Island Evolution

INTRODUCTION

How precious is hindsight? As the first human explorers left the confines of the continents and their homelands they had no inkling of the biological treasure houses of the hitherto uninhabited islands they set foot on, or the zoological curiosities, then extant but many now lamentably extinct due to man's ignorance of the miracle of evolution. That is until the young Charles Darwin set foot on the Galapagos Islands in 1834, making and collecting material for his formative work, 'On the Origin of Species' helped make us as humans conscious of the biological processes we now call speciation and evolution.

One island form, the iconic dodo, a flightless pigeon exterminated around 1685 on the island of Mauritius, now symbolises all that is now lost to present and future generations of the unique and fascinating life forms that have evolved as a result of small populations of organisms being isolated from the slower, and more discrete processes taking place on the mainland, which though subject to the same ecological laws as their island counterparts, are more discrete.

But for the discoveries of Charles Darwin in the Galapagos and his contemporary Alfred Russell Wallace in the Malay Archipelago, it may well have taken a lot longer for the process of evolution through natural selection to be identified. The fact that both scientists did their most significant work on island archipelagos shows that the process of speciation and evolution comes into prominence on islands and that these processes are illustrated by several interesting and unique patterns of speciation that highlight and explain the process of evolution through the production of many wonderful and unique life forms whilst indicating the ancestral form of the species, as well as its point of origin, also follows fascinating but immutable patterns of phenotypic form which demonstrate the mechanism of speciation.

The laws of evolution follow patterns. These patterns are patterns of speciation that are subject to the ecological laws of small gene pools and their collection of dominant and recessive characteristics which are exposed to new and challenging environments on which the ecological processes of adaptation are able to act relatively undisturbed from the ecological processes which their mainland counterparts are subject to. The results of these natural laboratory experiments produce characteristics which are not only uniquely characteristic of island forms but which at the same time demonstrate the processes of adaptation and survival which are contained within the gene pool of the species in question.

The purpose of this book is to illustrate and explain to the reader the nature of these processes. It is intended that this book will demonstrate the uniqueness of islands as natural evolutionary laboratories in which scientific experiments of ecology, evolution and alas through their fragility, all too frequently now extinctions are still taking place.

Nevertheless the processes of isolating and evolving gene pools enables the reader to understand also predict the processes taking place. It is also hoped that this book will also highlight the fragility and uniqueness of island speciation and an awareness of what remains is conserved and nurtured for future generations, who will hopefully learn not to repeat the mistakes of the past.