It has been known for long, and is a generally accepted fact now, that mutations with major (deleterious) fitness effects are almost always recessive. In the simplest case of two alleles, A and a, at a locus, the fitness of the three possible genotypes, AA, Aa, and aa, are usually denoted by 1,1 — hs, 1 — s. Here, s is the selection coefficient and h the dominance coefficient. A mutant is neutral if s = 0 and lethal if s = 1. If h = 0, then A is dominant and a is recessive; if h = 1, then a is dominant and A recessive; if h = V, one says there is no dominance; if 0< h <1, one speaks of intermediate dominance or codominance; if h <0, then there is overdominance, whereas underdominance prevails if h > 1.
Was this article helpful?
Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.