Posted on 12/18/2001 5:07:16 PM PST by Map Kernow
LONG-LOST relatives of the human race have been traced for the first time. They live at the bottom of puddles. A family of humble microbes has been found to carry a special signalling gene that was previously known only in the animal kingdom. The discovery suggests that the single-celled creatures represent a vital staging post in evolution and that all animal life on Earth descended from something very like them.
The survivor from our ancient ancestors is the collar flagellate or choanoflagellate — a microscopic organism that uses a sperm-like tail to swim through shallow water, grazing on bacteria that lodge in its feeding “collars”.
Its remarkable evolutionary legacy, which stretches back at least 600 million years, has been identified by researchers in the US. Today 150 species of collar flagellates exist around the world, but evolution also gave rise to a more complex lineage that eventually led to the animal kingdom.
“They are the closest nonanimal organism to animals,” said Sean Carroll, Professor of Genetics at the University of Wisconsin-Madison, who led the research. “They are to animals what chimps are to humans, and by studying some of their genetic characteristics, we can begin to make some strong inferences.”
In the study, published today in the Proceedings of the National Academy of Sciences, Professor Carroll and his colleague Nicole King analysed proteins from a species of collar flagellate called Monosiga brevicollis. They located a type of signalling gene, receptor tyrosine kinase (RTK), which sends messages to other genes telling them to become active or making them dormant. It is almost identical to similar version found in animals as diverse as humans and sponges.
The findings support strongly the idea that many genes that animals use today were already in place and available on the eve of animal evolution, but changed in function with the step forward to multicellular organisms with distinct body plans and systems of organs.
The microbes, which measure five thousandths of a millimetre in diameter, are protazoans — simple organisms that were once regarded as animals but are now generally considered to be part of a separate kingdom, the single-celled protists.
Scientists consider the moment at which multi-celled animals, or metazoa, evolved from the protozoans to be one of the turning points in the history of life on Earth. The process is thought to have taken place about 600 million years ago.
“The question is, who were the ancestors of animals and what genetic tools did they pass down to the original animals,” Professor Carroll said. The evolution of the metazoa from the protozoans is one of the milestones in the history of life. To build a multicellular organism compatible with a multicellular lifestyle is something that is very difficult. It takes a lot of genetic machinery to do that, and you have to ask the question, did it all arise when the animals came along, or was some of it in place earlier? “We’re starting to get a glimpse of the genetic tool kit we have in common. In choanoflagellates, we’ve found genes that previously were believed only to exist in animals. It’s a confirmation of the idea that the genes come first, before their exploitation by organisms.”
The study concludes: “We have discovered in M. brevicollis the first RTK, to our knowledge, identified outside the metazoa. The architecture . . . resembles that of RTKs in sponges and humans and suggests the ability to receive and transduce signals. Thus, choanoflagellates express genes involved in animal development that are not found in other eukaryotes (complex organisms), and that may be linked to the origin of the metazoa.”
Most certainly science uses assumptions to draw conclusions. Scientific proof is often mathematics based. Mathematics contains assumptions (axioms, postulates) stated up front. Physics posits matter and/or energy. It offers no proof that either actually exists, nor can it.
I really don’t mean to be condescending, I am just pointing out a fact: ID is not within the realms of science.
I suggest that you read “Darwin’s Black Box” by Behe and “Mere Creation” By Dembski. The men who wrote these are apparently very intelligent and knowledgeable in their fields. They have obviously confronted scientific facts that current theories cannot explain, so they invoke “The Designer”. But by introducing an outside force, an intelligent designer, they have stepped out of the bounds of science. It may feel better to believe in this ID, but feeling good is not very scientific.
Spend some time in examining Dembski’s “Explanatory Filter”. If you can’t see that this is a “god of the gaps” solution, try entering with the filter with some data, but pretend that you have no more knowledge then what was available 100 years ago. You will find a great number of things falling through to ID, but if you reenter the filter with today’s knowledge, you stop at laws.
Amazing how the “god of the gaps” gets smaller everyday.
This will depend on you definition of "nothing" (and I don't mean to sound like some Clinton smartass about what "is is"). The nothingness of outer space isn't. You can't make the assumption that the universe was created out of nothing -- well, you can make it, but it may not be true. We're at no level of knowledge to discern where the universe came from. Even if we agreed that there was a Big Bang, that doesn't mean that what preceeded it was nothingness, even if we could agree on what nothingness is, which we probably can't. Now, if we can just move on from the trival 8~)
I think we are in complete agreement. I think it is intellectually stimulating to ponder these questions, but without the arrogance to presume I have the corner on the truth.
Another point of complete agreement.
The explanation is simplicity itself: There is no evidence for the existence of any divinity. If I'm wrong, you can easily deomonstrate this by producing the evidence.
Second: The claim that "divinities explain nothing at all" is obviously false. For example, if a Creator exists, then we can explain the existence of His creation.
"If a creator exists ..." Well, that's something you need to demonstrate, isn't it? Until you do, you haven't explained anything.
I have seen Behe's intellect bashed numerous times on this very forum. There is another fact: Even if evolution were fact, ID is a possibility. If the cause of this universe and all that's in it is the work of ID and science in all it's work overlooks this possibility, overlooks this simply because it not logical, seems to me they're the ones who aren't acting intelligently.
To explore ALL avenues with no set destination is the only way to discover.
It is interesting ot note that some dismiss divinity on one ground, namely, where did God come from? Is this not akin to your charge of dismissing all science becuase of one or two (though in actuallity one could find an almost unlimited supply of inprovable things sciecne will never be able to definately answer) unanswerable questions? You likely diagree, so please explain how the two differ so dramaticaly.
The question about the origin of a deity who is, himself, alleged to be the origin of all things is indeed a philosophical problem, but that's far from the only problem. The biggest issue is the total lack of evidence for the existence of such a creature (or creatures). And when you have zero evidence to support a claim, the claim is literally a non-starter. This is entirely different from a scientific theory which is supported by verifiable evidence. It may be true that a particular theory may not have all the evidence one may desire, and thus one may accept the theory on only a tentative basis, but surely you see the enormous gulf between: (a) being a skeptic regarding a thinly supported scientific proposition; and (b) disregarding a totally unsupported theological doctrine.
Besides the bible? How about we are wired for God? How about the fact that we are built to worship. Everyone on this earth worships something. Whether it's science or religion, or material things. How about the research that shows prayer works. I realize to you this is "comic book" material, however, to many, it is evidence. Archeological evidence to support the bible, personal witnesses, but most of all to the individual, the peace that surpasses all understanding. I could go on, but what I've said already is futile. The logical mind is a blessing and a curse.
I think you understand that the arguments you offer are really not persuasive evidence. If it makes you happy, that's fine. And I haven't found any disadvantage to the logical mind. A non-logical mind, on the other hand, can slow down one's progress.
You should at least study the information available before making bets.
Your words games do not change the facts.
That is a good start because evolution is a finite sequence of non-zero-probablity events.
Having Earth in orbit around Saturn until recent times pretty much hits the jackpot when it comes to a zero-probability event. Besides the fact that Saturn is very far from the Sun's habitability zone that it would be too cold to support life as we know it. Additionally, Saturn is a source of life-zapping radiation which would quickly kill off life as we know it. Finally, for the Earth to be close enough to Saturn for the latter's gravity to reduce the Earth's by the third you've postulated in the past, the tidal forces alone would tear the Earth apart.
It's a good thing you don't lobby for Saturnianism to be taught in schools -- a high school physics student could take it apart in minutes. On the other hand, evolution, that big bugaboo of your existence, is the best theory going to explain life as we know it. It must really stick in your craw that the evidence does nothing but support evolution -- oh, I forgot. You believe there is a Grand Conspiracy to suppress the Real Evidence (you've never quite explained WHY they'd try to suppress evidence that would win them all Nobel Prizes, but then again, conspiracy theories do not need to make sense, do they?).
If by "chance" you mean real causes, then we are on the same page. The problem arises when we say probablistic. For example.. is it probablistic there was not an oxidizing atmosphere? is it probablistic some kind of proteins were in some organic soup? well one needs DNA for proteins. Maybe some Stanley Miller amino acids assembled into a primitive funtional protein. unlikely they all need to be "left-handed" is it probablistic DNA formed, well not without protein. ..is it probablistic some phospholipid bilayer assembled into a cell well (proteins and all) in order for the DNA not to be destoyed by the environment? I am not a biochemist so I do not know the answer to all these probablities but they are pretty high. Nevertheless may science march on to discover orgins I think it is fascinating.
Everything in the classical universe has a cause. But when you go into the realm of the quantum world, things happen without a cause. A number of theories have been put forward that a allow the universe to exist, like a quantum event, without a cause.
The fact that life in this part of the universe uses left handed amino acids and right handed protiens is a matter of chance. In the evolution of life one form took hold and the other did not. There is no reason why life in some other part of the Universe would not be formed using chains which mirror our own. As a matter of fact there is an even probablity that life elsewhere in the universe would form from mirror image carbon chains. (If we were invaded by life made from mirror image carbon changes, we would not have to worry about them eating us. )
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