Do We Still Need Nature?

Our reliance on the Earth's non-renewable resources of oil and other fuel and non-fuel minerals is well understood by most people. Yet, when caught in the tide of technological advances that seem to dominate our everyday lives, we can easily forget the extent to which the modern, industrial world still depends on the biological world: on both the ecological systems that we have already learned to manage, such as farms and orchards, and on those we have not.

A fundamental property of ecological systems is a certain mixture, or diversity of living things: we cannot expect to find deer or ducks in the wild in the absence of the interconnected web of other plants and animals on which their lives depend. Biological diversity, or biodiversity, is a term that is now commonly used to describe the variety of living things and their relationships to each other and interactions with the environment.

The notion of biodiversity encompasses several different levels of biological organization, from the very specific to the most general. Perhaps the most basic is the variety of information contained in the genes of specific organisms, be they petunias or people. Different combinations of genes within organisms, or the existence of different variants of the same basic gene are the fundamental "stuff" of evolution. At the next level is the variety of different species that exist on the Earth: a concept that includes the relationship of different groups of species to each other. Biodiversity also describes the varied composition of ecosystems, and the variety of different sorts of ecosystems that are found in regions of study that biologists call landscapes.

It has been clear for some time that at all of these levels of organization the rich biodiversity that has always characterized the natural world is today declining. The extinctions or threatened extinctions of many species are but the most visible and well-known manifestation of a deeper and more far-reaching trend. What has been less obvious to many people are the potential consequences of these changes.