INCLUSIVE FITNESS Meaning and
Definition
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Inclusive fitness is a concept in evolutionary biology that measures an individual's success in passing on genetic material not only through direct reproduction but also through assisting relatives in their reproduction. It is a measure of an organism's overall reproductive success, taking into account both its own reproductive behavior and its impact on the reproductive success of its relatives.
Inclusive fitness theory was developed by British biologist W. D. Hamilton in the 1960s to explain the evolution of altruistic behavior. According to this theory, individuals can increase their inclusive fitness by engaging in behaviors that benefit their close relatives, even at a cost to their own direct reproductive success. This is because genetically related relatives share a proportion of an individual's genes, so by helping these relatives reproduce, an individual can indirectly pass on more of its own genes.
The concept of inclusive fitness is closely related to the theory of kin selection, which posits that natural selection can favor genes that promote altruistic behaviors towards genetically related individuals. By considering the genetic relatedness between individuals, inclusive fitness provides a framework for understanding the evolution of seemingly altruistic behaviors in the natural world.
Inclusive fitness can be quantified mathematically using Hamilton's rule, which states that an altruistic behavior can evolve if the benefits to the recipient multiplied by their genetic relatedness to the altruist exceed the costs to the altruist. This mathematical framework allows researchers to study and predict the conditions under which altruism may evolve in various species and social structures.
Etymology of INCLUSIVE FITNESS
The term "inclusive fitness" was coined by the evolutionary biologist William D. Hamilton in 1964. The etymology of "inclusive" comes from the Latin word "inclusivus", which means "including" or "comprising". "Fitness" in this context refers to the relative reproductive success and survival of an individual or gene in a population. Therefore, the term "inclusive fitness" refers to the reproductive success of an organism, not only through its own offspring but also through the reproductive success of related individuals who share some of its genes.
