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ASTEROID IMPACT PLAYED PIVOTAL ROLE IN RAPID PROLIFERATION OF LIFE
The Australian Centre for Astrobiology ^ | May 2003 | The Australian Centre for Astrobiology

Posted on 05/20/2003 11:01:28 AM PDT by Mike Darancette

Scientists studying rocks near an ancient asteroid impact structure in South Australian have uncovered evidence that could change current theories explaining how life on Earth rapidly diversified about 580 million years ago.

Dr Kath Grey of the Western Australian Department of Industry and Resources' Geological survey and an ACA associate researcher, Prof Malcolm Walter, Director of the ACA and Dr Clive Calver of the Tasmanian Department of Mineral Resources challenge the idea that 'Snowball Earth' - an intense period of glaciation about 600 million years ago, triggered the evolution of simple life forms into more complex and familiar species.

In the May edition of the international journal Geology, Dr Grey and her team put forward an alternative radical idea that 580 million years ago an asteroid impact played a pivotal role in this evolutionary jump. The impact, known as the Acraman event, smashed a hole in South Australia about four times the size of Sydney.

Up until then, for the first three billion years of Earth's 4.5 billion year history, bacteria and simple algae had dominated life on Earth. "Then almost overnight geologically speaking, the ancestors of modern day animals and plants appeared in the fossil record about half a billion years ago," Dr Grey said. "The big question is what caused the rapid proliferation of life at that time?"

Research by other scientists suggests the evolutionary burst of life between 600 and 540 million years ago was the result of an intense period of global glaciation. However, if the findings of Dr Grey's research prove correct, the cause could lie beyond our planet.

Dr Grey, who has studied fossil plankton (single-celled green algae) from drill holes across Australia, has found that, as predicted by the Snowball Earth theory, bacterial mats and a few simple spherical species of plankton were the only organisms that managed to survive the intense ice age.

"As the sea level rose at the end of the ice age, these spherical forms increased in number," Dr Grey said. "But there is no sign of a new species emerging at the end of the intense ice age to support ideas of the rapid diversification of life at this time."

Dr Grey believes it wasn't until about 20 million years later more than 50 new and highly complex species suddenly replaced the small number of simple species in the fossil record.

"What is really interesting is that the more complex spiny fossils appear just above a layer of rock in South Australia associated with the Acraman impact," Dr Grey said.

In a related study, Dr Calver found significant carbon isotope changes mirrored Dr Grey's observations. Prof Walter has also noted that patterns associated with the Acraman impact were similar to those of mass-extinction and recovery events, and that a large asteroid impact could have produced conditions ideal for evolutionary change.

"Later impacts, like the 65 million year old Chixulub collision in Mexico wiped out a diverse range of species, including the dinosaurs," Dr Grey said. "But with the Acraman impact, there were only a small number of species around and the time to cause a mass extinction event.

"Most of the species that did survive were highly resilient, and had the ability to remain dormant through the cosmic winter that followed. When conditions improved, these species had an advantage over their competitors and were able to proliferate and diversify."

Dr Grey and her team have reasoned that the ensuing plankton diversification must have played a vital role in the subsequent development of the animals dependent on plankton as a food source.


TOPICS: News/Current Events
KEYWORDS: asteroids; catastrophism; crevolist; godsgravesglyphs; life
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1 posted on 05/20/2003 11:01:31 AM PDT by Mike Darancette
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To: Mike Darancette
Genesis chapter 1
2 posted on 05/20/2003 11:07:32 AM PDT by shekkian
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To: Mike Darancette
"Most of the species that did survive were highly resilient, and had the ability to remain dormant through the cosmic winter that followed. When conditions improved, these species had an advantage over their competitors and were able to proliferate and diversify."

Hmmmmm. The problem with this theory seems to be that it provides no reason for why these forms weren't diversifying before the impact.

They don't really come out and say it, but it almost sounds like they're supporting Hoyle's theories about extraterrestrial origins for life on Earth.

3 posted on 05/20/2003 11:07:51 AM PDT by r9etb
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To: r9etb
Quix, I mean quick, check the Bible Codes!
4 posted on 05/20/2003 11:14:24 AM PDT by wideawake (Support our troops and their Commander-in-Chief)
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To: r9etb
It's just like how spacemen mated with apes to create the human race...it's happenning now!


Invasion of the body snatchers, 1978
5 posted on 05/20/2003 11:18:24 AM PDT by ffusco (Maecilius Fuscus, Governor of Longovicium , Manchester, England. 238-244 AD)
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To: Mike Darancette
Oh I struggle to be a true believing darwinite. Giant explosions lead to higher levels of complexity. This happens all the time in the real world. And if you don't see it, you must be a gullible 'creationist'!
6 posted on 05/20/2003 11:19:23 AM PDT by metacognative
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To: wideawake
Huh?
7 posted on 05/20/2003 11:26:23 AM PDT by r9etb
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To: wideawake
There is a poster named Quix who is a big believer in the "Bible Codes" movement - people who think that the Hebrew Bible consists of hidden anagrams.

The main popularizer of this movement, Michael Drosnin, just followed up the original bestseller with a new book which suggests that he has found evidence of extraterrestrial origins for human life in his anagrams.

It's caused quite a stir in some circles.

8 posted on 05/20/2003 11:52:41 AM PDT by wideawake (Support our troops and their Commander-in-Chief)
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To: r9etb
Sorry, post 8 was meant for you.
9 posted on 05/20/2003 11:55:58 AM PDT by wideawake (Support our troops and their Commander-in-Chief)
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To: r9etb
Sorry, post 8 was meant for you.
10 posted on 05/20/2003 11:55:58 AM PDT by wideawake (Support our troops and their Commander-in-Chief)
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To: wideawake
I know who Quix is/was. I never paid enough attention to him to know about the ET angle....
11 posted on 05/20/2003 12:03:01 PM PDT by r9etb
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To: r9etb
Terra forming and seeding into a nutrient rich environment?
12 posted on 05/20/2003 12:04:14 PM PDT by ASA Vet ("Those who know, don't talk. Those who talk, don't know." (I'm in the 2nd group.))
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To: PatrickHenry; Junior
.
13 posted on 05/20/2003 12:04:45 PM PDT by Chancellor Palpatine
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To: Mike Darancette
YEC skeptical bump to read later
14 posted on 05/20/2003 12:08:06 PM PDT by LiteKeeper
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To: r9etb
The problem with this theory seems to be that it provides no reason for why these forms weren't diversifying before the impact.

It's not that they weren't diversifying before the impact, it is that the existing forms were dominant under those pre-impact conditions and newly mutated forms really couldn't get a toe hold.

The impact both changed some conditions and wiped out a lot of the existing competition. And the race was on.

15 posted on 05/20/2003 12:19:36 PM PDT by jlogajan
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To: VadeRetro; jennyp; Junior; longshadow; *crevo_list; RadioAstronomer; Scully; Piltdown_Woman; ...
Ping.

[This ping list is for the evolution -- not creationism -- side of evolution threads, and sometimes for other science topics. To be added (or dropped), let me know via freepmail.]

16 posted on 05/20/2003 12:26:01 PM PDT by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: Mike Darancette
I thought it was going to play a pivotal role in the elimination of life? Make up my mind.
17 posted on 05/20/2003 12:33:12 PM PDT by Consort
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To: Consort
Make up my mind.

Catastrophic events do end life and lots of it, but not all life. All critters that occupy an ecological niche may completely disappear with species higher up on the food chain being effected disproportionately.

So, as you can see, when conditions return to the new normal new species will evolve to replace those that went by the wayside.

The Dinosaurs ruled the Earth for over 100 million years then disappeared in the blink of an eon, to be replaced by the Mammals as top creature.

18 posted on 05/20/2003 12:49:31 PM PDT by Mike Darancette (Soddom has left the bunker.)
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To: jlogajan
It's not that they weren't diversifying before the impact, it is that the existing forms were dominant under those pre-impact conditions and newly mutated forms really couldn't get a toe hold.

That's not what the lady said. She said that after the ice age and before the impact, there were really simple things like algae and bacteria and stuff, and no evidence of diversification:

"As the sea level rose at the end of the ice age, these spherical forms increased in number," Dr Grey said. "But there is no sign of a new species emerging at the end of the intense ice age to support ideas of the rapid diversification of life at this time."

Only after this asteroid impact did all this new spiny stuff supposedly show up.

Now, both the ice age and the asteroid were associated with huge extinctions, but only the latter produced the rapid mutation. Given that the same beasties were supposedly around in each instance, we'd expect either to have seen mutations after the first extinction, too; or no mutations after the impact.

These researchers appear to be saying that it was something about the asteroid that made the difference -- hence my reference to Hoyle.

19 posted on 05/20/2003 1:11:25 PM PDT by r9etb
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To: Mike Darancette
Actually, birds kinda ran things for a short time after the demise of the dinosaurs.
20 posted on 05/20/2003 1:15:39 PM PDT by Junior (Computers make very fast, very accurate mistakes.)
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To: r9etb
Environmental stress. It can be a powerful evolutionary catalyst.
21 posted on 05/20/2003 1:17:33 PM PDT by Junior (Computers make very fast, very accurate mistakes.)
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To: Mike Darancette
If true, where did the asteroid come from? I am under the impression that most, if not all, asteroids come from within our own solar system.

At work now so don't have time to research this.
22 posted on 05/20/2003 1:27:10 PM PDT by CobaltBlue
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To: Junior
Actually, birds kinda ran things for a short time after the demise of the dinosaurs.

Birds were top predator for a short time world wide and for quite a while in what was then a geographically isolated South America. But birds did not radiate many species to fill other ecological niches.

Mammals basically radiated to fill all ecological niches and quickly gained ascendancy.

When South America was finally connected to North America the Big Cats quickly gobbled up the Terror Birds.

23 posted on 05/20/2003 1:29:09 PM PDT by Mike Darancette (Soddom has left the bunker.)
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To: Junior
Environmental stress. It can be a powerful evolutionary catalyst.

But again -- the ice age they're talking about was an extreme environmental stress, too, and they note that diversification didn't occur afterwards. This particular claim seems to tie diversification the asteroid impact.

Which is fine, but let's just be clear about the underlying assumptions of the claim.

24 posted on 05/20/2003 1:31:29 PM PDT by r9etb
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To: CobaltBlue
If true, where did the asteroid come from?

That is not relevant to the premise of the article.

25 posted on 05/20/2003 1:34:24 PM PDT by Mike Darancette (Soddom has left the bunker.)
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To: Mike Darancette
I guess we are all Triffids
26 posted on 05/20/2003 1:38:49 PM PDT by AppyPappy (If You're Not A Part Of The Solution, There's Good Money To Be Made In Prolonging The Problem.)
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To: r9etb
There are a couple of ways of looking at this:

The ice age was a gradual thing and the various species extent at the time had plenty of time to adapt. The meteor impact threw that whole primordial paradise into a tizzy, stressing the environment and rendering some species extinct and opening up new ecological niches to the survivors.

Or, rapid speciation had already occurred in an isolated environment (a lake or small sea) while species in the outside world went on their fat, dumb and happy ways. When the asteroid hit it not only stressed the latter group but opened up the wider world (and new ecological niches) to the formerly isolated group.

Or, much like the last scenario, but with a group from the wider world being geographically isolated by the asteroid impact, and rapidly evolving in isolation (small groups evolve much more rapidly because changes are not as readily lost as they are in larger gene pools). Later this group rejoined the world at large.

27 posted on 05/20/2003 1:41:23 PM PDT by Junior (Computers make very fast, very accurate mistakes.)
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To: r9etb
That's not what the lady said. She said that after the ice age and before the impact, there were really simple things like algae and bacteria and stuff, and no evidence of diversification

There was no selection pressure favoring the new mutants. They were born and died out, ending their genetic influence, or limited to very small populations who didn't happen to leave a fossil record.

When conditions change, those few mutants who earlier may have had relatively expensive requirements compared to their simpler cousins, suddenly had a survival or re-population advantage.

I think you'll find that most higher complexity organism have initially higher "expenses" and therefore have a hard time getting a toe hold in a well settled niche. But when something comes along and upsets the apple cart, those few who've managed to pay that initial expense can now exploit that capital.

Complexity of organization requires an initial investment. Simpler organism can get into production quicker, and so tend to win the early races. But they are often less robust in the face of changing conditions. The more complex creature was paying for some unused abilities, and suddenly that is the difference between life and death -- or at least speed to repopulate.

28 posted on 05/20/2003 2:01:10 PM PDT by jlogajan
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To: jlogajan
To: f.Christian

fC ...

science (( no change )) vs the study of science (( change )) !

dh ...

That's a silly quibble. The universe does whatever it damn well pleases, and hasn't the slightest demonstrated notion of what a law is to constrain it. Insofar as what is demonstrable, natural laws are human inventions to help us think more effectively about nature. The claim that they are objectively existing things in and of themselves, is unproven and probably unprovable--as is likewise the claim that there is such a thing as "science" which exists independently of "the study of science".


1,398 posted on 05/14/2003 10:36 PM PDT by donh (u)

fC ...

reminds me of the oj juror lady ... "design (( dna )) --- what design (( dna ))" -- ? ? ? ?
29 posted on 05/20/2003 2:55:26 PM PDT by f.Christian (( apocalypsis, from Gr. apokalypsis, from apokalyptein to uncover, from apo- + kalyptein to cover))
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To: jlogajan
Well said. Think of it as Mother Nature kicking over the poker table and shooting out the lights.
30 posted on 05/20/2003 3:03:42 PM PDT by Mike Darancette (Soddom has left the bunker.)
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To: r9etb
They don't really come out and say it, but it almost sounds like they're supporting Hoyle's theories about extraterrestrial origins for life on Earth.

I thought that's where this article was going too - we're all space aliens.

I guess the theory of this article is that the asteroid slapped the earth out of it's torpor, kinda like the scene in B movies when the guy slaps the gal and yells "snap out of it"!

31 posted on 05/20/2003 3:05:26 PM PDT by colorado tanker
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To: jlogajan
retro spin ...

Liberalism is unrestrained (( evolution )) ideology (( manmade reason -- feelings )) ...

neo democrats ---fascists !

Motivation ...

these gods (( experts )) are UN - questionable -- UN accountable to nothing (( changes // whims )) -- no other (( atheists )) !

Make it up to suit their needs -- desires !

32 posted on 05/20/2003 3:14:35 PM PDT by f.Christian (( apocalypsis, from Gr. apokalypsis, from apokalyptein to uncover, from apo- + kalyptein to cover))
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To: Mike Darancette
>>That is not relevant to the premise of the article.<<

Oh, come on now. It's possible that life on earth came from somewhere else, hitching a ride on an asteroid or meteorite or whatever and you aren't a teensy bit curious as to where our ancestors were living and whether they are still alive, and what's become of them?
33 posted on 05/20/2003 4:38:14 PM PDT by CobaltBlue
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To: CobaltBlue
It's possible that life on earth came from somewhere else, hitching a ride on an asteroid or meteorite or whatever and you aren't a teensy bit curious as to where our ancestors were?

But there was life on Earth BEFORE the Impact Event and Ice formation described in the article, life that was ancesteral to life that existed afterward.

As to how life first formed upon this planet ......

34 posted on 05/20/2003 5:21:37 PM PDT by Mike Darancette (Soddom has left the bunker.)
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To: Junior
Actually, birds kinda ran things for a short time after the demise of the dinosaurs.

Come now. Let's get our stories straight. Birds are dinosaurs are they not?

Are Birds Really Dinosaurs?

Ask your average paleontologist who is familiar with the phylogeny of vertebrates and they will probably tell you that yes, birds (avians) are dinosaurs. Using proper terminology, birds are avian dinosaurs; other dinosaurs are non-avian dinosaurs, and (strange as it may sound) birds are technically considered reptiles. Overly technical? Just semantics? Perhaps, but still good science.

Isn't this making up stories just so much fun!!?

35 posted on 05/20/2003 6:15:06 PM PDT by AndrewC
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Comment #36 Removed by Moderator

To: CobaltBlue
It's possible that life on earth came from somewhere else, hitching a ride on an asteroid or meteorite or whatever and you aren't a teensy bit curious

No. Because that didn't happen

37 posted on 05/20/2003 6:17:30 PM PDT by billbears (Deo Vindice)
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To: Mike Darancette
But there was life on Earth BEFORE the Impact Event and Ice formation described in the article, life that was ancesteral to life that existed afterward.

Oh bother, such petty details!

Speaking of details. How deep was the ice sheet over snowball earth and how large was its extent?

38 posted on 05/20/2003 6:24:08 PM PDT by AndrewC
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To: AndrewC
Small Bang Theory.
39 posted on 05/20/2003 6:26:18 PM PDT by jwalsh07
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To: AndrewC
Okay. Birds are avian dinosaurs. The birds kinda ran things for a short time after the demise of the non-avian dinosaurs.

Better?

40 posted on 05/20/2003 6:26:58 PM PDT by Junior (Computers make very fast, very accurate mistakes.)
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To: Mike Darancette


Well...

I guess...

If I woke up in the morning and discovered that a huge asteroid was about to really knock the china outta the cabinet, the wife and I would surely engage in some "rapid proliferation" of our own.

TMMT
41 posted on 05/20/2003 6:29:15 PM PDT by The Magical Mischief Tour
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To: metacognative
Giant explosions lead to higher levels of complexity.


Exactly....I'm still waiting for a tornado to blow through the local junkyard and create my "Corvette".
42 posted on 05/20/2003 6:30:47 PM PDT by dagoofyfoot
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To: jwalsh07
Small Bang Theory


Big Bunk Theory!
43 posted on 05/20/2003 6:37:14 PM PDT by dagoofyfoot
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To: AndrewC
Discusses the Snowball earth without the BFR.

Snowball Earth Ala Harvard

44 posted on 05/20/2003 6:37:29 PM PDT by Mike Darancette (Soddom has left the bunker.)
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To: Mike Darancette
an al sharpton rock!
45 posted on 05/20/2003 6:40:43 PM PDT by liberalnot (what democrats fear the most is democracy .)
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To: Junior
Better?

Yes, but I feel that birds still might run things. Ever leave your nice beautiful recently washed and polished car under a tree?

46 posted on 05/20/2003 7:25:18 PM PDT by AndrewC
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To: Mike Darancette
Discusses the Snowball earth without the BFR.

Yes, thanks. I had skimmed that previously and missed the 1km reference. I also assume that BFR refers in a colorful manner to the extraterrestrial object. That or I am lost.

The link also points out they don't have any explanation as to how the freezing process was set off. Something has to "suck" the CO2 out of the atmosphere.

47 posted on 05/20/2003 7:33:13 PM PDT by AndrewC
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To: jwalsh07
Yeah, take your choice. But this theory does place Australia in the limelight in relation to life on Earth.
48 posted on 05/20/2003 7:39:40 PM PDT by AndrewC
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To: Mike Darancette
The Dinosaurs ruled the Earth for over 100 million years then disappeared in the blink of an eon, to be replaced by the Mammals as top creature.

Unless, of course, the fossil evidence is a well-made deception, not of human making. (Just being thorough here.)

49 posted on 05/20/2003 7:48:28 PM PDT by forewarning
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To: dagoofyfoot
I'm still waiting for a tornado to blow through the local junkyard and create my "Corvette".

Since absolutely nobody thinks this will happen, you may wait a long time. Your junkyard doesn't have cars giving birth to slightly different cars, and even then, you'd have to wait millions of years to see much happen.

50 posted on 05/20/2003 7:58:17 PM PDT by forewarning
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