QUANTIFICATION OF A GENETIC MESSAGE IN SELECTION

The genetic communication system includes the following components: th e parent, which represents the information source and which emits mess ages; the gametes, which are the messenger carriers; and the off sprin g, which results from the decoding of two of these messages and can, i n turn, become an information source. In a diploid species, a pair of heterozygous homologaus loci may emit two equally probable messages, t he quantity of genetic information (Q) produced being equivalent to: Q = log(2) 2 = 1 bit. For n independent pairs of heterozygous homologou s loci, Q = n.log(2) 2 = n bits. The evolution of Q is examined whenev er the parent is used in inbreeding or crossbreeding. In the case of i nbreeding, the initial Q is depleted as the loci become homozygous; fo r hybridization the evolution of Q is unpredictable. In the case of pa irs of linked heterozygous homologous loci, Q is represented by an equ ation similar to that used to describe entropy. The value of entropy i s lower when linkage between loci is tighter, the freedom of choice in selection is reduced.