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.
Hi Napolean. Are you named after the famous emperor?
Now who's being unpersuasive.
A large number of Christians accept the Pope's word on issues like this as definitive.
Nail, head etc.
I have no problems believing in God and, at the same time, accepting the theory of evolution. I have no need to prove the existence of God to anyone- I accept it on faith. I do have a need to see evidence before I accept a scientific theory, and I haven't seen anything with better evidence to explain how we got here than the theory of evolution.
Ahh, but creationists aren't generally attacking the science behind evolution because they believe in vigorous peer review- they're attacking evolution based on ideology. Big difference.
Then it must be so.
I hope you'd agree that if we continue along this most recent line of discussion, then we should move into the 'religion' forum.
Well, many Creationists don't count Catholics as Christians.
Roman Religion
The indigenous Italic religion, which was the nucleus of the religion of ancient Rome, was essentially animistic. It depended on the belief that forces or spirits, called numina (sing., numen), existed in natural objects and controlled human destiny.
In the beginning of the historical period, when Italy was dotted with small agricultural communities, the family and the household were the basic religious units. Everything vital to the continuance of human life had its numen and appropriate rite. For the perpetuity of the family, the Italian farmer made offerings to the genius of the family. For the safety of the household he worshiped Vesta, the guardian spirit of the hearth fire; the lares and penates, guardians of the house; and Janus, guardian of the door. To protect the boundaries of his property he honored Terminus. To insure an abundant harvest he held various festivals throughout the year. To placate the spirits of the dead he made offerings to the lemures, to the manes, and to the deities of the underworld. In performing these religious ceremonies the head of the family acted as the priest and was assisted by his sons and daughters.
When these families coalesced into tribes and then a state, the family cult and ritual formed the basis of the state cult and ritual. Vesta had a community hearth, the penates a community storeroom, Janus a holy door in the Forum. Rome, which was theoretically one family, was ruled by its king, who as such was head of the family and chief priest. The king was assisted in his duties by his “sons and daughters,” the colleges of priests and priestesses. They elaborated and recorded the rituals necessary for the propitiation of the gods and regulated the state ceremonies and the ceremonial calendar. The official clergy included the pontifex maximus, the rex sacrorum [king of the sacred rites], the pontifices, the flamens (see flamen), and the vestal virgins.
Source: The Columbia Encyclopedia, Sixth Edition. 2001.
I don't have time to be chasing the rest of your demands for quick citations. I have a background in this area... you wish me to disavow this background and seek someone else's. This is enough of an excerpt for you to understand the truth. The gods, as "worshiped" by these ancient societies, were a source of national pride but not the object of divine help.
I lump Judeo-Christianity together in its persecution. One came from the other.
Not so (at least not the ones I know). We take issue with calling something "settled" by science when the method to arrive at the conclusion is specious, at best. If someone can provide a theory of evolution without the holes and "leaps of faith", I think you will find creationists accomodating to find out what it means spiritually.
Until then, though, we're not accepting the conclusions of junk science.
You succeeded... I'm speechless.
They were also a major source of income. I suspect the educated of every time and place have been skeptical of dial-a-god, the idea that prayers would literally be answered by divine intervention. (I have no proof that this never happens, but I haven't seen anything to make me believe it.)
OUR minds are closed? I sense projection...
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