sporting of nature: the action on the part of nature of producing an anomalous form or variety; an instance or occasion of this. Obsolete.

The deviation of organisms, esp. plants, from the parent stock or type, esp. by spontaneous mutation; (also) an abnormal form or variation so…

Biology. A mutation, esp. one with marked effects on several characters.

Biology. A change of any magnitude in the genetic material of an organism, which may in certain cases be inherited by subsequent generations…

a mutation affecting only one nucleotide in a DNA sequence.

the tendency for recurrent mutation (rather than selection) to alter the frequency of a particular allele within a population, or more generally to…

A major genetic mutation, esp. as a postulated cause or significant contributory factor in the evolution of new taxa; a mutation which causes a…

Originally: mutation that has a small or inapparent effect on the phenotype; an instance of this. In later use also: a point mutation.

The production of genetic mutations.