Independent: How many species are there?
It was a question that fascinated Charles Darwin, and generations of biologists who followed him, with recent estimates ranging from a few million to as many as 100 million now scientists believe the true number of animals and plants is nearer to 5 million.
The incredible diversity of life on Earth and the sheer scale of the taxonomic problem have mesmerised biologists trying to figure out the total number of living species. But a group of biologists believes the...