Posted on 10/16/2003 7:33:43 AM PDT by AntiGuv
The Cambrian Explosion - when life suddenly and rapidly flourished some 550 million years ago - may have an explanation in the reaction of primitive life to some big event.
The explosion is one of the most significant yet least understood periods in the history of life on Earth.
New research suggests it may have occurred because of a complex interaction between components of the biosphere after they had been disturbed by, for example, the break-up of a super-continent or an asteroid impact.
Scientists say the life explosion might just have easily occurred two billion years earlier - or not at all.
Dramatic events
All modern forms of life have their origin in the sudden diversification of organisms that occurred at the end of the so-called Cryptozoic Eon.
Scientists have struggled to explain what might have happened in the previous few hundred million years to trigger such a burst of life.
Certainly, it was a period of history that witnessed the assembly and break-up of two super continents and at least two major glaciation events. Atmospheric oxygen levels were also on the rise.
But what actually caused the Cambrian Explosion is unknown.
Writing in the journal Geophysical Research Letters, Dr Werner von Bloh and colleagues, from the Potsdam Institute for Climate Impact Research, present a new analysis of happened.
They suggest that "feedback" in the biosphere caused it to jump from one stable state without complex life to one that allowed complicated life to proliferate.
"We believe that there was a change in the environment - a slow cooling of the system - that caused positive feedback that allowed the conditions for complex life," Dr von Bloh told BBC News Online.
Self regulation
Using a computer model of the ancient Earth, the researchers considered three components of the biosphere, the zone of life.
These were single-celled life with and without a nucleus, and multicellular life. Each of these three groups have different environmental tolerances outside which they cannot thrive.
The computer model showed there were two zones of stability for the Earth - with or without higher lifeforms - and that 542 million years ago the planet flipped from one to the other.
What caused the flip is not clear. It might have been a continental break-up, or even an asteroid impact.
There is some indication that the Moon suffered a sudden increase in impacts about the same time as the Cambrian Explosion. If so, then the Earth would have been affected as well.
This latest analysis also provides some support for the Gaia hypothesis - the idea that the biosphere somehow acts as a self-sustaining and regulating whole that opposes any changes that would destroy life on Earth.
Intelligent beings
Dr von Blow says that after the Cambrian Explosion there has been a stabilisation of temperature up to the present, and that the biosphere is not playing a passive role.
He also adds that there is an intriguing implication from his research which suggests that had the conditions been only slightly different, the Cambrian Explosion could have occurred two billion years earlier.
An early explosion would have meant that by now the Earth could have developed far more advanced intelligent creatures than humans.
Alternatively it could still be inhabited by nothing more complex than bacteria.
Dr von Bloh says that it will be of great interest when we find other Earth-like worlds circling other stars to see if they have had their own Cambrian explosions yet.
The timing of such events has implications for the search for intelligent life in space, he says.
The words were not directed at you in particular.
Go away, Junior. The Iliad and Odyssey were fiction when they were written and were considered fiction by their intended audience. The Testaments were written as fact and accepted as fact by their audience. Those who haven't been able to disprove the scriptures (and let me tell you, MANY have tried) have invariably failed or hung their hat on irrelevancies. Your continued attempt to spin your way out of your erroneous comparison compounds the observation of your ignorance.
As to the rest of your post... I disagree with 999.9% of what you said. In case you don't understand, that means I disagree with what you said and another 10 things you didn't say.
Both previous examples - the Homeric poems and the Hebrew testaments - merely fall somewhere between these two extremes.
Because you say so. Well, I'm convinced now. You've certainly proven your scholarship to make such an assertion!
Whether or not either were intended as fact or as fiction does not alter the analogy in the slightest. A psychotic in the mental ward could scribble out an account he believes to be true, but that makes it no more true for his belief.
Clearly, however, I was wrong to provide options above. You are not either dimwitted or dissembling. You are clearly a dimwit. To be honest, I suspected as much when I wrote that but wanted to be kind.. Like I implied, there is no point in debating with the faith of dimwits and I am content to leave any interested observers to draw whatever assessment they see fit.
Have a nice day.
He hasn't. Look around, it's everywhere. I stated that God can't be proven, not that there was no evidence of God. As a Professor I would have thought you understand the difference between proof and evidence.
Why, having created an intelligent being, would you want you own existence not to be subject to that being's intelligent inquiry?
God's existence is not subject to our intelligent inquiry, although I believe actual intelligent inquiry into his word will show us that God does exist. Our belief subjects us to God. If one doesn't believe in God, this in no way affects God's existence or non-existence, only our response to the conclusion we've reached. If God's existence were dependent on our intelligent inquiry, then we would in fact be God, as we would have the power to create or destroy God himself.
I think that's more a reflection of the nationality of the researchers than the science. Germans embraced Romanticism more than any other people, and have never really let go of it. One can almost hear the voice of Dr. Strangelove saying "by now ze Urth could have deffelopt var more atfanst intellishent critschures..."
For the little 'g' gods that man has created, I would have to agree. But I'm talking about the big "G" God. If he exists, it's by his own power and not our influence.
Can you be a little more specific?
As a Professor I would have thought you understand the difference between proof and evidence.
As a professor, I'm far too well aware that people often try to conceal their ignorance with condescension.
God's existence is not subject to our intelligent inquiry, although I believe actual intelligent inquiry into his word will show us that God does exist.
This is statement is self-contradictory.
If God's existence were dependent on our intelligent inquiry, then we would in fact be God, as we would have the power to create or destroy God himself.
We can inquire as to the existence of black holes; if we decide they don't exist, that does not annihilate every black hole in the universe. It just means we were rational but wrong.
If they fill in the gaps with their beliefs and they're Christians...
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