Age: THE black-footed rock wallaby. The northern hairy-nosed wombat. Gilbert’s potoroo. What is the common link between these animals? All are endangered Australian marsupials and all suffer from a lack of genetic variation. It is this lack of variation that is contributing to their potential extinction. A genetically "healthy" population is defined as having a large amount of genetic variability. The information for each of an organism’s characteristics is carried on a …