Inclusive Fitness Framework
Evolution through gene's eye thinking
The inclusive fitness framework explains how evolution occurs through the lens of gene's eye thinking. This framework, developed by William D. Hamilton, posits that natural selection favors characteristics that cause an organism's genes to be passed on, regardless of whether the organism produces offspring directly.
- Inclusive fitness is the sum of an individual's own reproductive success and the effects of its actions on the reproductive success of its genetic relatives.
- Genes producing effects that increase their own replicative success will replace other genes, producing evolution over time.
- Adaptations are selected and evolve because they promote inclusive fitness.
- Calculating Inclusive FitnessCalculate the inclusive fitness of an individual by summing its own reproductive success and the effects of its actions on the reproductive success of its genetic relatives.Pro tipUse the formula: inclusive fitness = classical fitness + effects on relativesWarningMake sure to weight the effects on relatives by the appropriate degree of genetic relatedness.
- Identifying Genetic RelativesIdentify the genetic relatives of an individual and calculate the degree of genetic relatedness.Pro tipUse genetic data or pedigree information to determine relatedness.WarningMake sure to account for multiple generations and complex relationships.
- Evaluating AdaptationsEvaluate the adaptations of an individual and determine whether they promote inclusive fitness.Pro tipUse the principles of inclusive fitness to guide the evaluation.WarningMake sure to consider the effects on both the individual and its genetic relatives.
Altruism in humans can be explained by the inclusive fitness framework, where individuals sacrifice their own reproductive success to help their genetic relatives.
Kin selection in animals can be explained by the inclusive fitness framework, where individuals prioritize the survival and reproduction of their genetic relatives.
The concept of inclusive fitness was first proposed by William D. Hamilton in the 1960s as a revision of classical fitness theory.