Around 252 million years ago life on Earth suffered a major crisis: the greatest mass extinction known.
More than 90% of the species that can be tracked through the fossil record became extinct, the worse effects being in the sea. Whole successful groups of clades disappeared, like the giant sea scorpions which are probably the largest arthropods ever evolved,
Full biodiversity recovery took tens of millions of years and life was dominated by new groups, notably dinosaurs on land.
A recent isotope analysis at MIT on material from China has added startling new information.
It was known that the extinction was relatively quick as judged in evolutionary terms but the new data gives a time period of £60k years (+-48K). Also it was known that the extinction was associated with temperature rise and release of the 'greenhouse gas', CO2, but the new data suggest that the CO2 came as a single spike around 20K years before the start of the extinction and was gone from the atmosphere before it got underway.
The CO2 would have caused runaway global warming and sea surface temperature went up by a colossal 10C, Much of the CO2 would have been absorbed by the oceans acidifying them.
This sort of colossal-fast impact must have had a similarly spectacular trigger and the smoking gun is the Siberian Traps, one of greatest volcanic events ever recorded. This happened at about the same time as the Permian extinction and the next research will concentrate on trying to date the Traps more accurately.
I find this story fascinating, not just because I worked on evolution science but as an SF writer and wargamer.
The dying world lit by volcanic fire of larval flows on a continental scale is a fascinating backdrop.
Holly molly that is cool reseach (if Global warming could ever be described as cool?).
ReplyDeleteThe great extinctions are fascinating Col. especially as we may be in the middle of a new one.
DeleteStartling indeed, John. A rapid rise in C02 sounds like bad news. We should be worried if one happens again.
ReplyDeleteUnfortunately, we are responsible this time but on a lesser scale.
DeleteFAscinating.
ReplyDeleteCould you tell us your sources?
I remember my biology teacher speaking about it years ago, but then it was a mere theory ( about which I tended to agree)
There is an enormous amount of material on the Permian extinction but the latest paper is PNAS. It is summarised in Scientific American, I believe.
DeleteI heard Cthulhu was to blame...
ReplyDeleteDepends how much schnaps you've had. :)
DeleteI heard Morgoth and Sauron were pretty handy with volcanoes too ;-)
DeleteOh dear - maybe I have been smoking too much pipeweed?
The history of Life on Earth is the history of extinction Life Events. IIRC 99% of everything that lived is now extinct. Life is not guaranteed.
ReplyDeleteLiving is a dying business. 😀:)
DeleteROFLOL
DeleteGoing to live forever, or die trying.
It'll be one or the other Ashley.
DeleteIf you like apocalyptic backdrops John, you should have opened a window mid-afternoon! More on the way and CO2 prob, to blame this time too! I'm giving us 60-100 years, less if we continue fracking!
ReplyDeleteFortunately we are buggering up the environment on a lesser scale than the Siberian Traps. 4C is the last estimate I saw for 2100. It will be exciting times, though.
DeleteSounds like a good sci-fi scenario - Evacuate planet Earth! Can you get to your spaceship before the lava flow reaches it!
ReplyDelete