In this chapter, affinities of Aborigines viewed from dental characteristics will be discussed. As already mentioned, an extent of affinity of this population is different from character to character so that it is rather difficult to find a uniform conclusion which is compatible with all or most of the data presented in this paper.

Comparison of the mesiodistal crown diameters shows that Aborigines appear to represent the largest teeth among the populations compared in the present study. However, Pimas have also large teeth which are almost comparable with or, in some teeth, even exceed those of Aborigines. In this connection, it can hardly be concluded that the Aboriginal dentition is extraordinarily larger than that in any other modern populations. But it is still true that the former is much larger than the dentition in Caucasians and most of the Mongoloid populations. Difference between Aborigines and American Negroes is relatively small.

Shovel trait is most remarkable in Mongoloid populations, intermediate in Aborigines and much less in Caucasians and American Negroes. This likely shows that Aborigines are largely different from both Mongoloids and Caucasian-American Negro group in regard to this character.

Mahalanobis' generalized distances show that Aborigines are relatively close to Pimas and American Negroes, and far from the northern populations such as Ainu, Aleuts and Norwegian Lapps, Japanese and Caucasians being in between. The results seem to stress that Aborigines show less affinity to the northern people. In addition, a close affinity between Aborigines and Pimas as well as American Negroes is probably related to similarity in overall tooth size among these populations.

Quite interestingly, Penrose's shape distances show a close affinity between Aborigines and Caucasians, and again much less affinity between the former and the northern populations. If a view stressed by several previous authors that the shape component is much more important in the taxonomic problems can be adopted, special attention should be paid to the results obtained from the shape distance. In this regard, the following opinion expressed by Abbie (1969) might be of special importance: "It is quite logical, on our present knowledge at least, to class the Aborigines as proto-Caucasoids" (p. 219). A close affinity between Aborigines and Caucasians is also proved by the similarity in pattern of between-sex difference described in Section 4.2 of the present paper.

As to the frequency distributions of some non-metric characters, Aborigines are very close to the Mongoloids and far from Caucasians and American Negroes as shown by the Smith's distance coefficients. It should be noted that most of the non-metric characters compared are those considered to be of archaic origin in the course of human evolution, with only exception of the Carabelli's cusp. In this connection, Aborigines seem to share the archaic dental characters in common with the Mongoloids to a considerably large extent.

As mentioned above, the affinities of dental traits in Aborigines can hardly be concluded in a simple form, because they are largely different from character to character. However, perhaps one fact which may be safely concluded is that Aborigines show a larger extent of archaic dental characters in almost every respect of the present study. At the same time, it should be also pointed out that the extent of retention of archaic dental characters in Aborigines might not be so largely different from those of some other populations such as Eskimos and Pimas.

In addition, it seems to be of great importance that Aborigines are largely different from the northern populations in either Mahalanobis' distance or Penrose's shape distance. This evidently proves that these populations are different from each other in absolute size as well as in size proportions of the dentition.

Finally, the relationship between Aborigines and Ainu should be mentioned here on the basis of the results obtained from the dental characters. A close affinity between the two populations has been stressed since de Saint-Martin (1872) and later authors such as Anutschin (1876-1907), Debetz (1947, 1951), Levin (1958), etc. (see Kodama, 1970).

On the contrary, Yamaguchi (1967) and Omoto (1972) opposed this view based on the skeletal characteristics and biochemical polymorphisms of enzymes and proteins. Further, they emphasize a close affinity of the Aniu to the Mongoloid stock, especially to the Japanese living in the mainland of Japan. The same results also have been obtained by Kimura (1962) on the basis of finger and palm print patterns and by the present author based on non-metric dental characters (Hanihara, 1968, 1970; Hanihara et al., 1975).

As we have recognized already, the present study reveals the same trend, namely, Ainu are very distant from Aborigines and very close to ordinary Japanese in almost every character studied such as absolute crown size, Mahalanobis' generalized distance, Penrose's shape distance, and Smith's distance. Perhaps the only trait that shows a close affinity between Aborigines and Ainu is the shovelling trait in the maxillary central incisors. However, in general, the present study also supports the recent investigations mentioned above.