Microfossils challenge prevailing views of the effects of 'Snowball Earth' glaciations on life

May 26, 2009
This is an exposure of the Chuar Group in Carbon Canyon, Grand Canyon. Credit: Carol Dehler

New fossil findings discovered by scientists at UC Santa Barbara challenge prevailing views about the effects of "Snowball Earth" glaciations on life, according to an article in the June issue of the journal Nature Geoscience.

By analyzing microfossils in rocks from the bottom of the Grand Canyon, the authors have challenged the view that has been generally assumed to be correct for the widespread die-off of early life on Earth.

"Snowball Earth" is the popular term for glaciations that occurred between approximately 726 and 635 million years ago and are hypothesized to have entombed the planet in ice, explained co-author Susannah Porter, assistant professor of earth science at UCSB. It has long been noted that these glaciations are associated with a big drop in the fossil diversity, suggesting a mass die-off at this time, perhaps due to the severity of the glaciations. However, the authors of the study found evidence suggesting that this drop in diversity occurred some 16 million or more years before the glaciations. And, they offer an alternative reason for the drop.

This is Robin Nagy on a UCSB geology field trip to Death Valley. Credit: Susie Leska-Anderson

A location called the Chuar Group in the Grand Canyon serves as "one of the premier archives of mid-Neoproterozoic time," according to the article. This time period, before , is preserved as a sort of "snapshot" in the canyon walls.

The scientists found that diverse assemblages of microscopic organic-walled fossils called acritarchs, which dominate the of this time, are present in lower rocks of the Chuar Group, but are absent from higher strata. In their place, there is evidence for the bacterial blooms that, the authors hypothesize, most likely appeared because of an increase in nutrients in the surface waters. This process is known as eutrophication, and occurs today in coastal areas and lakes that receive abundant runoff from fertilizers used in farming.

"One or a few species of phytoplankton monopolizes nutrients at the expense of others," said Porter, explaining the die-off of diverse acritarchs. "In addition, the algal blooms result in high levels of organic matter production, which we see evidence of in the high organic carbon content in upper Chuar Group rocks. In fact, the organic carbon content is so high in the upper Chuar Group, oil companies were interested in the Chuar Group as a possible source of oil and natural gas." As a result of high levels of organic matter, oxygen levels in the water can become depleted, resulting in widespread "dead zones." Porter and colleagues also found evidence for extreme anoxia in association with the bacterial blooms.

In an accompanying article describing the process of discovering the microfossils, Porter described a highlight of the trip, "…when we rode through the rapids and descended into 'Powell's bowels' -- where the oldest rocks in the Grand Canyon frame the river passage. These rocks formed deep in the Earth approximately 1.8 billion years ago, and are very different in appearance from the overlying rocks."

The scientists braved extreme sun, rattlesnakes, scorpions, and dehydration to gather their data. They traveled by foot, helicopter, and river rafts, the last of which capsized on one occasion -- although the samples remained intact.

Source: University of California - Santa Barbara (news : web)

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QubitTamer
1.8 / 5 (10) May 26, 2009
Why the hell are these people researching climate or climate impacts, especially so long ago? I thought all the science was "in" and that there was absolute "consensus" about global climate modeling? If the models are right then how dare anyone continue to research for new information that could possibly challenge the Holy Models??? If the models say the complete glaciation killed off X amount of life then the work of these HERETICS on microfossils is deemed to be an ABOMINATION and they should all be forced to recant or be burned as witches, agents of Satan!

PPihkala
3 / 5 (3) May 26, 2009
QubitTamer, to provide information to those that don't understand your comment as a joke, the answer is that science is in fluid motion towards better understanding of matters and sometimes that involves making discoveries that call for reforming current theories. Sometimes it just takes quite some time before new ideas are rooted and can grow to blossoming trees, that some day might be superseded by newer, even prettier trees. Oh, make that better theories. But hardly ever can we say that we know everything about something and can stop researching it further.
Ethelred
2.6 / 5 (5) May 26, 2009
Take a look at QubitTamer's posts in the Global Warming threads. He is serious. He thinks that we should let the oceans rise. I think he has invested in future shoreline that is and sold short in London and other Lowlands properties.

In short he thinks all port cities should be inundated.

Ethelred
QubitTamer
2.6 / 5 (5) May 26, 2009
PPihkala,

Precisely! Beware anyone who tells you the answers are all in and there is consensus and now we must move to spend trillions of dollars to do one thing or another. Especially when it comes to the dynamic and ill understood mechanisms of variation in our billions of years old planetary climate.

And Ethelred, i grew up in New Orleans and saw my childhood home inundated from a natural event that mankind had no hope of stopping and was clearly ill-prepared to deal with. So what? Too bad... Sea levels rise and fall and people move right along with them and somehow keep managing to make babies and pay rent etc, etc, etc.

I no more believe that all port cities should be inundated than i think that we should all endeavour to have 20 children apiece to quadruple the population of humanity for a lark.
Ethelred
1.8 / 5 (5) May 27, 2009
. So what? Too bad... Sea levels rise and fall and people move right along with them and somehow keep managing to make babies and pay rent etc, etc, etc.


I see. So its OK to inundate low laying land by continuing to act STUPIDLY and do nothing to stop the problem.

New Orleans is not the only city with a problem. ALL port cities, all beach cities, and even many inland cities are less than 100 feet above the present sea level. That is trillions of dollars of human effort that will go under water if the temperatures continue to rise. Or trillions of dollars in building nation girdling systems of dikes.

I no more believe that all port cities should be inundated than i think that we should all endeavour to have 20 children apiece to quadruple the population of humanity for a lark.


So how are you going to pay for those twenty children you are having? By the way that would more than quadruple the population. For an alleged physicist you seem to be numerically challenged.

Ethelred
Ronan
5 / 5 (2) May 27, 2009
Hrm. I don't quite follow; I understand that this research indicates that there was a die-off before the Snowball Earth event(s) of the Neoproterozoic started, but...Is the implication that this is the ONLY die-off, and that there wasn't a similar (possibly even more severe) event once the glaciation began in earnest? Can that be ruled out?
Ethelred
3 / 5 (2) May 27, 2009
That far back in time its hard to rule anything out. There isn't much evidence left over a broad enough area. All the fossils are micro-fossils as it was way before the Cambrian Explosion.

Basically they are extrapolating from minimal evidence. The extrapolations look to fit known science. Its all the unknowns that are the problem with ruling things out.

Ethelred
trackactor
1 / 5 (6) May 27, 2009
Science as Holy writ sounds pretty dangerous and unscientific - time to kick out all the jams m**her f**kers!!!!!!!!!
QubitTamer
2.6 / 5 (5) May 27, 2009
Ethelred you seem to be unable to understand sarcasm or the Queen's english.

Go look up what a 'lark' is. Also, as soon as you pledge to donate 50% of your lifetime income from any and all sources to preventing sea level rise, i will pledge to help spend that money toward that end.

In other words, either put your money where your mouth is or shut up and read more carefully.

I am sure you will write back saying how you would never use your personal money towards this end because thats what big government is for.

GaryB
3 / 5 (4) May 27, 2009
PPihkala,
...
And Ethelred, i grew up in New Orleans and saw my childhood home inundated from a natural event that mankind had no hope of stopping and was clearly ill-prepared to deal with. So what? Too bad... Sea levels rise and fall and people move right along with them and somehow keep managing to make babies and pay rent etc, etc, etc.
...


Funny, but you are completely wrong about New Orleans. Scientists and Engineers had been predicting the risk for years before as well as warning that we should shore up the dikes etc. No action was taken and the city was sunk ... followed by a woefully inept federal response by an administration that couldn't manage its way out of a paper bag.

If anything, you're New Orleans tale is a support for heeding warnings and taking preventive action.
Ethelred
May 27, 2009
This comment has been removed by a moderator.
QubitTamer
3 / 5 (4) May 27, 2009
Ethelred,

Ad hominem attacks are the hallmark of the intellectually defeated.

I do much more than think about consequences by the way, for the last 20 years i have spent 1 to 2 weeks per year of my personal time and money on environmental improvement sites and projects. This past year i went back to the highlands of Ethiopia to help the local populace learn to better conserve their ever shrinking forest resources.

I think quite a bit about ecology and environmental issues and then i use what financial resources and time i am afforded to ACT upon them when immediate AND long term benefit can be achieved.
Birger
5 / 5 (2) May 27, 2009
Can we get back on topic please....it is well known that anoxic ocean conditions are correlated to several mass extinctions of marine life. The interesting part is that the extensive glaciations did not make the situation even worse. Apparently, the glaciers stopped well short of the Snowball Earth scenario. At this period -which may not have much in common with current climate conditions- the global system of atmospheric conditions and ocean currents apparently was robust enough to stop the equatorial ocean from freezing over despite increased global albedo, thus saving life from being restricted to a few refuges (such as hot springs) with liquid surface water. The mechanisms of this negative feedback process that kept the world from total freezeover would be fascinating to learn. I assume we need a lot of isotope "proxies" to reconstruct what processes held the glaciations in check.
Ethelred
2 / 5 (4) May 27, 2009
Ad hominem attacks are the hallmark of the intellectually defeated.


You wish. When people call me names they are defeated. If they are right I admit it. Not so you. Don't make foolish posts. Don't tell fairy stories. Then I will treat you differently. Post nonsense and tell fairy stories and I will point it out.

I do much more than think about consequences by the way, for the last 20 years i have spent 1 to 2 weeks per year of my personal time and money on environmental improvement sites and projects.


Like you claim to be a physicist?

. This past year i went back to the highlands of Ethiopia to help the local populace learn to better conserve their ever shrinking forest resources.


Another lark?

See what happens when you are disingenuous? You can't be trusted.

Now start thinking about rising seas. The consequences of them. The inundation of all land within 100 feet of sea level.

If you have a REASON for thinking this will not happen then post it. Quit stalling and posting uncheckable irrelevancies. You have written nothing that changes what I said. Post a link if you can because you aren't trustworthy. That's a fact and not ad hominem. You chose to snow people now you pay the consequence.

Oh dear, I am sorry. Its not 100 feet. Its 80 meters for Greenland and the Antarctic.

http://pubs.usgs..../fs2-00/

Go ahead Qubit. Post a link showing this is wrong. Or can the crap.

Ethelred
QubitTamer
2.6 / 5 (5) May 27, 2009
Ethelred,

You are a religious zealot who believes that somehow computer climate models can predict the future and the future to you is doom and gloom. I see billions of years of planetary history that cannot be wished away or ignored that tell me that mankind has no hope in hell of stopping ANYTHING related to global climate change. Again it's not that i don't care if sea levels rise 80 meters, it's just that i don't believe that humanity can stop it is all..

The world is huge, i have traveled it extensively and i get great joy in helping people improve their lives and ecologies on the scales at which i can actually see the effects of my labor.

You are blinded and consumed by fear it seems and have the desperate desire of every 5 year old that someone is going to be able to make it all better..

It's either going to be all better by itself or there's going to be 80 meters of sea level rise.

Either way, life will go on...

Sorry i can't get frothy at the mouth about all this like you do.
QubitTamer
2.4 / 5 (5) May 27, 2009
Ethelred if you are still confused:



http://en.wikiped..._hominem



To spell it out as clearly as i can, you can present all of the USGS, IPCC, Soros Foundation, whatever studies, models, etc that you care to and i will never ever engage in trying to prove them wrong because such exercises are pointless.


Why? Because i am absolutely 100% convinced that the ability to predict what the entire planets temperature and sea level state will be in 20, 50, 100, 1000 years is beyond the ken of mankind to do.
Ethelred
2 / 5 (4) May 28, 2009
You are a religious zealot who believes that somehow computer climate models can predict the future and the future to you is doom and gloom.


Sorry, wrong again. Not religious. I am agnostic. Based on the lack of evidence for pretty much anything religious.

I simply pointed out what WILL happen if the temperatures continues to rise. The evidence is that they will. Yes, you can bury your head in the sands of denial. The waters will still rise if the CO2 continues to rise. Show a reason for believing otherwise.

That's a REASON not Creationists like FUD.

I see billions of years of planetary history that cannot be wished away or ignored that tell me that mankind has no hope in hell of stopping ANYTHING related to global climate change


Yes Homo Sapien has been around for billions of years. Sure. Of course. Wait no that's wrong. We have only been around 100,000 years or so and metal users for 5,000. Heavy carbon burners for less than 200 years. We can cut back on burning carbon. It doesn't have to be expensive either. Well not the sort of expensive you imply.

Again it's not that i don't care if sea levels rise 80 meters, it's just that i don't believe that humanity can stop it is all..


Than start believing because that alternative is disaster. Denial is not the answer. Sarcasm about models is not the answer. Finding a way is the answer. I am for fission reactors myself.

We can do things. But only if we try.

You are blinded and consumed by fear it seems and have the desperate desire of every 5 year old that someone is going to be able to make it all better..


Not someone. Everyone or at least enough people that can do things about it. You posted a not a single thing that is verifiable. Nothing that is based on facts. Not a single word that shows me wrong in anyway. That is pretty poor posting indeed.

It's either going to be all better by itself or there's going to be 80 meters of sea level rise.


No. Its might not rise if the Sun goes quiet. That has happened before but there is no sign of it happening at present. Without a Maundar Minimum we must quit being IDIOTS. We are capable of it. Heck we have the Bomb for 60 years and it hasn't been used since 1945. Now we need to do the same in regards to excessive use of carbon for energy.

Go ahead and post some evidence that shows that we cannot do so. I asked you before and again you are trying to run a bluff.

Sorry i can't get frothy at the mouth about all this like you do.


No you get frothy like a Creationist. That first post of yours was DEFINITELY frothing at the mouth so claiming you can't do it is much like your claim of being a physicist, which seems to be straight out false. So how much of the other alleged personal experience been?

--------------------------------------------------------

Ethelred if you are still confused:


Not in the least. You are running a bluff. At best.

I know what ad hominem is. I know that is NOT always an admission of failure. I know that sometimes people really deserve being called foolish.

Quit acting like one. Quit playing fast and loose with facts. Start posting things that can be checked.

To spell it out as clearly as i can, you can present all of the USGS, IPCC, Soros Foundation, whatever studies, models, etc that you care to and i will never ever engage in trying to prove them wrong because such exercises are pointless.


Of course its pointless. You have nothing to support you except for Creationist like FUD. I only posted the USGS stuff to show how much the oceans will rise if it continues to get warmer.

But do go ahead and try anyway. Straight bluffs aren't getting you anywhere.

Why? Because i am absolutely 100% convinced that the ability to predict what the entire planets temperature and sea level state will be in 20, 50, 100, 1000 years is beyond the ken of mankind to do.


So you are in denial. Perfect evidence is not going happen. Adequate evidence is already here. Even former President Dumbass figured out the the world is getting warmer. The CO2 levels are rising and WE definitely are contributing. If we cut back significantly on our contributions there is every reason to think we can at least keep the main area of Antarctica from melting.

Oh, and you started this by bringing in things not relevant to the article. Going around denying GW is not the same as saying we are unable to do anything. You are acting EXACTLY like a Creationist. Posting off topic nonsense and then being surprised about being called on it. Then hinting that you know it was nonsense. Now saying its that we can't do anything.

You are the one with the religious leanings on this. You are acting, with a remarkable level of similarity, like a Creationist.

Quit spreading FUD. Assume that a solution is possible for there is no chance of reaching a solution if no one tries.

Keep giving me ones and I will keep doing the same for you. Tit for tat. You started that crap also.

Ethelred
GrayMouser
3 / 5 (2) May 28, 2009
Microfossils challenge prevailing views of the effects of 'Snowball Earth' glaciations on life

Ok, I'm missing something here. They are researching a die-off that occurred before the "Snowball Earth" period. So? How does this challenge the prevailing views?
QubitTamer
2.6 / 5 (5) May 29, 2009
Keep on hyperventilating Ethelred. Keep missing my point that I would be just as sarcastic and mocking if the subject was anthropogenic global freezing and that mankind was going to cause a return to snowball earth in under a century.

I don't post any facts IDIOT because there are no FACTS about future climate other than these 2:

1) The climate in the future will change

2) Our impact as a species on it cannot be accurately predicted.


Please, hyperventilate some more now. You are my favorite spewer of AGW drivel.
Ethelred
2.3 / 5 (3) May 30, 2009
Keep on hyperventilating Ethelred.


Trolls often have this delusion of yours. As a longtime Internet Warrior I consider this fun.

Keep missing my point that I would be just as sarcastic and mocking if the subject was anthropogenic global freezing and that mankind was going to cause a return to snowball earth in under a century.


Of course, you're a troll. I understood that some time ago. No actual sense of humor or personal beliefs, just a troll looking for a good time by jerking people's chains. Never actually contributing anything worthwhile to the discussion.

I find trolls entertaining.

I don't post any facts IDIOT because there are no FACTS about future climate other than these 2:


Fact. You are not a physicist.
Fact: you engage in ad hominem attacks.
Fact: The Earth is hotter than it was in the last few centuries.
Fact: The CO2 levels are higher than in the last few centuries.
Fact: Humans produce a significant fraction of the annual CO2 increase.
Fact: If things continue as they have since the beginning of the Industrial Revolution temperatures will continue to rise:
Fact: A continued rise in temperatures, especially at the poles, will cause ocean levels to rise.
Fact: If the Antarctic and Greenland glaciers melt the oceans will rise 80 meters.
Fact: We can cut down on CO2 emissions if we try.
Fact: Your post was off topic and a troll.
Fact: I pointed it out that its stupid to allow things to get worse. I did not call you stupid.
Fact: YOU, not me, got ticked off.

Fact: I got your scalp. See my new signature. Thank you for your surrender in your profile.

1) The climate in the future will change


Yes. If it continues as it has it will get hotter. Unless we don't listen to know nothings and do something to change things in a different direction.

2) Our impact as a species on it cannot be accurately predicted.


Depends on what is accurate enough. We can predict that future will follow the past if we don't change. You seem to feel that we should just give up unless of course that is just another troll of yours. Considering the low level of truth in your posts I can't treat any thing you say as something you really think. Trolls look for reactions not truth, its one way of telling a troll from a mere hothead.

Even on the Internet there are consequences to bad behavior. We can change the amount of CO2 we produce and YOU can stop trolling.

People can change.

Even you.

Its your choice whether it will be for the better or the worse. Continued trolling counts as worse but I do find it entertaining to twit trolls. I also like seeing people change for the better. So its a win win situation for me.


Please, hyperventilate some more now. You are my favorite spewer of AGW drivel.


I love the smell of burning troll. It smells like chicken.

Ethelred

QubitTamer

Quantum Physicist, torturer of AGW religious zealots like Ethelred because i laugh at his hysterics.
Ethelred
1 / 5 (1) May 31, 2009
They are researching a die-off that occurred before the "Snowball Earth" period. So? How does this challenge the prevailing views?


Well nearly anything about life at that time is new of course. They may suspect that the large amount of carbon that was sequestered in the die off might have contributed to a Snowball Earth. As opposed to the Snowball Earth causing the whole die off.

Makes some sense to me. If there was a Snowball period either the Sun got colder or the CO2 levels dropped.

Ethelred

QubitTamer

Quantum Physicist, torturer of AGW religious zealots like Ethelred because i laugh at his hysterics.
Steve_o
3 / 5 (3) May 31, 2009
Ethelred QubitTamer with as much energy as you two have spent bad mouthing each other you two could have come up with a better solution to solve current events. Or at least give a much better understanding on what is going on as far as global warming not so much as prevention but maybe a way to restore the loss life after the fact.
jonnyboy
1.8 / 5 (5) May 31, 2009
QubitTamer you are a bad boy for taunting the obviously handicapped liberal arts student, now leave EthelRed alone so she can finish her freshman classes at City U!
QubitTamer
1 / 5 (3) May 31, 2009
Ethelred you found a friend! Welcome Steve O, i see you cannot read either!

Please more! More! That last hyperventilation was just wonderful! Please respond with at least twice as much ranting! Oh great and Mighty Internet Warrior.

Lolz!
Ethelred
3 / 5 (2) Jun 01, 2009
QubitTamer you are a bad boy for taunting the obviously handicapped liberal arts student, now leave EthelRed alone so she can finish her freshman classes at City U!


Oh Jonny, your ignorance is showing. I am not the one that is lying about being a physicist. Nor is Ethelred what you think. Go look it up.

I love it when trolls make sexist remarks. It shows just how little they know.

Ethelred

QubitTamer

Quantum Physicist, torturer of AGW religious zealots like Ethelred

because i laugh at his hysterics.
Ethelred
3 / 5 (2) Jun 01, 2009
Ethelred QubitTamer with as much energy as you two have spent bad mouthing each other you two could have come up with a better solution to solve current events.


For a first post that was pretty silly. In case you didn't QubitTroll doesn't think anyone can do anything except rant. He made it pretty clear.

Try harder. Post something with meaning. Perhaps even on the original topic. Try to contribute something of value. At least it would be a good example for the know nothing AGD ostriches.

Ethelred

QubitTamer

Quantum Physicist, torturer of AGW religious zealots like Ethelred

because i laugh at his hysterics.
Ethelred
3 / 5 (2) Jun 01, 2009
Please more! More! That last hyperventilation was just wonderful!


Ah, the delusions of trolls. I await the next step. The one that comes when they finally notice that they lost the war already.

Please respond with at least twice as much ranting!


Can't do that since the only ranting has been yours. I thank you for the entertainment. Its so nice to run into a AGD that isn't pretending to think.

I don't even have to check your posts for signs of actual evidence since you haven't done anything but rant. And such poor rants. Perhaps you should look at some of Harlan Ellison's to learn how to rant with style and wit. Of course that would entail actually learning something.

Oh great and Mighty Internet Warrior.

Lolz!


It amazing how trolls think they are being original. So far I haven't seen anything from you that is worthy of the Troll Hall of Fame. Just bog standard efforts at junior high derision. Pitiful really.

If you don't show some better insults soon I will just have to move on. You surrendered already so all that is left is to see if you manage something unique.

Ethelred

QubitTamer

Quantum Physicist, torturer of AGW religious zealots like Ethelred

because i laugh at his hysterics.