Life's lucky 'kick start'

BBC News ^ | October 13, 2003 | Dr David Whitehouse

[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.

[js1138]

The phrase common descent may not have appeared on this thread prior to my use. Common descent and natural selection are the ideas held by nearly all evolutionists. The exact means and details are always being disputed.

[Dimensio]

Are you saying that if he had used all CAPS in his STATEMENT, it would have been more meaningful?

[Dimensio]

Or life could have started 6000 years ago as the bible indicates.

Or all life in the universe could have come into existence Last Thursday, as Queen Maeve indicates. What's your point?

[Right Wing Professor]

I'll just add, however, that to some evolutionists, anyone who questions any premise of unguided evolution from abiogenesis to Homo Sapien isn't just not an evolutionist, they're mentally deranged, effectively insane. I find that arrogance even more unreal.

What you see is a consequence of entrenched positions. The details of evolutionary theory are in constant flux; particularly so at present, since genomics is rewriting a lot of the more speculative detials of the interrelationships between organisms. However, evolutionists have seen this healthy re-evaluation of the details of evolutionary theory used as an attack on evolution itself, and tend therefore to be wary about such arguments, when they don't come from within biology.

As for 'guided' evolution; science looks for naturalistic explanantions first. We are nowhere near the point where we can say for any system that there is no way this could have evolved (in fact, for most biological systems, we have a fairly good idea how they evolved). People like Behe, who argue that because he can't think of a way for a complex system like a flagellum to have evolved, they must have been designed, are stepping outside of science, which does not give up in the face of uncertainty or insufficient data. Moreover, science, in first considering all naturalistic possibilities before considering other possibilities, is doing what pretty much everyone does all the time. When you lose your keys, at what point to you consider the possibility they have been stolen by a supernatural being?

[Dimensio]

Oh, really? Look around you! Do you think this is all some big accident?

I'm not sure if this qualifies as "argument from incredulity" or if it's just "argument by assertion" where you wave your hands around and say, "Of course it's true, can't you see it?!". In either case, it's not a logical argument.

Do you think that the millions in history who have been touched personally by their Creator are simply delusional?

Argument from anecdotal evidence. False dilemma fallacy. Strawman.

Do you think miracles that demonstrate God's sovereignty over His creation don't happen?

Incomplete question. There have been thousands of gods proposed and worshippe throughout human history. To which are you referring with your question?

Well, okay, that was something of a semantic nitpick. Since I, personally, lack belief in all gods, my answer would be "no" unless you have a very unusual definition of "God". Others on the "evolution" side of this discussion, however, may have a different answer.

Do you find it odd that we are all searching for the infinite

What "infinite"? I'm searching for a good way to complete a design project for an Engineering Economics class, a way to manage my finances properly and a way to get in better shape before my vacation to the Bahamas in December. I hardly have time amidst all that to search for the "infinite". I'll leave that to people who can dedicate the appropriate time and resources necessary to the search until such time that I'm able to give said search the time that it deserves.

though some find disparate answers to the same questions?

Wouldn't this weaken an argument for a "Creator"? You've got different people claiming to have found "evidence" for contradictory Creators.

In order to disprove God, you have to disregard history itself

Again, thousands of gods worshipped throughout history. Your statement, therefore, requires qualification.

In order to prove God, you have only to listen to eye witness testimony and the geological proof of events which corroborate their accounts.

I don't think that you're using the word "proof" to mean what everyone else thinks that it means. Anecdotal evidence does not "prove" the existence of any gods.

To believe these scientists, you have to take their word on events they did not witness to explain what they admit they don't understand.

Half right. They don't claim to explain events that they don't understand. If they didn't understand things, they wouldn't have explanations.

They seem very quick to say what the historical record isn't but they will never be able to give a definitive alternative that doesn't include either God or "luck".

"God" has no place in scientific explanations, unless your concept of "God" is far more limited than that of most people's. Science is the study of the natural universe. Events or entites that exist outside of the universe -- either in whole or in part -- cannot be addressed by science, so science cannot appeal to them as an explanation for anything.

You are free to choose who to believe. I'll side with God.

Which one?

[edwin hubble]

"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. "

This is a very big thought indeed.

Our Earth now has only a billion years or so of comfortably habitable conditions. Just imagine if we had had 2 billion more years of complex life in the natural history of Earth.

Another item raised: The reference to the 'self-regulating' properties of Earth and its climate...staying between the cold and warm states for the last billion years or so.
(...but nonetheless fluctuating in that range without human activity).

[Right Wing Professor]

I hate to leave the crevo threads at a point when they've, for the first time in months, been fairly civil, but I have a huge amount of work to do in the next week, so I won't be around for a while. See y'all.

[js1138]

When you lose your keys, at what point to you consider the possibility they have been stolen by a supernatural being?

I know for a fact that they are with the missing socks, probably engaged in something kinky that I don't want to think about.

[Right Wing Professor]

I know for a fact that they are with the missing socks, probably engaged in something kinky that I don't want to think about.

I figured out how to get around this. I only buy two kinds of socks; white crew socks, and black crew socks. I buy them in large quantities. So if individual socks go off to do unspeakable things, no doubt accompanied by the wife's pantyhose, I never know, since every white sock matches every other white sock, and ditto for the black ones

I call it 'don't match, don't tell'

[js1138]

I did the same thing, but the bypassed my defenses. Now I have socks of the same brand and age that are of slightly different length. I mean an inch or so. They fit ok, but inanimate objects will stop at nothing to thwart me.

[null and void]

Thank you.

I thought the thread needed some levity...

[BiffWondercat]

I think human society really took off after the invention of beer. HMMMM....

[BiffWondercat]

Type "biblical inconsistencies" into a search engine.
I wouldn't consider opposite statements a matter of timing.

[BiffWondercat]

The Iliad and the Odyssey have never been proven any more inaccurate than have been the Hebrew Testaments, do you therefore believe in the existence of Zeus and Ares and Athena and Poseidon? (Hey! he finally used HTML!) Not trying to stir up the Mars worshippers are you? HA!

[BiffWondercat]

When did cells get (grab) mitochondria? I was informed that they have their own distinct and separate DNA. Most likely from another lifeform cells assimilated. If this is correct, WHY? Wouldn't the nuclear DNA be enough to run a cell? Strange 'design' in my consideration.

Great posts!

[BiffWondercat]

Somethings don't have to change like Gators and Sharks. "They swim, eat and make, little sharks - and that's all they do!" Sorry Rich..

[BiffWondercat]

Solar sails. Welcome to TYPE II. Nah, that just crusing on the wind. We are a long way from Dyson's Spheres.

(Still freaked out at the old movie 'PHASE IV')

[BiffWondercat]

As little as I have studied, Gravity is but a 'theory' as well. Perhaps it could change or reverse itself tommorow.
But, having done many dumb things, like jumping from trees, cliffs, roofs, ect. I consider the evidence sufficient not to perform a swan off the 10th floor.....

Still can't wrap my brain around 24-25 dimensions yet...
String Theory is like 'Cat's Cradle' on the frontal cortex!

[BiffWondercat]

I read in Discover that someone said that water is not H2O but H 1.5 O (If someone can PRLY on how to sub/super script - most kind)

[CobaltBlue]

I was an insufferable, know-it-all, four-eyed, teacher's pet and nerd girl in high school. Surprising, eh? ;^)

Downhill from there.-g-