Small scattered fragments do not a dwarf make: biological and archaeological data indicate that prehistoric inhabitants of Palau were normal sized

Abstract

Current archaeological evidence from Palau in western Micronesia indicates that the archipelago was settled around 3000-3300 BP by normal sized populations; contrary to recent claims, they did not succumb to insular dwarfism.

Background: Previous and ongoing archaeological research of both human burial and occupation sites throughout the Palauan archipelago during the last 50 years has produced a robust data set to test hypotheses regarding initial colonization and subsequent adaptations over the past three millennia.

Principal findings: Close examination of human burials at the early (ca. 3000 BP) and stratified site of Chelechol ra Orrak indicates that these were normal sized individuals. This is contrary to the recent claim of contemporaneous "small-bodied" individuals found at two cave sites by Berger et al. (2008). As we argue, their analyses are flawed on a number of different analytical levels. First, their sample size is too small and fragmentary to adequately address the variation inherent in modern humans within and outside of Palau. Second, the size and stature of all other prehistoric (both older and contemporaneous) skeletal assemblages found in Palau fall within the normal parameters of modern human variation in the region, indicating this was not a case of insular dwarfism or a separate migratory group. Third, measurements taken on several skeletal elements by Berger et al. may appear to be from smaller-bodied individuals, but the sizes of these people compares well with samples from Chelechol ra Orrak. Last, archaeological, linguistic, and historical evidence demonstrates a great deal of cultural continuity in Palau through time as expected if the same population was inhabiting the archipelago.

Conclusions: Prehistoric Palauan populations were normal sized and exhibit traits that fall within the normal variation for Homo sapiens-they do not support the claims by Berger et al. (2008) that there were smaller-bodied populations living in Palau or that insular dwarfism took place such as may be the case for Homo floresiensis.

Figure 1. Map of the western Pacific (A) with inset of Palauan archipelago (B) (site names referred to in text are boxed).

Figure 2. Map of Chelechol ra Orrak (B:IR-1:23).

Figure 3. One of several human skulls found in unit E3/S1 at Chelechol ra Orrak in 2007 (depth = approximately 85–90 cmbs); all are normal sized (photo by SM Fitzpatrick).

Figure 4. 3D scatterplot of Orrak cranial measurements compared to other Micronesian male samples.

Note small minimum frontal breadth for Orrak D [Comparative data from 10], .

Figure 5. 3D scatterplot of Orrak cranium D compared to western Pacific and oceanic male samples.

Maximum cranial breadth, maximum length and basion-bregma height produce a good overall view of cranial size and show that Orrak D is large [Comparative data from 10], , .