Wednesday 3 September 2014

Mass Extinction - Right Now! A Rant

I read some stuff earlier today about the 200 species or so of creatures that have disappeared from the UK country side in the past hundred years or so. Now if we think about the extinction of creatures like the Dodo and the Moa and the plight of white rhinos  and tigers, if we think about the demise of the thylocene (Tasmanian Wolf) and so on we could be  excused for thinking that we were facing a serious extinction event, sadly brought about  by humanity.

But that would be wrong, wouldn't it?

I know that we are doing some serious damage to the planet in terms of species dying out but I don't think we have  tipped the balance yet. A serious mass extinction event involves a lot of death. We haven't seen anything like it, not even in our best zombie apocalypse movies. In fact I don't think that we have  the intellect to imagine a mass extinction.

Take the Ordovician-Silurian event   (about 450 mya) which over a period  of about 1 million years wiped out something like 60% of all marine life. (Don't forget that most of known life was marine at that time). Shit, that's a a lot of death and all of this in critters that haven't even got a backbone.

Then again, there was the Devonian extinction (about 370 mya)  which killed off a lot of things over a number of different extinction events. If I seem a little vague it's because I'm not entirely sure from the record how many things were killed off. I think that it is reasonable to assume that much of it was marine still and that it was worse than the more famous K-T event that closed the book on most dinosauria.

The  Permian saw the biggest of them all according to fossil  record and academic view.Arguably, in this Great Dying, something like 96% of marine life and 70% of land vertebrates were killed off. That is a shed load of death. This all happened some 250 mya. Think about it. Only 4% of marine life survived. This is the event that saw the trilobites disappear for ever. It's like seeing the Great Barrier Reef turned into a marine desert - and I've never been there... Trilobites had been around in some form for about 250 million years. By comparison homo sapiens, us if you prefer, have been kicking our heels on the planet for about 2 million years.

Then the beginning of the Jurassic with 34% of marine genera disappearing. On land the dinosaurs survived and crocodiles...what is it with crocodiles because they are still around now?

But apparently large amphibians disappeared for ever. (How many large amphibians are you familiar with outside Japan and China)

Then there is the K-T. This is dinosaur bye-bye time. I'm not entirely sure what that really means because I'm not entirely sure where a dinosaur ends  and a  bird begins but what I do believe is that an asteroid smashing into the Yucatan peninsula some 65 mya opened up the world for the mammals and out of them came us. Not good if you are an Apatosaurus or anything else that a human , posthumously and with hindsight adds the appelation 'saurus' even if you know you are not a lizard!

Where does that leave us now. Well lets get back to the original premise.

Are we living in a mass extinction event right now?

Probably not.

But that is not to say that we will not move into such an event if we don't pay attention to the world that we are living in and abusing so badly. What would it take to kill off 95% of he world's animal life ( other than killing off an  appropriate percentage of the planets green plant life). Maybe a shift of 5C up or down in the planet's average temperature per ecosystem?

Most of our religions are ill equipped to deal with the issues because they are by definition  fundamentally humanocentric so that as we seek the afterlife, we give scant regard to the life of the world that follows us or the world that will follow humanity ( and / or mammals because we will probably all go together.)

That's enough for tonight. I will return.......

No comments:

Post a Comment