Darwinian fitness

biology

Also known as: adaptive value, evolutionary fitness, relative fitness, selective value(Show More)

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June 25, 2026

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Darwinian fitness, in biology, quantifies the relative probability that a hereditary characteristic will be reproduced. It is a measure of reproductive efficiency, indicating how successfully an organism with a particular trait passes its genes to the next generation.1

Natural selection favors traits that increase an organism's ability to survive and reproduce in its environment. Favorable variations are preserved and multiplied, leading to organisms that are well-adapted to their surroundings. This process can occur through differences in survival, fertility, development, or mating success, all of which affect the number of offspring an organism leaves. Fitness is crucial for understanding evolution, as it explains how beneficial traits become more common over time.12

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kin selection
…play when evaluating the genetic fitness of a given individual. It is based on the concept of inclusive fitness, which is made up of individual survival and reproduction (direct fitness) and any impact that an individual has on the survival and reproduction of relatives (indirect fitness). Kin selection occurs when…
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…play when evaluating the genetic fitness of a given individual. It is based on the concept of inclusive fitness, which is made up of individual survival and reproduction (direct fitness) and any impact that an individual has on the survival and reproduction of relatives (indirect fitness). Kin selection occurs when…
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reproduction
Natural selection and reproduction
…act continuously in successive generations, Darwin also recognized that the variations had to be inherited, although he failed to fathom the mechanism of heredity. Moreover, the amount of variation is particularly important. According to what has been called the principle of compromise, which itself has been shaped by natural selection,…
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…act continuously in successive generations, Darwin also recognized that the variations had to be inherited, although he failed to fathom the mechanism of heredity. Moreover, the amount of variation is particularly important. According to what has been called the principle of compromise, which itself has been shaped by natural selection,…
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reproductive behaviour
Displays
…to convey information about his relative fitness; that is, his ability, with respect to other displaying males, to maximize the survival of his genes into the next generation. Both the brightness of his coloration and the frequency with which he struts say something about the effectiveness of his genes to…
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…to convey information about his relative fitness; that is, his ability, with respect to other displaying males, to maximize the survival of his genes into the next generation. Both the brightness of his coloration and the frequency with which he struts say something about the effectiveness of his genes to…
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evolution
The concept of natural selection
…quantified by a measure called Darwinian fitness or relative fitness. Fitness in this sense is the relative probability that a hereditary characteristic will be reproduced; that is, the degree of fitness is a measure of the reproductive efficiency of the characteristic.
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…quantified by a measure called Darwinian fitness or relative fitness. Fitness in this sense is the relative probability that a hereditary characteristic will be reproduced; that is, the degree of fitness is a measure of the reproductive efficiency of the characteristic.
Read More