Adaptation to pesticides usually decreases relative fitness of organisms in the absence of pesticides.

However markers showing adaptive responses to environmental change can be 'non-neutral' (e.g. mutational changes affect their relative fitness within a population).

In population genetics, the selection coefficient is a measure of the relative fitness of a phenotype.

Microevolutionary variation does affect the relative fitness and transmission dynamics of antibiotic-resistant strains.

It has sometimes been related to the biological concept of relative fitness, where an organism that successfully outproduces its competitors leaves more copies in the gene pool.

The relative fitness of various traits will therefore vary between populations.

Their relative fitness is given by (cf. op.

There are two commonly used measures of fitness; absolute fitness and relative fitness.

Perhaps pleiotropic effects of the genes acting on colour also affect the beetle's physiology, and hence its relative fitness.

The candidates have serious differences over the scope of the Attorney General's job and their relative fitness for it.