HIS NAME is Lonesome George and he is one of a kind. He is unique in a literal sense, as the last known Pinta Island Tortoise (Geochelone nigra abingdoni) left on the planet. When George passes away, his kind will disappear from the web of life as if he had never existed. The same fate faces hundreds of other species of animals, plants, birds, marine dwellers and insects, driven towards extinction for a variety of reasons. George’s home in the Galapagos Islands off Ecuador was laid waste when imported wild goats cleared away the vegetation which kept the tortoises fed.
Human foolishness wiped out the flightless dodo from its island retreat in Mauritius, the birds killed off because it was easy to do so. The Red List of Threatened Species prepared by the International Union for Conservation of Nature lists thousands of species that have become extinct in the wild, are endangered or critically endangered and are now vulnerable because of ongoing threats to their habitats caused by human activity, climate change and other factors. The giant panda, blue whale, Asian elephant and mountain gorilla are all found there as are the Bornean orang-utan, snow leopard, Bactrian camel and black rhinoceros.
Researchers from the US and Canada reported this week that the Earth supports 8.74 million species of plants, animals, birds, fish and other single and multiple-celled creatures. But we have catalogued only 14 per cent of species on the land and a paltry 9 per cent of species living in the oceans. More than seven million species are unknown to science. This raises the startling question of how many of these missing species, like those catalogued in the Red List, are on a fast track towards extinction? How much of this biodiversity is in danger of being lost?
This is no trivial consideration. As unique species these unknown animals, plants and others have a unique genetic make-up, they have genomes that contain genes that may not exist in other known organisms. We can ill afford to lose this irreplaceable biodiversity. Plants provide the origins of many important medicines such as the anti-cancer drug Taxol, obtained from the Pacific Yew. Little-used wild rice species are being merged with cultivated varieties to improve yields and nutritional value.
We have such a limited knowledge of the biodiversity that is already available to us that one can only ponder what is being lost as species are squeezed into decline and extinction. We have given Lonesome George far too much company.