摘要
From the standpoint of evolution, caring for old parents may be maladaptive, because they have ceased reproduction, so that the benefit for inclusive fitness may not be expected. Then why do we care for old parents? In this study, the evolution of care for the elderly was examined, by using an evolutionary genetic model, in which pleiotropic constraints between behaviors expressed in different social contexts among family members were assumed. It was suggested that establishing a solid relationship with parents during infancy should be selectively favorable, even though old parents have to be cared for in the future, but that caring for old parents may be excluded from the population if this behavior imposes high costs on reproduction of the younger generation. Despite the diminishing numbers of individuals within the population, care for the elderly may not be readily selected against, but at the same time this may not contribute to the rate of increase in population size. The significance of discussing the behavior of elderly caring from the standpoint of evolutionary genetics was emphasized.
From the standpoint of evolution, caring for old parents may be maladaptive, because they have ceased reproduction, so that the benefit for inclusive fitness may not be expected. Then why do we care for old parents? In this study, the evolution of care for the elderly was examined, by using an evolutionary genetic model, in which pleiotropic constraints between behaviors expressed in different social contexts among family members were assumed. It was suggested that establishing a solid relationship with parents during infancy should be selectively favorable, even though old parents have to be cared for in the future, but that caring for old parents may be excluded from the population if this behavior imposes high costs on reproduction of the younger generation. Despite the diminishing numbers of individuals within the population, care for the elderly may not be readily selected against, but at the same time this may not contribute to the rate of increase in population size. The significance of discussing the behavior of elderly caring from the standpoint of evolutionary genetics was emphasized.