The Land and Wild-life of Australasia [antikvár]

Preface To many biologists, Australasia—the Australian continent with its outlying islands—is the most interesting region in the world. Its flora and fauna are a bizarre mixture of the primitive and the advanced, and provide better glimpses into some of the basic processes of evolution than those of any other continental area. The insular nature of the whole region—the continent itself has been isolated for at least 60 million years—makes it possible for scientists to observe how one particular group, in this case the marsupials, has been allowed to radiate with a minimum of interference by outside influences; and how at the same time a continental fauna may be built up on an original population by a series of invasions and superimpositions, as in the case of Australia's birds. Because they impose something like laboratory conditions on a natural environment, islands have always been fascinating to evolutionists, from the time of Darwin and Wallace to the present day. Islands not only allow primitive types to survive, but they also have other, equally interesting effects. How do creatures get to them across the water ? Some fly—New Zealand has only two types of mammals, but both are bats which clearly arrived on the wing. Others "island hop"—and the Pacific islands in particular show just what groups have this ability and how they go about it. And what happens after a species reaches an island ? What it finds may well be an unbalanced nature—i.e., opportunities for life which have gone unexploited simply because other animals had not succeeded in reaching the islands to exploit them. So the new arrivals proceed to fill these vacant niches by diversifying in some cases into ways of life which elsewhere they do not follow at all: that is how New Zealand's birds filled many mammal niches. Sometimes, in the absence of predators and competition, even original abilities are lost, as shown by Australasia's flightless birds—the kiwi, kakapo parrot and woodhen—which adapted completely to life on the ground. All in all, the Australasian region has been spared many of the violent ups and downs, invasions, superimpositions, blendings and extinctions which have so markedly afiected the flora and fauna of the world's other great zoogeo-graphical realms—and yet for all its small size it has a diversity of plants and animals rivalling any of them. What these are, how their evolution is understood today and their significant place in the broad picture of life on earth—all this is set down in an absorbing text by David Bergamini, a writer-journalist with a rare ability for developing the most fascinating aspects of his subject. The Editors of Time-Life Books have illuminated the book with many striking illustrations, including the first pictorial rendering of Thylacoleo, the cave lion long known only as a fossil skull. As the second volume in a series devoted to the major natural regions of the world and their wild-life, this is indeed a valuable book. Allen Keast Department of Biology Queen's University, Kingston, Ontario