The process of separation of homologous chromosomes is during meiosis is referred to as disjunction. gametogenesis is production of gametes and it occurs in sex cells. disjunction occur during anaphase of meoisis I and in humans it results in separation of homologous chromosomes into two sets each containing 23 chromosomes. these chromosomes will eventually move to the opposite poles of the cell.
It should be natural selection since there is no external influence implied. (like environment or genetic mutations.)
