Fig. 8. Relationship of the human races. Distances between the centers of circles are indicative of the degree of similarity.
[Figure 8] attempts to represent graphically the degree of resemblance and difference between the principal physical types as they have been summarized in the table and preceding discussion; the genealogical tree in [figure 9] is an endeavor to suggest how these types may have diverged from one another in their development.
Fig. 9. Tentative family tree of the human races.
28. Continents and Oceans
One fact about the classification stands out clearly, namely, that the three grand races are not limited to particular continents. It is true that the center of gravity of the Caucasians is in or near Europe, that the biggest block of Negroids is situated in Africa, and the largest mass of Mongoloids in Asia. It is even possible that these three types evolved on these three continents. But each of them is inter-continental in its present distribution. Western Asia and northern Africa as well as Europe are Caucasian. There are Negroids in Oceania as well as in Africa, and the Mongoloids are found over Oceania, Asia, and both Americas.
In fact the distribution of the three primary races can better be described as oceanically marginal than as continental. The Caucasian parts of Europe, Asia, and Africa surround the Mediterranean Sea. The African and the Oceanic branches of the Negroid race are situated on the left and right sides of the Indian Ocean. The Mongoloid habitat in Oceania, in eastern Asia, and in North and South America almost encloses the Pacific Ocean. (Figs. [10] and [11].)