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Re: The Permian-Triassic Extinction



I just sent a whole long post - to Guy Leahy! Nothing like setting up the listserv to encourage discussion!

I read the article. It says that the end-Permian extinction occurred over a long period of time characterized by a deteriorating environment, environmental stress, and signs of stress among living organisms, without presenting a single detail of what they are arguing happened, let alone how we know how the environment and living organisms were changing over time.

They argue further that a shutting down of ocean circulation caused the planet to warm up, which made it harder to replace the oxygen marine organisms sucked out of the water, and caused microbes to saturate the water with hydrogen sulfide. Hydrogen sulfide is nasty stuff. This idea is very interesting.

It does not say how we know that the ocean circulation shut down. It does not know why they think hydrogen sulfide levels increased. The whole thing reads like one non sequitor after another. I understood that the shutting down of the ocean currents only became possible as the planets assumed their current positions, around the end of the Cretaceous era, or later. Whether that is true or not, a shutting down of the ocean currents does not cause planet-wide warming; it causes heat to stay near the equator while the northern and southern latitutes become cold and freeze over. The shutting down of ocean circulation causes an ice age, not global warming. The news that the planet warms up during an ice age would certainly surprise those of our ancestors who lived through Earth's most recent ice ages as well as the recent little ice age.

It is not explained what the warming of the earth has to do with replacing oxygen that ocean organisms "suck" out of the water.

The notion that that in turn causes ocean organisms to make hydrogen sulfide is the original non sequitor. What kind of common organisms even make that amount of hydrogen sulfide, and how would a lowering of oxygen levels that stressed all life on earth cause organisms to make more hydrogen sulfide?

As to the notion that the idea is interesting, is that its entire point? Is science now becoming about nothing more than asserting outrageous and interesting ideas?

I started looking at the links to related articles on the page, adn the next interesting idea that these people have is that the lowering of Earth's oxygen levels, as an ice age caused the earth to warm up, resulted in dinosaurs evolving modern birdlike lungs. Is there any evidence that all dinosaurs from the end of the Permian time had modern birdlike lungs?

Besides, didn't all that interesting hydrogen sulfide make it more than a little hard for the dinosaurs to breathe while it was killing 95% of all life on earth slowly over millions of years? I actually didn't know it could take sulfur dioxide in enough of a concentration to kill millions of years to slowly and gradually accomplish that, but supposing that is true... If they had modern birdlike lungs, a toxic gas like hydrogen sulfide would have killed the dinosaurs far sooner than any other land bound animal that had different lungs, and pre-mammalalian reptiles would have kept their dominion over the earth. The dinosaurs behind me in their cage cannot have anyone in the house cooking with teflon, burning candles, using plugin air fresheners, or spraying air fresheners, because those birdlike lungs process fumes very poorly and they would drop dead. Miners used to take small dinosaurs in cages into the mines to keep track of the air quality, because the birds died so much more quickly than people suffered any ill effects.

Well, this sure is more interesting than working on my genealogy project. I needed an interesting idea to wake me up.

Yours,
Dora Smith
Austin, TX
tiggernut24@yahoo.com
----- Original Message ----- From: "Guy Leahy" <xrciseguy@sbcglobal.net>
To: <dinosaur@usc.edu>
Sent: Saturday, October 21, 2006 4:04 PM
Subject: The Permian-Triassic Extinction





http://www.sciencedaily.com/releases/2006/10/061021115722.htm