Table 2 Types of EE
Experiment typeGoal(s)Design featuresOutput
Artificial selection(i) Genetic architecture of specific trait(s), (ii) domesticationExperimenter defines fitness as a function of the value of the trait(s) of interestResponse to selection of the trait of interest; indirect responses of correlated traits
Laboratory natural selection(i) Evolution of genetic systems, (ii) genetic architecture of the response to natural selection on fitness in a defined contextExperimenter imposes selective milieu; nature decides what the relevant traits areThe multivariate phenotype, genome-wide allele frequencies in SNPs, CNVs, etc.
Competition experiments(i) Fitness of specific genotypes in a defined context, (ii) find the loci of adaptationExperimenter defines starting frequencies of different identifiable genotypes, perhaps associated with phenotypes; nature selects among themDerived allele (or genotype) frequencies, associated with phenotype frequencies
Reverse evolutionTest for nonadditive gene interactions: (i) Compensation of mutationally-degraded genotypes, (ii) natural selection erases historyEvolved population allowed to re-evolve under ancestral conditionsSome measure of phenotype or fitness
Invasion experiments(i) Test for transitions in character state, (ii) measure genetic drift independently of selectionRare genotypes introduced into a population; Highly replicatedProportion of invasions that go extinct are observed
Inbreeding experimentsDominance and epistasis as revealed by inbreeding and outbreeding depressionInbred individuals (typically offspring of self-mating or sib-mating) are compared to outcrossed individualsSome measure of phenotype or fitness, lineage survival during inbreeding
Mutation accumulationRate, spectrum, and distribution of mutational effectsReplicate populations derived from a known ancestor are maintained under minimal selectionSome measure of phenotype or fitness; molecular mutations measured by sequencing