The study of biological distance is a way to measure the divergence of populations based on polygenic traits (Buikstra et al. 1990).  Variations in bone morphology may reflect genetic relatedness between populations.  Individuals or populations that are more similar in bone morphology are considered to have a relatively closer affinity, so biodistance studies can be useful in reconstructing population history and structure (Buikstra et al. 1990).  Furthermore, multiple scholars suggest that through biodistance studies, patterns of gene flow, population origins, and long-distance migration may be examined (e.g. Larsen 2015; Relethford and Blangero 1990; Stojanowski and Schillaci 2006). 

Various publications and databases are now available for researchers to access.  The W. W. Howells’ World Craniometric Data Set is one of the most popular databases for craniometric related studies.  However, in the previous work by the author, the identity of the crania from Philippines might be questioned.  It is hypothesized that the specimens from the Philippines in Howells’ data set may be admixture with the Han-Chinese people.  Since the well-known hypotheses suggest that there was intensive movement between Taiwan and Philippines (e.g., Bellwood 1988; Diamond 2000; Solheim 1988), the validity of the data would thus be crucial.  Therefore, one purpose of this study is to present a brief examination of the data of the Philippines in Howells' data set.

An estimation of biodistance from both cranial measurements and non-metric cranial traits between a series of crania of the early Han-Chinese people from Taiwan and specimens from the Philippines in Howells’ data were made.  On the other hand, data acquire from archaeological discoveries are also included in this research.  Comparisons with a few groups of Taiwanese Indigenous and areas around the island were included in order to provide a clearer picture of this issue as well as a further understanding of the biological affinity of different groups.