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.”
Excellent point. I also love to point out that much of the archeological evidence shows that the Trojan war occurred as described in The Iliad, or that many of the conflicts described in Celtic myths occured as well.
And these single-celled creatures evolved from......?
Do you believe in perpetual motion too?
The statement in question: "On the other hand, divinities are unsupported by evidence and they explain nothing at all."
First: Please support your statement that "divinities are unsupported by 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.
Information scientists are the very ones explaining the mechanics of eveolution. Read The Touchstone of LIFE. I gave a link to it earlier in this thread.
There's no refutation for any of the things noted on that post. You either believe in things like mathematics, probability, and logic, or you believe in evolutionism. Evolutionism isn't compatible with the others.
Billions of years of the molecules organizing themselves by probablistic chance.
A bit like the pot calling the kettle black, hmmm? While you will never come out and say exactly what you believe in (as you probably -- and rightly -- figure you'd be laughed off this forum), from the lengthy amount of time you've been posting on these threads I've come to the conclusion you believe man is the result of genetic tampering by some godlike being(s) at a time when Earth orbited Saturn.
So, who's the idiot? The fellow who studies the fossil record, the genetic evidence, geology, astronomy, chemistry and physics and determines that evolution is the theory which best fits the facts; or is it the fellow who concocts a hairbrained fantasy about aliens breeding people in the orbit of Saturn?
Unsupported by evidence? I could think of a few things...
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.
Spontaneous generation, in other words. I didn't think that was scientific fact. Have we demonstrated that it is possible to get life from non-living matter?
I like your choice of words, "organizing themselves by probablistic chance." I wish my desk could get organized by chance, but I'd be willing to bet that if I came back billions of years later it would still be messy.
Thankyou for the link I'll check it out. My mind is by no means closed, just skeptical of sloppy science; BTW of which creation scientists seem to be the most guilty.
And spontaneous generation has been re-accepted by many scientists, but only as a "one time shot". And you always thought it was just a silly superstition...gotta go, there's flies forming in my supper.
My bet is it would be dust or a rock maybe, but I can guarantee it would not be a living organism. (you need a sludge pond for that, haven't you heard?) ; * )
That would only hurt for a few weeks or a month or two; being an idiot hurts for life. Ask some of the evolutionists about it.
Ouch.
Actually I am a theistic evolutionist, but that's not the reason I'm an idiot. And it only hurts when things happen that I don't like, as when the clearing house for my credit union decides my checking account has been closed and all my checks are returned as "unauthorized". But that's a different thread.
50 posted on 12/18/01 7:09 PM Pacific by OWK
...interesting!
Philosopher RC Sproul quotes Paul Janet in one of his books.."..chance is a word void of sense, invented by our ignorance." He goes on to argue that chance is a nonentity and can therefor do nothing, but rather chance is a term used to decribe mathmatical probability. I agree with him and I assume you, that chance can do nothing and to say it can comes from a lack of understanding what the word means.
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