Evolution and low temperature

Abstract

For evolution to take place in a population of animals there must be genetic variability within that population and selection pressures (biotic or environmental) to act upon that variability. The variety of genetic material must be expressed in some preadaptive feature(s) of form, function or behaviour. There is little difficulty in the a posteriori acceptance of the importance of low environmental temperature as a selective agent which drives evolution, indeed this book is full of examples of adaptation to cold conditions in which such selection is implicit. However, selective pressure is only one part of the equation, genetic variability being the other. If low temperature acted directly to enhance variability, evolutionary processes could be stimulated.