A note on the northern “drifts” in the Malay Peninsula. Records of the Raffles Museum, No. 14
F.N. Chasen’s brief note responds to questions posed by Sir Richard Winstedt regarding prehistoric human movements in South-East Asia, offering a zoo-geographical perspective on the diffusion of animal faunas as an analogue for human migration routes (p. 99).
Summary
Chasen addresses two of Winstedt’s questions. First, regarding whether slab-grave builders sailed from Indo-China to the Sunda Straits and back to Perak, Chasen argues that the present distribution of certain animals supports a movement through Borneo (or via past land connections west of that island) south to the Sunda shelf, after which the drift curled north-east, reaching islands off the west coast of Sumatra, North Sumatra, and possibly the Malay Peninsula. He identifies a second, purely continental influx from the north through the Peninsula, and notes that where these eastern and western drifts meet, closely related forms may coexist as distinct “species” maintained by physiological intolerance (p. 99).
Second, regarding why immigrants would settle at the far end of a trans-Peninsular route, Chasen observes that many Malaysian animal species are commonest at the extreme distal limit of their range, with a distributional gap between them and relatives nearer the point of invasion—a pattern he likens to wave-like advance rather than gradual infiltration (p. 100). He concludes by suggesting that the stimuli driving southern movements of men and their cultures may have been identical to those prompting the diffusion of larger mammals, and that routes and barriers may sometimes be correlated, as has been noted for Bornean peoples and the orang-utan (p. 100).