The rich diversity of life is one of the most striking aspects of our little blue planet! Biodiversity is a fairly new ‘buzzword’ that is used a lot these days by the media and in science, in fact the United Nations designated 2011-2020 as the UN Decade on Biodiversity! The term biodiversity, originally coined by the scientist and conservationist Raymond F. Dasmann in 1968, has a number of interpretations; it can mean the degree of variation of life forms within a given species (genetic variation), the number of species, ecosystem diversity or even the entire planet! The biodiversity of the Earth is thought to have never been higher than it is right now!
But how many species of organisms actually call Earth home? The truth is, it is impossible to know for sure! Currently there are almost 1.4 million species described and recognised by science, with around 15,000 new species being named every year! Amazingly around 70% of these 1.4 million species are thought to live in just 12 countries; Australia, Brazil, China, Columbia, Ecuador, India, Indonesia, Madagascar, Mexico, Peru, and Zaire. Yet we are still probably far away from the true number of species in actual existence!
Estimates of the actual numbers of species alive on Earth vary wildly! Some research estimates that there are around 2 million species in total, whereas other scientists put the figure nearer 100 million species! Charles Darwin Other research highlights that certain groups of organisms are grossly understudied and therefore under described by science. For instance early estimates of fungal species diversity on Earth were concluded to be about 1.5 million individual species, more recent research has, however, suggested that a figure closer to 5 million or even over 7 million species may be a more suitable number! A recent discovery suggests that scientific species databases might not include representatives from an entire Phylum of fungi species! Another enlightening piece of research estimates that 86% of the currently existing species on Earth and 91% of species in the world’s oceans still await discovery!
So despite our modern technological advances we really don’t know how many species are sharing this world with us! we should be remain mindful though that we must continue to protect the environment and the natural world around us to ensure we do not cause the unfortunate extinction of yet more species, before they are even discovered! In 1833, John Obadiah Westwood, a British entomologist, tried to guess how many species of insects there were on Earth. He extrapolated from England to Earth as a whole. He then wrote, “If we say 400,000, we shall, perhaps, not be very wide of the truth”. Fast forward to today, and explorers and scientists have found over a million species of insects and keep finding more every day. I wonder if in another 200 years, the estimates of 100 million species will not be looked on with the same level of naivety and that the natural world will continue to surprise us with its richness and diversity!