How many species live on the Earth?
Scientists estimate roughly 8.7 million, according to a 2011 study in the journal PLoS Biology, published by the Public Library of Science. The crucial point, however, is that approximately 83% of those plant and animal species have yet to be discovered. Scientists calculate that there are probably 6.5 million species living on land, and 2.2 million in the ocean, but that 86% of land-inhabitants and 91% of ocean-dwellers are still roaming at large undiscovered,
