The number of offspring produced by an individual during its lifetime
Absolute fitness
Plastic
An allele that spreads because it is linked to another allele that is the target of selection
Hitchhiking
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Directional selection
ω
Relative fitness
Average fitness of individuals with a gene in a population
Allele fitness
A phenotype that develops the same way in every environment
canalized
Alleles that reach either 100% or 0% frequency in a population
fixation
When selection favors the average, causing trait variation to decrease across generations
Stabilizing selection
s
strength of selection
The reproductive output or survivability of one allele vs other alleles in a population
Relative fitness
Pigmentation increases when organisms develop with more sun and decreases when predators are present
plastic
Two genes next to each other on a chromosome
genetic linkage
Selection when humans are the selective force
artificial selection
W
absolute fitness
A reason that may prevent a beneficial mutation from becoming fixed
Drift/linkage disequilibrium
Fruit flys develop round wings in the presence of arsenic and in the presence of predators
canalization
When two traits are correlated for any reason, but often share some functional relationship
integration
Selection of a combination of multiple traits
Correlational selection
h^2
heritability
Often calculated as the survival rate of a given allele
strength of selection
The idea that plastic traits are often caused by some gene regulatory mechanism, that can change due to selection
When a change increases fitness of one trait, but decreases fitness of another
Evolutionary tradeoff
When selection favors the extremes of phenotypes driving higher variance and a bimodal distribution across generations
disruptive selection
Δz
Change in phenotype average