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BIODIVERSITY DEFINED

Biodiversity refers to the broadly diverse forms into which organisms have evolved and is considered at three levels:

THREATS TO BIODIVERSITY

Currently, more than 10,000 species become extinct each year. While precise calculation is difficult, it is certain that this rate has increased alarmingly in recent years. The central cause of species extinction is destruction of natural habitats by humans.

Human survival itself may depend upon reversing this accelerating threat to species diversity. Among the millions of undescribed species are important new sources of food, medicine, and other products.

When a species vanishes, we lose access to the survival strategies encoded in its genes through millions of years of evolution. We lose the opportunity to understand those strategies which may hold absolutely essential options for our own survival as a species. And we lose not only this unique evolutionary experience but, emotionally, we lose the unique beauty and the unique spirit which mankind has associated with that life form. Many indigenous human cultures have also been driven to extinction by the same forces that have destroyed and continue to threaten non-human species. It is estimated that since 1900, more than 90 tribes of aboriginal peoples have become extinct in the Amazon Basin.

Nearly every habitat on Earth is at risk: the rainforests and coral reefs of the tropics, the salt marshes and estuaries of our coastal regions, the tundra of the circumpolar north, the deserts of Asia and Australia, the temperate forests of North America and Europe, the savannas of Africa and South America.

Tropical rainforests, for example, are among the most diverse of all terrestrial ecosystems. Covering only 7% of the planet's surface, these forests comprise 50% to 80% of the world's species. 40 million to 50 million acres of tropical forest vanish each year - about 1.5 acres per second - as trees are cut for lumber or land is cleared for agriculture or other development. It is estimated that perhaps a quarter of Earth's total biological diversity is threatened with extinction in the next 20 to 30 years.

THE ACADEMY'S COMMITMENT

The California Academy of Sciences is a leader among the world's institutions for research in evolutionary biology. Staff researchers study biodiversity worldwide, describing more than 100 new species every year. Current projects include work in La Amistad Biosphere Reserve, Costa Rica; coral reefs of New Guinea and Madagascar; deserts of southwestern Asia; and Socorro Islands off the west coast of Mexico.

Approximately 1.4 million species of plants and animals have been described by scientists. Conservative estimates suggest that at least 5 million remain to be identified-the vast majority of them in the tropics. Fewer than 1500 biologists worldwide are now qualified to identify tropical species. If ever there was an urgent requirement for this expertise, it is now, in this time of rapid environmental erosion.