variation amongst the genomes of individuals within a population or between populations. For example, although all humans are members of one species, no two individuals have the exact same genetic code. Variation usually comes from random genetic mutations or migrations of new individuals into a population.
Heritability: The proportion of variation in a population that is attributed to genetic variation, and is therefore passed on genetically from parent to offspring.
Allele: any one of a number of versions of a gene at a given locus (position) on a chromosome. For example, one allele of a gene that controls petal color of flowers may encode red flowers while a different allele of the gene may encode white flowers.
Genetic Drift: the tendency of any allele to vary randomly in frequency over time due to statistical variation alone. Genetic drift has more of an impact on allele
From Butterflies to humans
Created for SPICE by Amy Non and Carmella O’Steen
March 2007
Natural Selection Simulation
Lesson 2
(as modified from Robert Gendron’s “Simulating Natural Selection” for Introductory Biology Lab College Course, Indiana University of Pennsylvania)
Key Question(s): What is natural selection? How does natural selection change allele frequencies over time? Does natural selection work differently on large versus small populations? What is genetic drift?
Science Subject: Biology
Grade Level: 7th-8th grade
Science Concepts: Natural Selection, Evolution
Overall Time Estimate: 2 90 minute class periods
Learning Styles: Kinesthetic
Vocabulary: Natural Selection: The process by which organisms with more favorable traits in a particular environment are more likely to survive and reproduce than those with unfavorable traits. Because these traits are heritable, favorable traits become more common in the population over time.
Genetic Variation: Variation amongst the genomes of individuals within a population or between populations. For example, although all humans are members of one species, no two individuals have the exact same genetic code. Variation usually comes from random genetic mutations or migrations of new individuals into a population.
Heritability: The proportion of variation in a population that is attributed to genetic variation, and is therefore passed on genetically from parent to offspring.
Allele: any one of a number of versions of a gene at a given locus (position) on a chromosome. For example, one allele of a gene that controls petal color of flowers may encode red flowers while a different allele of the gene may encode white flowers.
Genetic Drift: the tendency of any allele to vary randomly in frequency over time due to statistical variation alone. Genetic drift has more of an impact on allele
References: Boaz N.T. and A.J. Almquist. 1997. Biological Anthropology: A synthetic approach to human evolution. Upper Saddle River: Prentice Hall.