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.
I submit that they wouldn't know intelligent life if it came up and bit them in glutes. Why is it so much more plausible to believe that life is just a cosmic boo boo than to believe that we actually have a purpose ordained by our Creator?
Sounds like religion to me. Consider the number of times this article has the words "may be", "might have" or "could" in it( 7 ). But if one happens to 'believe' differently than this esteemed Doctor, they'd be considered an ignorant, backward fundamentalist.
Yes, that is the case with all the sciences. However, when 0% of empirical evidence suggests life rising 6000 years ago, while 100% of empirical evidence suggests life arose millions, if not billions, of years ago, the guessing process becomes much easier.
The early history of life is still an area of research where there's a great deal of uncertainty. In such a situation, it's reasonable that there be a plethora of competing, speculative hypotheses. The difference between this and religion is that religion seldom admits uncertainty that might be resolved later by human inquiry. It either dictates the truth, or it claims the truth is some mystery beyond human understanding.
I personally don't believe this hypothesis. I am most certainly not a fundamentalist.
More likely than not, yes.
Do you think that the millions in history who have been touched personally by their Creator are simply delusional?
Yes.
Do you think miracles that demonstrate God's sovereignty over His creation don't happen?
Yes.
Do you find it odd that we are all searching for the infinite, though some find disparate answers to the same questions?
No.
Why so? I am not a telepath..
There's uncertainty primarily because people are uncertain about the truth that's been told to them. Research the historical record of many early civilizations and you find strikingly similar themes. In some, you find geneological recording of lineage to creation itself.
The uncertainty we experience through time is from those who cut off their nose to spite their faces. The Bible has NEVER BEEN PROVED INACCURATE. There are some instances of timing that have been called into question but the geological and archeological records we've found through the years have corroborated Biblical accounts... despite the naysayers. God created the world in six days. Later in the Bible we read that a day for God can be 1,000 years. The real issue isn't the timing but the source. The point of the creation story isn't an exact reasoning of just how long it took but to give credit where credit is due.
Instead of working so hard to prove new ideas correct to change the historical record, it would be interesting to see how much we could learn by just examining the world around us and drawing conclusions.
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