How Do You Know About The Creatures On Our Planet?

No one knows how many species there are on planet Earth. Nearly two million have been identified and named, but biologists put the actual total at between three and thirty million (some go as high as eighty million in the belief that the tropical rainforests have yet to reveal their full complexity). Such a significant difference between the known and the potentially unknown presents us with a paradox: we have countless new species to discover and learn from in the coming years, but we are also losing species through our direct actions (or our indirect negligence) at such an alarming rate that species are vanishing before human eyes have had a chance to register their existence, much less give them a name. There is a well-known adage that asks: "If a tree falls in the forest and there is no one there to hear it, does it still make a sound?" Perhaps in light of our current predicament, we can also ask: "If an unknown species vanishes before it has been discovered, have we lost anything?" Our planet´┐Żs biodiversity is the result of more than four billion years of evolution. Species have evolved to exploit a range of habitats from thermal pools to the surfaces of glaciers, from ocean depths to mountain tops, and from humid tropics to dry deserts. However, during the course of evolution more than 99.99 percent of all the species that ever existed have become extinct.