Biodiversity
Scientific certainties and uncertainties
When researchers analysed a small sample of water from the Sargasso Sea in early 2004 they found it contained 148 new species of bacteria. The sample was taken from water famous for its lack of diversity. Modern scientific methods are changing our fundamental ideas about biodiversity.
We are beginning to understand how little we know.
Scientists believe that the sheer diversity of life is richer now than it has been in any other period in Earth's history. They know diversity naturally increases over time, then some catastrophe - an asteroid or volcanic eruption - reduces it for a while. The most famous mass extinction claimed the dinosaurs.
Right now the world is losing huge numbers of plant and animal species and this loss is accelerating. It will soon approach previous mass extinction rates. But there is a big difference between the current loss of biodiversity and previous extinctions. Physical events caused mass extinctions in the past. One life-form is overwhelmingly responsible for present-day extinctions - humans - you and me.