MODELING PROBLEMS IN CONSERVATION GENETICS USING DROSOPHILA - CONSEQUENCES OF HAREMS .145.

Polygamous mating systems occur in most mammals and some birds. They a re predicted to reduce effective population sizes and to increase inbr eeding and loss of genetic variation. To evaluate this theory experime ntally, ten replicate lines of a Harem treatment with seven females an d one male and nine replicate lines of an equal sex ratio (ESR) treatm ent with four pairs of parents per generation were maintained for eigh t generations. Equalization of family sizes was used in both treatment s. Loss in average gene diversity was greater in harems than ESR (0.16 5 v 0.063), the effective population size lower (6.6 v 13.9), and the relative reproductive fitness lower (0.21 v 0.46). Harem mating struct ures should be avoided or circumvented wherever possible in the manage ment of captive populations