Species in the genus Bothrops s. l. are extraordinarily variable in ecology and geography, compared with other genera in the subfamily Crotalinae. In contrast to the trend of splitting large and variable groups into smaller, more ecologically and phenotypically cohesive genera, the genus Bothrops has remained speciose. In addition, previous phylogenetic analyses have found Bothrops to be paraphyletic with respect to the genus Bothriopsis. Taxonomic arguments exist for synonymizing Bothriopsis with Bothrops, and for splitting Bothrops into smaller genera, but the greatest hindrance to taxonomic revision has been incomplete phylogenetic information. We present a phylogeny of Bothrops, Bothriopsis, and Bothrocophias based on 85 characters of morphology and 2343 bp of four mitochondrial gene regions, and with significantly greater taxonomic coverage than previous studies. The combined data provide improved support over independent datasets, and support the existence of discrete species groups within Bothrops. The monophyly and distinctness of these groups warrant recognition at the generic level, and we propose a new taxonomic arrangement to reflect these findings.

DolloÕs law, that complex characters are not regained in evolution, is a pattern applied to many systems. Recent work has evaluated unidirectional evolution in a number of contexts, and several violations of this law have been documented. These methods have also been criticized for potentially overestimating reversals. We test the hypothesis that the ancestral reproductive mode of oviparity can be regained in vipers, in opposition to DolloÕs law. We use model comparison and ancestral character state reconstruction methods that address recent criticisms, and find evidence both supporting and refuting DolloÕs predictions from different analyses. We discuss our results in the context of unidirectional evolution and review factors required for strong inference of violations of DolloÕs law.

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During routine parasitological surveillance and monitoring activities within a National Control Programme for control of human schistosomiasis in Uganda, it was noted that cattle grazing in a water meadow immediately adjacent to Tonya primary school, where the prevalence of intestinal schistosomiasis in children was in excess of 90%, were unusually emaciated. To test the hypothesis that there may have been an anthropozoonotic focus of Schistosoma mansoni within the local herd, a young female heifer, clearly emaciated and c. 8 months old, was slaughtered from which schistosome worms were later recovered by dissection. As female worms inspected by microscopy were not gravid, morphological identification proved inconclusive but analysis of cytochrome oxidase subunit I (COI) and small subunit (SSU) ribosomal DNA sequences from these worms identified them as Schistosoma bovis Sonsino, 1876. This is the first substantiated report of S. bovis from Lake Albert, western Uganda. Further epidemiological surveys are needed to clarify the extent of bovine schistosomiasis within this region, particularly so since this lakeside plain has been earmarked as a future game reserve.