Malecot's method of coancestry
Malecot's coancestry coefficient, formula_1, refers to an indirect measure of genetic similarity of two individuals which was initially devised by the French mathematician Gustave Malécot. formula_1 is defined as the probability that any two alleles, sampled at random (one from each individual), are identical copies of an ancestral allele. In species with well-known lineages (such as domesticated crops), formula_1 can be calculated by examining detailed pedigree records. Modernly, formula_1 can be estimated using genetic marker data. Evolution of inbreeding coefficient in finite size populations. In a finite size population, after some generations, all  individuals will have a common ancestor : formula_5. Consider a non-sexual population of fixed size formula_6, and call formula_7 the inbreeding coefficient of generation formula_8. Here, formula_1 means the probability that two individuals picked at random will have a common ancestor. At each generation, each individual produces a large number formula_10 of descendants, from the pool of which formula_6 individual will be chosen at random to form the new generation. At generation formula_12, the probability that two individuals have a common ancestor is "they have a common parent" OR "they descend from two distinct individuals which have a common ancestor  : What is the source of the above formula? Is it in a later paper than the 1948 Reference." This is a recurrence relation easily solved. Considering the worst case where at generation zero, no two individuals have a common ancestor, The scale of the fixation time (average number of generation it takes to homogenize the population) is therefore This computation trivially extends to the inbreeding coefficients of alleles in a sexual population by changing formula_6 to formula_19 (the number of gametes).