There is a normal rate of extinction, which is known as the Background Extinction rate and is based on fossil records. Estimates for this rate range from one to ten species per year for the past 600 million years.Recently pesky humans (who else) are starting to have a profoundly adverse affect on this rate. Extinction rates based on Known (100% confirmed) Extinctions (birds, mammals and amphibians) for the past 100 years are 50 to 500 times higher than the BE rate. Worse still, If Possibly Extinct species are included, then this increases from 100 to 1000 times the rate, Which is frankly alarming. Further still, this is actually an extremely conservative estimate as it does not account for undocumented extinctions and there are still major gaps in knowledge of other species rich groups such as invertebrates, plants and fungi, which together compose the majority of all species. Bad humans. Bad.How are humans causing this? Simple. By destroying, degrading and fragmenting (in other words, using up) habitats of threatened birds, mammals and amphibians. In the last 20 years alone there have been 27 recorded extinctions. Ouch.If this trend continues, Earth will soon (relatively speaking) have far less species to speak of, which is a real shame as I for one find a certain wonderment in the fact ( for example) that there is 375 different species of Shark in the world today.
Aside from the problems humans are causing, I came to thinking that extinction is quite a tragic thing really in itself and after some searching was able to extract a list of all recorded extinctions since 1500 AD from IUCN’s Red List. This, much to my delight and then subsequent sorrow, opened my eyes to hoards of fantastically (and sometimes distinctly unimaginatively) named species I never knew existed but tragically we have lost over the centuries. The most infamous extinct animal in recent history of course has to be the Dodo but there are some crackers from yester-year, which are surely much more deserving of such celebrity status. Here’s a few:
The Big-Eared Hopping-Mouse,
Ascension Flightless Crake,
and Mysterious Starling.
Alas, never again will a housewife be petrified by a Big-Eared Hopping-Mouse, or a light bulb bothered by a Confused Moth, or a bust perched on by a Mysterious Starling or an Australian given a stern look by a Broad-faced Potoroo or patch of sky longingly gazed upon by an Ascension Flightless Crake. A tragedy of Shakespearean proportions.
And there are more; Many more. 799 to be exact and many of them equally as brilliantly named. Are we doomed to lose all our best-named species! Say it’s not true! The more species-rich Earth is the more downright daft names we’ll have to come up with. Think about it.
With such wonderfully named creatures in mind, surely there can be no greater incentive to stop our plundering of mother earth than the realisation that we once used to live in a world with Pallid Hairy Dwarf Porcupines, Queen Of Sheba Gazelle’s, Red-Moustached Fruit-Doves and Round Island Burrowing Boas. A world where Rubious Cave Amphipods lived in glorious harmony with Santa Lucia Giant Rice Rats, Tasman Booby’s and Aldabra Warblers.
Earth is a lesser place without them and will be lesser still if we bring a premature end to our current colourfully names species such as the elephant-nosed monkey, Pink fairy armadillo and African palm civet. Let’s keep Earth special and keep those Monkeys, Armadillos and Civets and everything else while we’re at it.
Dr. Dolittle wouldn’t have it any other way and isn’t there a little Dr. Dolittle in all of us?
Of course, us humans are indeed just a species and are no exception to the rule of extinction and so the obvious question is: Will the human race cause its own extinction?
Scientistic calculate that the human species in its present form can be expected to last at least another 5,000 years but not more than 7.8 million years. As previously mentioned, mammal species on average become extinct in 2 millions years based on historical data. However such arguments have embedded in them the assumption of a low probability that in any time period there will be a huge change in the environment of a species. This assumption surely cannot hold for humans in the next 100 years as we are highly likely to gain many more ways of affecting our environment.
You will recall from my definition of extinction that one of the causes is inability to cope with changes in the environment. We are of course changing our own environment rapidly now and will continue to do so, thus the question becomes: can we cope with the changes we make? If not we become the creators of our own downfall. Irony at its devilish best I’m sure you’ll agree.
You could, I suppose, argue that this would be a natural end for the human species as what else could possibly cause its extinction? A meteor strike perhaps? but I imagine that is just as unlikely as a globally catastrophic volcanic eruption or cataclismic earthquake.
Perhaps the human species will develope the ability to create a new hybrid human or super race, which then ends up wiping out the ‘original’ human species. Interesting thought. It would be a spectacular way to end it all. Then again, I suppose if its demise is inevitable then it may as well go out with a bang. The dinosaurs did after all and who are they to upstage humans.
It may be, by the time it’s ‘last orders’ for the human species, that they have managed to colonise another planet and are, in which case the Earth would just be a hushed void of silent seas, delapidated deserts and forlorn forests, slowly but surely regenerating just in time for the next ‘big thing’ in evolution.
WWF (World Wildlife Fund) http://www.panda.org/index.cfm
IUCN (World Conservation Union) http://www.iucn.org
Florida Museum Of Natural History http://www.flmnh.ufl.edu/fish/Sharks/sharks.htm