| molecular systematics of african 20-chromosome toads (anura: bufonidae). | intrageneric lineages and the historical biogeography of toads, genus bufo, are poorly resolved due to their conservative morphology, their highly conserved karyotypes (typically 2n = 22), and erratic patterns of interspecific hybridisation. here, we use mitochondrial and nuclear dna sequence data to reconstruct relationships of the 20-chromosome toads, a major component of the african bufonid fauna. mitochondrial 12s and 16s sequences from 29 species revealed two independent transitions between ... | 2004 | 15288046 |