Ecological Genetics of the Wild Rabbit in Australia. III. Comparison of the Microgeographical Distribution of Alleles in Two Different Environments

Abstract

The differences in distribution of gene frequencies at three polymorphic loci (adenosine deaminase, carboxylesterase-1 and phosphogluconate dehydrogenase) were determined for rabbit populations living in two markedly different environments. One, a highland population from Snowy Plains N.S.W., has low productivity and high survival rates, and the second, a dry plains population from Urana, N.S.W., has high productivity and low survival rates. The amount of sub population differentiation at each locus was distinctive, and was different in the two environments with significant differentiation occurring for phosphogluconate dehydrogenase at both areas, for carboxylesterase-1 at Snowy Plains and for adenosine deaminase at Urana. The general significance of these results was demonstrated by determining the distribution of the variation in a third population. This population was subject to the same historical climatic events as the Urana population and showed a similar pattern of variation. Various explanations of the data are considered and a combination of chance and selection, rather than either alone, seems to offer the most satisfactory explanation. The demographic differences between the populations seemed to play no part in explaining the patterns observed.