: 11 The later definition by Cavalli-Sforza & Bodmer (1971) is currently used: Genetic polymorphism is the occurrence in the same population of two or more alleles at one locus, each with appreciable frequency, where the minimum frequency is typically taken as 1%.
The financial world splits up its calendar into four quarters, each three months long. If January to March is the first quarter, April to June is the second quarter, and so on, though a company's first quarter does not have to begin in January.
Answer: The terms first quarter and last quarter refer not to the moon's apparent shape but to the points in time within the lunar month. We recognize four main phases, and therefore divide the lunar cycle into 4 parts, or quarters. Starting with new moon, then first quarter, full, then last quarter, then back to new.