Origin and Early Evolution of Life draws on evidence from molecular genetics, the structure and function of extant organisms, and geology. It covers the period from about 4 billion years ago, when life is thought to have originated, to about 600 million years ago when multicellular organisms first arose. There are significant gaps in our understanding of the earliest evolution of life forms, but an insight into the topic leads to a more profound understanding of life itself. Particular emphasis is placed on the fact that although life arose very soon after the origin of the Earth, it was...

This book is written for ecologists and protozoologists. Ecologists who study environments and biotic communities in which protozoa are im ponant should find this book especially useful. During the last decade it has become clear that protozoa play important roles in natural eco systems, but few ecologists have a feeling for the functional properties and the diversity of these organisms. Protozoa pose or exemplify many general problems of population and community ecology, and of evo lutionary biology. In most respects the general ecological propenies of protozoa are not fundamentally...