ABSTRACT
Biodiversity is a recent concept, life on Earth a very ancient phenomenon. The history of both have fuelled awareness of a global environmental crisis. This chapter covers:
The word biodiversity was coined in the mid-1980s to capture the essence of research into the variety and richness of life on Earth. The word is now widely used, its rapid establishment in science and popular culture an indication of the importance of the topic but also a source of confusion. First, biodiversity is the richness and variety of life on Earth. The flowers and insects and bacteria and forests and coral reefs are biodiversity. Second, biodiversity is an area of scientific research, including both description and measures of diversity and explanations of how this diversity is created. Biodiversity has been increasingly used as a conceptual focus for conservation policy and practice in response to one of the strongest themes underpinning the founding work on biological diversity, species extinction and ecosystem loss, brought to global prominence by the Rio Earth Summit. The variety of life on Earth can be investigated at different levels: genetic variation, the numbers of species, the extent of ecosystems. Nature’s creative and destructive forces include ecological and evolutionary processes. Current degradation of biodiversity is driven by human pressures and conservation responds with protective laws, reserves and refuges in captivity. The purpose of this book is to provide an introduction to all these topics. Chapter 1 outlines the history of biodiversity, both as a concept and the story of life on Earth up to the current crisis. Chapter 2 describes the ecological and evolutionary processes that spawn this diversity and govern its distribution. Chapter 3 provides an inventory of how biodiversity can be classified and quantified. Chapter 4 describes recent extinctions and their causes, natural and human. Chapter 5 outlines policy and practice to conserve biodiversity.
