These studies usually involved the separate culture of individual ascospores resulting from a single meiotic event and determining the genotype of each spore.
An analysis of 939 asci in which the genotypes of all meiotic products (ascospores) could be determined found 11 asci with an exceptional segregation pattern.
They raise the question of why such individuals should risk shuffling their genes with those of another individual, as occurs during meiotic recombination?