The Francolins constitute the largest genus in the Galliform family Phasianidae. There is little accord concerning the taxonomic classification of its members. In the past, information on this group has been provided by morphological and palaeontological evidence. An investigation into the molecular history of this group is presented, using mitochondrial DNA (mtDNA) as an evolutionary tool. A comparison of mtDNA restriction fragment lengths has been used to help define the phylogenetic relationships between 13 southern African Francolin species and a selected outgroup, the Japanese Quail. Both cladistic and distance-based analytical methods have been used to construct phylogenies from the molecular fragment data. The trees relating the Francolins are in general agreement with the traditional classification based on morphological, behavioural and morphometric studies, but differ in the branching order of two species, F. levaillantii and F. hartlaubi. A recent proposal for the partitioning of the genus into two monophyletic assemblages of quail-like "partridges" and pheasant-like "francolins" is supported by mtDNA fragment data, with the exception of the two aberrant taxa. On the basis of the initial fragment size comparison, F. hartlaubi and F. levaillantii constitute part of an unresolved quadrichotomy at the base of the tree. A restriction endonuclease site mapping approach has been utilized to provide a deeper resolution for the molecular phylogeny. Detailed mtDNA restriction endonuclease maps of F. levaillantii, F. hartlaubi, two species representing the "partridge" and "francolin" monophyletic groups respectively, and also of the Madagascar Partridge, have been constructed. Phylogenetic analysis of this data has helped to resolve the problematic placement of the two aberrant taxa by showing an early separation of F. levaillantii from the "partridge" lineage, and of F. hartlaubi from the "francolin" lineage. The Madagascar Partridge was anticipated to be a likely sister-taxon to the whole group, but instead appears to have close relationships within the "partridge" lineage.

A phylogenetic study of eleven cetaceans was undertaken using Restriction Endonuclease Maps (RSM) of mitochondrial DNA (mtDNA). One species from the suborder mysticeti (baleen whales) was sampled, and of the ten odontocetes (toothed whales) sampled two were from the family Ziphiidae (beaked whales) and eight were from the family Delphinidae (dolphins) (each representing a different genus). The primarily opportunistically obtained (i.e. from strandings or accidental death in commercial trawl nets) heart tissue generally yielded high quantities of mtDNA which is needed for double digest fragment analysis. The mtDNA extracted from the sampled taxa was cleaved with fifteen different six-base Restriction Enzymes (RE's). Using the three-way method of analysis and aided by the computer program Resolve (Ver. 2.7) (Harley, unpublished), RSM's were constructed. Distance (Neighbor-Joining and Fitsch-Margoliash) and cladistic (Maximum Parsimony and Bootstrap) methods were used to infer phylogenies. The baleen whale was used as an outgroup for the cladistic analysis. Both the distance and both the cladistic methods produced the same single topology, which is concordant with morphologically based classifications. The two differences (within the Delphinidae), viz. Grampus' most basally rooted position and Cephalorhynchus' grouping with the Delphininae are of taxa whose groupings are unresolved in the morphologically based classifications. Using Brown et al's (1979) molecular clock, very recent divergence times at the generic, family and suborder levels were obtained, when compared to fossil based estimates. Using the odontoceti/mysticeti split the base substitution rate of cetacean mtDNA was estimated to be much slower than that of terrestrial mammals (0,3% compared to 1,0% Myr⁻¹). A similarly slow rate was calculated for cetacean nuclear DNA (nDNA) (0,09% Myr⁻¹) (Schlotterer et al, 1991). It remains an unresolved issue as to whether the base substitution rate of cetacean DNA is slower than terrestrial mammals or whether the fossil evidence needs to be reinterpreted. The time of the mysticeti/odontoceti split is palaeontologically uncertain and the suggested monophyletic status of the extant suborders has been questioned, thus making the calculation of cetacean base substitution rate risky. Equally, the incomplete fossil record can lend itself to misinterpretation.