Evolutionary Analysis Flashcards
adaptation
A trait that increases the ability of an individual to survive or reproduce compared with individuals without the trait.
adaptive radiation
The divergence of a clade into populations adapted to many different ecological niches.
adaptive trait
A trait that increases the fitness of its bearer.
additive effect
The contribution an allele makes to the phenotype that is independent of the identity of the other alleles at the same or different loci.
additive genetic variation
Differences among individuals in a population that are due to the additive effects of genes.
agent of selection
Any factor that causes individuals with certain phenotypes to have, on average, higher fitness than individuals with other phenotypes.
alleles
Variant forms of a gene, or variant nucleotide sequences at a particular locus.
allopatric model
The hypothesis that speciation occurs when populations become geographically isolated and diverge because selection and drift act on them independently.
allopatry
Living in different geographic areas.
allozymes
Distinct forms of an enzyme, encoded by different alleles at the same locus.
altruism
Behavior that decreases the fitness of the actor and increases the fitness of the recipient.
anagenesis
Descent with modification but no speciation.
ancestral
Describes a trait that was possessed by the common ancestor of the species on a branch of an evolutionary tree.
antibiotic
A chemical, typically extracted from a microorganism, that kills bacteria by disrupting a particular biochemical process.
antigenic site
A portion of a protein that is recognized by the immune system and initiates a response.
assortative mating
Occurs when individuals tend to mate with other individuals with the same genotype or phenotype.
average excess
The average excess for allele a is the difference between the mean fitness of individuals carrying allele a and the mean fitness of the entire population. If the average excess for an allele is positive, then the allele will rise in frequency.
back mutation
A mutation that reverses the effect of a previous mutation; typically a mutation that restores function after a loss-of-function mutation.
background extinction
Extinctions that are not part of mass extinction events; thought to be due to typical types and rates of environmental change or species interactions as opposed to the extraordinary environmental changes that occur during mass extinctions.
Bateman gradient
The slope of the best-fit line relating reproductive success to mating success. Measures the strength of sexual selection.
Bayesian Markov Chain Monte Carlo
An approach to phylogeny inference based on computing the probability that a particular tree is correct, given a specific model of evolution for the characters being analyzed and the data observed.
