Vestiges.
A fossil form of Ediacara called Fractofusus andersoni provides evidence of an ancient explosion of life.
Credit: Bing Shen/Virginia Polytechnic Institute and State University [VIA SCIENCE]
Posted on 01/04/2008 3:22:37 PM PST by neverdem
Vestiges.
A fossil form of Ediacara called Fractofusus andersoni provides evidence of an ancient explosion of life.
Credit: Bing Shen/Virginia Polytechnic Institute and State University [VIA SCIENCE]
Researchers have uncovered what they think is a sudden diversification of life at least 30 million years before the Cambrian period, the time when most of the major living groups of animals emerged. If confirmed, the find reinforces the idea that major evolutionary innovations occurred in bursts.
The main points of Charles Darwin's theory of evolution, which he carefully laid out in The Origin of Species 149 years ago, have stood the test of time. But where Darwin assumed that natural selection proceeds slowly and orderly--much the way Isaac Newton imagined a clockwork universe--modern investigations have shown that the process more resembles the chaotic world of quantum physics. Scores of new groups of species can appear within a few million years. By far the biggest and most famous of these events is the Cambrian explosion, a period between 542 million and 520 million years ago, when due to some still-unknown cause, the ancestors of nearly all extant groups, or phyla, of animals appeared.
Now a team of paleontologists from Virginia Polytechnic Institute and State University in Blacksburg think they've found a second great explosion of life. The researchers have performed the most detailed analysis yet of strange fossils from Australia, known as the Ediacara biota. They represent the oldest known multicellular organisms, which emerged about 575 million years ago.
The morphology of the Ediacara organisms is so different from that of previous life forms and from one another that they must qualify as several distinct new classes of species, the team argues tomorrow in Science. Many of the organisms, which resembled leaflike fronds and fractal forms, emerged abruptly over about 25 million years during the Avalon period, so the team has named the event the Avalon explosion.
The event is "a perfect match in time" to a sudden infusion of oxygen into the oceans, which may have sparked the explosion of marine biodiversity, says geobiologist and co-author Shuhai Xiao. Another possible stimulus, he suggests, is a warming of the ocean that occurred back then as an ice age was ending. Whatever the cause, there was one big difference between the Avalon and Cambrian explosions: The Cambrian produced groups that endure to this day, Xiao says, whereas the Ediacaran forms soon vanished.
The idea that the Ediacara fossils evolved a wide range of shapes and forms very quickly seems "reasonable and sound" in the context of evolutionary history, says evolutionary biologist Andrew Knoll of Harvard University. But that might not be the most striking aspect of the find. Rather, he explains, it's that these creatures evolved "much the same way as in later evolutionary radiations, large and small," suggesting that explosions in diversity might share similar dynamics.
Paleobiologist Richard Aronson of the Dauphin Island Sea Lab in Alabama says the study will spark new questions. Why, for example, was the Avalon explosion quashed, he asks, "but the Cambrian explosion prevailed and gave us life as we know it."
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“due to some still-unknown cause”
Most solid scientific theories rely on unknown causes.
This is like those reporters who always state "Global Warming has the ability to turn bread to toast if", and then go on to describe a situation where toast didn't happen, there is no bread, and something different is going on.
Gotta' protect those grants and not be thought of as a Fundy I suppose.
To look at these strange and ancient fossils is, literally, to look at creation - the creation of complex organisms - on earth. It is a great and profound mystery.
Causes are subjective and not usually observed in nature.
Whatever you do, make sure not to compare the "sudden infusion of oxygen into the oceans" to Genesis 1:2 which says that the "spirit of God [pneuma theou in the Greek Septuagint] moved upon the face of the waters." Pneuma can be translated as spirit, breath or wind. Pneuma theou would be the spirit of God, the breath of God or the wind of God. The image of God's wind blowing on the surface of the waters must be disassociated from any infusion of oxygen into the oceans or any explosion in species. /sarc
Of course not. Personally I favor more and better wild DNA segments being cast upon the waters by that wind ~ blown in from Outer Space.
I have a feeling that the theory of evolution will morph to the point that it is indistinguishable from (OE) creationism except for being philosophically atheistic.
Subjective and unknown are not the same thing. And not all causes are subjective, that’s an incredibly untenable position.
Is the cause of gravity unknown?
Is the cause unknown in kinetic theory?
So God's like a kid blowing out the candles on his birthday cake who doesn't get them all in one go? The Ediacaran biota looked completely alien and have been extinct for over half a billion years. I guess God had to take a second puff to get things going in the Cambrian.
Completely.
Causes of gravity can be approximated through mathematical formulas, and Higgs Boson provides an explanation.
You are welcome to try again.
Are you at least honest enough to admit that classical Darwinian theory is incorrect?
Explanations belong in history not physical science. Writing a tensor is hardly a cause of gravity.
Avoided one question, and ignored the point of the other.
A theory seeks to explain why something happens, does it not?
Do you think in all of history evolution has every produced the EXACT same result in separate populations?
No.
You grasp for straws.
The concept of natural selection doesn’t rule out the existance of some critical change that can be overwhelmningly successful and allow subsequent change at a more rapid rate.
Some term it punctuated equilibrium.
It took a lot of work to overcome those guys and bring in Ice Ages, continental plates, comets and meteors hitting the earth, etc.
Catastrophism was laughed at (see Velikovsky) even when it was at least partially correct, and so on. Darwin, with his slow and steady gradualism was able to supplant the prevailing orthodoxy, but he was wrong ~ and any criticism of his gradualist approach was taken as just another Fundy attack on the whole concept of evolution itself.
I thought a literal reading of Genesis would make the universe around 6000 years old?
I’d really like to jump into this thread, but I’m way too tired today to get into a flame war.
I’ll just say that I’m not impressed with the “punctuated equillibrium” theory of Gould and his colleague. Everytime there is data that doesn’t fit with standard gradualist Darwinism, you just give it a new scientific name to keep it in the scientific realm. See? It has a good name - like “covergent evolution”, and since evolution is the only explanate we allow it must be evolution.
As far as I can see there is no practical difference between the biolobical “explosions” being explained by “punctuated equillibrium” or by the biblical account of 6 “days” of creation.
Absolutely.
You just got to have faith.
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