Polyploidy and Distribution

Abstract

Since Polyploidy has been recognized as a widespread and common phenomenon among eukaryotes, particularly higher plants, biologists have been interested in possible causal connections between Polyploidy and distribution, and have tried to present relevant generalizations and “rules.” A quick historical survey of this topic takes us back to the first relevant studies on angiosperms during the thirties: Hagerup (1) and Tischler (2) demonstrated a frequency increase of polyploids from southern to northern latitudes and interpreted it as the result of greater hardiness of polyploids under extreme ecological conditions. Mantón (3), on the basis of her studies on Biscutella in glaciated and unglaciated areas in Europe, was the first to stress the better colonizing potential of polyploids. The further elaboration of this question in the forties and fifties can be exemplified by contributions from A. and D. Löve (4,5), Stebbins (6,7), and many others. During the same time studies concerned with Polyploidy and distribution were extended to some animal and other plant groups (cf. contributions in this Conference), foremost to the pteridophytes, again by Mantón (8). Her finding of very high chromosome base numbers in many fern plants paved the way to our understanding of paleoPolyploidy, a phenomenon to which publications by Favarger (9) and S. and G. Mangenot (10) have further contributed during the sixties.