Glossina and the Extinction of Tertiary Mammals

Abstract

DR. G. D. H. CARPENTER (NATURE, March 20, p. 46) asks why we should suppose that the occurrence of tsetse-flies (Glossina) in the Miocene of Colorado might have had anything to do with the extinction of some of the large Mammalia. He points out that such flies exist in Africa to-day, carrying trypanosomes, and the native Mammalia nevertheless survive and flourish. It is known, however, that in Miocene times there were extensive migrations of animals, from mammals to insects, and the New and Old Worlds each received important contributions from the other. In such periods of migration it is perfectly conceivable that Glossina might appear in a new region, carrying a trypanosome which would be highly pathogenic for certain elements of the resident fauna. Even in Africa we do not know what animals may be absent to-day owing to the former prevalence of disease-producing organisms.