Definition of "variation"
noun
usually uncountable, plural variations
The act of varying; a partial change in the form, position, state, or qualities of a thing.
Quotations
Plant breeding is always a numbers game. […] The wild species we use are rich in genetic variation, and individual plants are highly heterozygous and do not breed true. In addition, we are looking for rare alleles, so the more plants we try, the better.
2013 May-June, David Van Tassel, Lee DeHaan, “Wild Plants to the Rescue”, in American Scientist, volume 101, number 3