Author(s): J S Singh
Biodiversity provides to humankind enormous direct economic benefits, an array of indirect essential services through natural ecosystems, and plays a prominent role in modulating ecosystem function and stability. Biodiversity is not uniformly distributed on the earth, and could comprise 5 to more than 50 million species. The current rates of species extinction are 1000–10,000 times higher than the background rate of 10–7 species/species year inferred from fossil record. Today we seem to be losing two to five species per hour from tropical forests alone. This amounts to a loss of 16 m populations per year or 1800 populations per hour. The anticipated magnitude of species loss has drawn worldwide attention, fueling attempts to rapidly assess and conserve biodiversity. Key processes of speciation, endemism, coexistence, extinction, and differential vulnerability of taxa and habitats are not adequately understood. Accuracy of estimates of the total number of resident species and current rates of extinction remains undetermined, and the impact of species deletions on ecosystem function and stability is still a subject of debate among ecologists. In its own right, the study of biodiversity is assuming the status of an interdisciplinary science with a growing body of concepts, testable hypotheses, exacting methodologies, and internalization of aspects of human sociology.