Patterns of Growth

Abstract

One of the major aims of evolutionary biologists is to explain the extraordinary diversity of life histories within and between species of animals and plants. This task assumes particular importance as it is through the life history that the benefits of adaptation will be expressed, and by measurement of survival and reproduction we can directly address the currency in which adaptation should be interpreted. For the purposes of this review, the life history of marsupials and other mammals can be usefully divided into two elements, development and reproduction. Development in turn contains several important elements, which unfortunately are often treated as synonymous, particularly by ecologists. These are differentiation, growth and maturation. These separate components are often tightly linked; for example, commencement of reproduction is often so closely synchronised with the cessation of growth that direct causation can be implied. However, the various aspects of development are properly treated as dissociable.