A comparison of the peopling of Australia and America offers insights into the population history of our species that would otherwise remain submerged. We begin with the observation that the first Americans have been in America some 15 000 years and they still resemble the Mongoloids of north-eastern Asia. In marked contrast, the first Australians have been in Australia well over 30 000 years and they do not resemble any of the mainland or Indonesian populations of south-eastern Asia.

The scope of essential topics and relevant data necessary to the comparison of the populations of these geographically disparate areas is now so large that it is necessary to organize the main topics or themes, and to condense and synthesize them. It is not possible to review in detail even the many important studies that have shed new light on the essential problems since the publication of The Origin of Australians (Kirk & Thorne, 1976) and The First Americans (Laughlin & Harper, 1979).

In 1949 it was as important as it is today to consider Australians in a discussion of the American Indian (Birdsell, 1951). Typological analysis was then still in vogue and E. A. Hooton had encouraged the recognition of several diverse racial components in the analysis of American Indians (Howells, 1973a). Population genetics, particularly appropriate in blood group studies, rapidly displaced typological analyses (Boyd, 1939, 1950, 1951, 1963).