In 1975, he and collaborators presented a mathematical formulation of population bottleneck effects and clarified the genetic meaning of bottleneck effects.
Though this particular species of microhylids experienced a severe population bottleneck effect in the past, its succeeding expansion has allowed its current population trend to remain stable.
First, they show a very small genetic variation, which is indicative of populations that have experienced a population bottleneck and then developed in isolation for a long period.
According to a popular theory, these traditions reduced the danger of inbreeding and resulting population bottleneck in small and isolated settlements.