The babirusa (Babyrousa babyrussa) is believed to be the most distinct pig genus in the world. For example, among a number of unique anatomical characteristics, it is the only mammal with vertically growing canine teeth. Endemic to Sulawesi, and found on a few neighbouring islands such as Buru, Mangole, Taliabu and the Togian islands, the babirusa has a very limited geographical distribution. The available evidence seems to indicate that this is because Sulawesi has long been isolated by water from mainland Asia; the strait between Sulawesi and Borneo was apparently never narrower than about 50 kilometres during Pleistocene times. The current hypothesis is that the Babyrousa developed along a separate evolutionary line since Oligocene times (Thenius, 1970). This concept is supported by analyses of chromosome banding patterns that indicate that the chromosomes of the babirusa differed from those of other wild pigs (see Bosma et al, 1991). However, more recent work using DNA probes have shown that there are closer similarities between the chromosomes of Sus and Babyrousa than previously thought (Thomsen et al, 1996). DNA studies are beginning to reveal detailed molecular information with regard to the nature of the relationships babirusa has with other extant pig species (Randi et al, 1995; Lowden et al, 2002). New genetic analyses can be expected to give a much better understanding of the origin of the babirusa
