| dc.description.abstract | H. m. broadleyi and H. m. verrucosus are not only different in terms of colour pattern, but distinct genetic differences were detected in restriction site maps of their ribosomal DNA. A sequence divergence value of 13,8% was found between the subspecies. This value exceeds the range recorded between separate species of the genus Rana, ie. 2,2 % between Rana pustulosa and Rana tarahumarae, and 10, 1 % between Rana pustulosa and Rana pipiens. The value of 13,8% between the subspecies is also in the same range as that found between was detected between samples from three different localities within the distribution range of H. m. verrucosus. The genetic data associated with the different colour patterns, suggests that H. m. broadleyi and H. m. verrucosus can be regarded as distinct species. However, a similar study should be performed to examine the genetic status of the subspecies forming the gradient along the east coast of southern Africa. Although the effect of concerted evolution (as discussed in Chapter 2) allows for small sample sizes it would be useful to examine a large number of individuals especially from the overlap zones to determine the extent of genetic heterozygosity and to determine if similar genetic differences (found between H. m. broadleyi and H. m. verrucosus) exist between the rest of the subspecies. The current study has shown that genetic evaluation of all the southern African H. marmoratus subspecies could have a positive impact on the taxonomy of this group of frogs which is still unresolved. This study has identified at least two species within the H. marmoratus complex and it is possible that more species exist within the group. Because of morphological homogeneity it will be difficult to use morphological characters, but more than one molecular technique can be utilized to verify results obtained with one technique. | en_US |
