Assortive mating in a population in which two alleles are segregating

Assortative mating for a metrical characteristic in Drosophila

“…The possibility of positive assortative mating developing along a dine has been discussed by O'Donald (1960) and Parsons (1962). A dine is in any case a form of disruptive selection, and may occur when different conditions of survival and reproduction occur at the opposite ends of the geographical range of a species.…”

“…There is suggestive evidence of positive assortative mating in a colour phase dine in the Arctic Skua (O'Donald, 1959). A more complete discussion of the likely effects of assortative mating in natural populations is given by O'Donald (1960) and Parsons (1962).…”

The initial increase of a new gene under positive assortative mating

“…Then c(u+v) of A phenotypes and w of a phenotypes will mate with like phenotypes. Of the A phenotypes, there will be three mating types showing assortative mating, namely AA xAA, AA xAa and Aa xAa which will occur in The above table without viabilities was given by O 'Donald (1960).…”

“…Mating preferences of various types have been described by Merrell (i4. ) and Rendel (i) The examination of equilibria attained under systems of mixed random mating and positive assortative mating has been carried out by O' Donald (1960) but he did not include parameters to take into account the selective values of the various genotypes. Inclusion of such parameters in the model will not permit a simple algebraic expression for the determination of the equilibrium positions and the conditions for their stability, but would require considerable computation.…”

A model of assortative mating with partial dominance

“…ONE of the standard models of assortative mating is that put forward by O'Donald (1960) in which one gene is dominant and a fraction of unions take place between like phenotypes and the remainder take place at random.…”