ABSTRACT
Various types of size change have been observed in many Quaternary lineages. For instance, the dirk-toothed cats tended to grow larger throughout the Pleistocene, while the cheetah and raccoon-dog tended to become smaller. An excellent example of size change in the animal as a whole against an absolute time scale is given by Heintz & Garutt. These authors compared the skeletons of radiocarbon dated mammoth carcasses preserved in the permafrost of Siberia. The history of the brown bear in Europe shows size oscillation in relation to the alternation between glacials and interglacials. The brown bear population of Asia must have had an entirely different history; the form now inhabiting northeastern Asia is almost as large as the largest Pleistocene brown bears in Europe. While information on size and size changes in evolving lineages is easy enough to obtain – in principle at least – measurement of the standing population at any time is difficult.
