Our planet is, in a sense, even more crowded than humankind has realised. A new study estimates that there are in all at least 7.4 million species of life on the globe, and perhaps as many as 10 million. Of these, only about 1.25 million have so far been discovered and catalogued. We still, it appears, have a lot to learn.
To be sure, most of the unknown species are believed to be tiny invertebrates or else plant life. In the age of satellite photos and habitat loss, we can hardly expect to find any more creatures on the scale of the giraffe or the elephant (although the ocean depths do keep surprising us with exotic new life forms).
In a paper published in the Public Library of Science journal, researchers from Dalhousie University in Canada used advanced statistical methods to come up with an answer to the paradoxical question, "How many species remain uncounted?"
They concluded that "some 86 per cent of the species on Earth, and 91 per cent in the ocean, still await description".
This is a sobering reminder that for all our vaunted technology and so-called mastery of nature, humans are still surprisingly ignorant about much of the natural world around us. There are still a lot of discoveries, with who knows what consequences, waiting to be made.