Introduction

Abstract

Perhaps fascinated by the diversity of living organisms, humans have always been curious about the origin of this diversity. Mayr (1982a) traced the history of evolutionary thinking to suggest that “one must make a distinction between the acceptance of evolution and the adoption of a particular theory explaining its mechanism”. Whereas Lamarck’s (1809) Philosophie Zoologigue perhaps signified the first step toward accepting evolution, it was Darwin’s (1859) Origin of Species which provided the scholarly and persuasive thesis for gradual evolution and speciation under natural selection. The gradual improvements in geological and biosystematic records on one hand, and numerous detailed studies of variation within species on the other, have made Darwinism a powerful scientific theory. Dobzhansky (1973) made the often-cited statement: “nothing in biology makes sense except in the light of evolution”. However, although paleontologists described the evolution of species on the basis of fossil records, and although we have a lot of information on the factors of evolution, this does not at all mean that we understand evolution down to the smallest detail. Because of the complexity and multiplicity of interacting factors, particularly in the areas of population genetics and ecology as treated in this Volume, many open questions still remain to be answered.