Philip Houghton

The adaptive significance of Polynesian body form

The Polynesian people who settled a wide area of the tropical Pacific have a large and muscular body phenotype that appears to contradict the classical biological rules of Bergmann and Allen. However, a scrutiny of the conditions actually experienced by these canoe voyagers and small-island dwellers suggests that in reality the oceanic environment is labile and frequently very cold, and from it tribal technology offered little protection. The Polynesian phenotype is considered to be appropriate to, and have undergone selection for, this oceanic environment.

The mean measure of divergence and the use of non-metric data in the estimation of biological distances

Abstract The mean measure of divergence as a means of comparing two populations on the basis of non-metric data is described. Some statistical properties of this measure are derived and it is shown that its variance has frequently been misquoted in the literature. Alternative means of comparing two populations are presented and some improvements to the measure of divergence are suggested.

Computer location of medial axes.

Abstract The medial axis transformation of a two-dimensional outline is described and its relevance to the analysis of skeletal form is explained. Some properties of medial axes are summarised and from these properties a method of automatic location of medial axes is developed. Based on this method an ALGOL program for the computer location of medial axes is presented and illustrated with an example on Polynesian mandibles.

Selective influences and morphological variation amongst PacificHomo sapiens

Abstract The large range of human morphological variation found in the Pacific is usually ascribed to settlement out of southeast Asia by several “waves” of people of differing physical form. However, a body heat balance analysis suggests that much of the observed variation in body form is a consequence of varying environments within the Pacific. Inland people on large islands maintained an appropriately smaller body form for their true tropical environment. An increasingly large and muscular body mirrors increasing involvement with the sea, because this maritime environment, with its frequent combination of wind and wet, was effectively the coldest of all global climates for neolithic peoples. Such adaptation, along with the processes of genetic drift in this region of large and small islands, sufficiently accounts for the great range of phenotypic variation.