Relationships among frogs of the genera Alytes, Bombina, Discoglossus, and Baleaphryne were studied using the quantitative immunological micro-complement fixation technique. Albumins were compared among these genera as well as among several species of each genus. Our results indicate that the closest genetic relative of Baleaphryne muletensis is Alytes obstetricians. Moreover, the albumins of Baleaphryne and A. obstetricians are as similar or more similar to each other than the albumins of all four species of Bom bina, both species of Discoglossus, or the two species of Alytes available for study are to each other. We conclude that Baleaphryne is congeneric with Alytes. The distances measured among Alytes, Bombina, and Discoglossus suggest a Cretaceous (85-92 MYBP) divergence of Alytes from the lineage that later gave rise to Bombina and Discoglossus. These latter two genera appear to have diverged in the late Cretaceous, roughly 69-75 MYBP. Extant species of Bombina began diverging in the mid- to late-Miocene, as did Alytes obstetricans and A. cistemasii.
Discoglossus pictus and D. sardus in Europe last shared a common gene pool in the Pliocene. Albumins of individuals of D. pictus from Spain compared with northwestern African D. pictus suggest that these populations have been separated for some 9-10 million years, and are probably not conspecific. Our findings do not support Lanza et al.’s (1975, 1976) suggestions that Bombina and Alytes belong in the separate family Bombinidae.
Two species of gastric-brooding frogs, Rheobatrachus silus and R. vitellinus, currently constitute the subfamily Rheobatrachinae of the Australian leptodactyloid family Myobatrachidae. The relationships of Rheobatrachus to other myobatrachids have remained obscure due to the specializations for aquatic life and unique gastric-brooding behavior of Rheobatrachus and to the rare and endangered status of R. silus, until recently the only known species. An antiserum to the serum albumin of R. vitellinus was used in micro-complement fixation analyses comparing R. vitellinus to R. silus, and to representatives of most of the myobatrachid genera as well as to select representatives of the South American and South African leptodactyloid fauna. The two species of Rheobatrachus are each others closest relative and no other lineage is distinctly associated with these two species. Albumin comparisons involving other leptodactyloids show that Rheobatrachus is part of the Australian fauna, but as all of the major lineages appear to have arisen in the late Cretaceous, no single sister lineage to Rheobatrachus can be unambiguously identified.
Relationships among representatives of five genera of lacertid lizards from Iberia, Morocco, and South Africa were studied using quantitative micro-complement fixation analysis of serum albumin evolution. Using the albumin molecular clock to establish divergence times we suggest (1) South African Ichnotropis and North African Psammodromus diverged from the lineage representing Lacerta lepida-L. monticola during the Oligocene, (2) South African Pedioplanis and Heliobolus diverged from this lineage during the late Miocene, and (3) ancestral representatives of L. andreanszkyi, L. perspicillata and Podarcis hispanica diverged from lineages leading to L. monticola and L. lepida during the mid-Miocene. Radiation within the Palearctic Lacertidae has clearly been extensive, yet fewer than twenty percent of the species in this radiation have been examined biochemically. Until additional data can be gathered, the current classification of the Palearctic Lacertidae cannot be much improved and we recommend adherence to the taxonomy proposed by Arnold (1973).