Earth's massive extinction: The story gets worse (http://www.physorg.com/news/2012-01-earth-massive-extinction-story-worse.html)
QuoteScientists have uncovered a lot about the Earth's greatest extinction event that took place 250 million years ago when rapid climate change wiped out nearly all marine species and a majority of those on land. Now, they have discovered a new culprit likely involved in the annihilation: an influx of mercury into the eco-system.
"No one had ever looked to see if mercury was a potential culprit. This was a time of the greatest volcanic activity in Earth's history and we know today that the largest source of mercury comes from volcanic eruptions," says Dr. Steve Grasby, co-author of a paper published this month in the journal Geology. "We estimate that the mercury released then could have been up to 30 times greater than today's volcanic activity, making the event truly catastrophic." Grasby is a research scientist at Natural Resources Canada and an adjunct professor at the University of Calgary.
Dr. Benoit Beauchamp, professor of geology at the University of Calgary, says this study is significant because it's the first time mercury has been linked to the cause of the massive extinction that took place during the end of the Permian...
250 million years ago the extinction event at the end of the Permian was the largest of the big 5 mass extinctions and virtually destroyed multicellular life on Earth. It is a staggering testimony to the tenacity of life and the effects of natural selection that the diversity we see around us today has developed from that choke point.
To that point it is even more fascinating that even under some of the most extreme conditions life is able to persist. It gives me great hope that the chemical chain reaction that we are part of is not unique. That life exists and thrives throughout the universe because natural selection is not bound to earth. I have hope that in our lifetime natural selection and the forces that drive evolution will be viewed and taught as concrete natural forces just like gravity and inertia.
Whenever I think of life in difficult habitats, I think of some of the deep sea creatures they've been finding lately. These are creatures living thousands of feet under the ocean surface in crushing pressure and total darkness.
http://news.nationalgeographic.com/news/2011/11/pictures/111121-deep-sea-worms-new-species-oceans-science-animals/
Quote from: Traveler on January 09, 2012, 05:05:40 PM
Whenever I think of life in difficult habitats, I think of some of the deep sea creatures they've been finding lately. These are creatures living thousands of feet under the ocean surface in crushing pressure and total darkness.
http://news.nationalgeographic.com/news/2011/11/pictures/111121-deep-sea-worms-new-species-oceans-science-animals/
How is something that light and squishy not crushed by all the pressure?
Quote from: Budhorse4 on January 09, 2012, 05:14:59 PM
Quote from: Traveler on January 09, 2012, 05:05:40 PM
Whenever I think of life in difficult habitats, I think of some of the deep sea creatures they've been finding lately. These are creatures living thousands of feet under the ocean surface in crushing pressure and total darkness.
http://news.nationalgeographic.com/news/2011/11/pictures/111121-deep-sea-worms-new-species-oceans-science-animals/
How is something that light and squishy not crushed by all the pressure?
Pressure is only a problem if the pressure outside an object is different from the pressure inside an object. The creatures living at these great depths do not feel this pressure any more than you do the 15lb per square inch you are subjected to when you stand by the sea. This is because there is an equal pressure inside their bodies as outside thus the pressure
differential is zero.
Some chemical reactions are effected by the high pressure and the creatures that live in a high pressure environment have evolved to cope with this. If they are brought to the surface they almost invariably die.
Quote from: Tank on January 09, 2012, 07:58:20 PM
Some chemical reactions are effected by the high pressure and the creatures that live in a high pressure environment have evolved to cope with this. If they are brought to the surface they almost invariably die.
You would think they would explode given the amount of pressure inside them, unless they equalise somehow.
Quote from: Stevil on January 10, 2012, 12:50:26 AM
You would think they would explode given the amount of pressure inside them, unless they equalise somehow.
(https://www.happyatheistforum.com/forum/proxy.php?request=http%3A%2F%2Fimages.nationalgeographic.com%2Fwpf%2Fmedia-live%2Fphotos%2F000%2F006%2Fcache%2Fpufferfish_673_600x450.jpg&hash=26a5500ae51466c6a71b16b12f022e25ef0c4351)
Not exactly on topic, just something brought to mind.
Quote from: Stevil on January 10, 2012, 12:50:26 AM
Quote from: Tank on January 09, 2012, 07:58:20 PM
Some chemical reactions are effected by the high pressure and the creatures that live in a high pressure environment have evolved to cope with this. If they are brought to the surface they almost invariably die.
You would think they would explode given the amount of pressure inside them, unless they equalise somehow.
A few do have unfortunate explosive issues when they get to the surface. Deep sea bottom dwellers don't usually have a method of positive buoyancy regulation a bit like cave dwelling animals often don't have pigments or functioning eyes. Sharks don't have swim bladders their livers have a lot of oil in them and they regulate this to obtain a neutral buoyancy.
Quote from: Tank on January 10, 2012, 08:21:53 AM
Quote from: Stevil on January 10, 2012, 12:50:26 AM
Quote from: Tank on January 09, 2012, 07:58:20 PM
Some chemical reactions are effected by the high pressure and the creatures that live in a high pressure environment have evolved to cope with this. If they are brought to the surface they almost invariably die.
You would think they would explode given the amount of pressure inside them, unless they equalise somehow.
A few do have unfortunate explosive issues when they get to the surface. Deep sea bottom dwellers don't usually have a method of positive buoyancy regulation a bit like cave dwelling animals often don't have pigments or functioning eyes. Sharks don't have swim bladders their livers have a lot of oil in them and they regulate this to obtain a neutral buoyancy.
That's both creepy and extremely fascinating