Evo. Pop. Gen.
Worked with single gene traits in natural populations
Low population variability, low heterozygote frequency
Alternative alleles are harmful
Main evolutionary force- directional selection
Species variability given mainly by between-population variation
Examined the chromosomal polymorphisms in Drosophila populations
Natural populations are generally variable w/ high heterozygosity
Dominating force: Overdominant selection
Species variability given within-population variation
A trait that can be described as a category (Ex: black or red coat color, horned or polled, coat color dilution)
Example: Stem color of tobacco
Have 1 or 2 genes
Have few genotypes
Phenotypic categories
A characteristic controlled by multiple genes as well as the environment (Ex: IQ, blood pressure, height, and weight)
Example: Number of grains of wheat
Have many genes
Many genotypes
Continuous distribution of the phenotypes
Example of a qualitative trait
Involves two phenotypes: peppered (recessive), and carbonara (dominant)
Example of a quantitative trait
In small populations, evolutionary forces (ex: environmental changes) have a bigger effect, causing more drift and variation
Example of a quantitative trait
Each population was found to have its own phenotypic average, and its own variance (differences)