Bill Laurance, James Cook University, Scientists have described around 1.5 million species on Earth - but how many are still out there to be discovered? This is one of the most heated debates in biology. Discounting microbes, plausible estimates range from about half a million to more than 50 million species of unknown animals, plants and fungi. This biodiversity matters because it could be used to fight human diseases, produce new crops, and offer innovations to help solve the world’s problems. Why is there so much uncertainty in the numbers? The biggest reason, I argue, is that a lot of biodiversity is surprisingly hard to find or identify. This has profound implications for nature conservation and for our understanding of life on Earth. Hidden biodiversity We find new species every day but the organisms that we’re now discovering are often more hidden and more difficult to catch than ever before.
Not surprisingly, the first species to be described scientifically were big and obvious. The earliest naturalists to visit Africa, for instance, could hardly fail to discover zebras, giraffes and elephants.
But recent discoveries are different. For instance, lizard species found today are generally smaller and more often nocturnal than other species of lizard. The tiniest of them, a thumbnail-sized chameleon from...
