The straits that separate the Lesser Sundas from Bali and Java are deep, and powerful ocean currents run through them: so significant is this barrier that it has contributed to the development of what is termed the Wallace Line, a biogeographical boundary that divides the floras and faunas of Australasia in the south from the Asian ecosystems to the north. Currents might be more favourable if one approached from the north-east, through Borneo and the island of Sulawesi, and intriguingly, recent findings indicate archaic hominid settlement there reaching back over a million years. Even the approach to Sulawesi itself, however,...