Fluoroacetate Tolerance, a Genetic Marker in Some Australian Mammals.

Abstract

The toxin fluoroacetate occurs naturally in many southwestern Australian species of the legume genera Gastrolobium and Oxylobium. No fluoroacetate-bearing species are known from southeastern Australia. Herbivores have evolved a high level of genetic tolerance to this toxin; this has persisted in some mammalian herbivores whose range now extends beyond the range of the toxic plants. Other species of mammals have acquired tolerance since extending their range into south-western Australia. This tolerance can be used as a genetic marker to identify the geographic origin and trace the subsequent spread of herbivorous mammals in southern Australia. In this paper, this marker has been used to clarify the recent evolutionary history of the western grey kangaroo, the tammar wallaby and the bush rat.