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.”
We are all basically highly complex machines, and even the most sophisticated and gifted artisans among us have yet to achieve that level of intricate and knowledgeable technology.
The author of the plan is known, the hypothosis you post is most definitely not part of it.
My favorite tune.
Why not?
First things first. If you want to take back the chain of causation beyond a "designer," creator or what you will, be my guest.
It's just that a "still, small voice" is telling me you don't even want to take that first step.
Great! More Christmas cards to send out.
Are they talking about Democrats?
ROFL!!!!!!!!!!!!!!
I believe in the Creator/designer/God. But I also believe in science (though I'm a thorough-going skeptic of standard evolution theory). I look for challenges to my faith, I don't try to run away from them. And you know what? They've pretty consistently wound up confirming or increasing my faith.
If you suggest that the high degree of complexity associated with life, necessitates a designer.
Then wouldn't a designer (who would clearly be even more highly ordered than his creation) need to have been created by an even more complex and ordered designer?
Who created the creator?
I think you're being dismissive, because you have no answer to the question, and don't wish to confront it honestly.
Pardon me if I made the wrong assumption about the premise of your question. But I think my original point stands--we can posit a "creator for the creator" and a "designer for the designer" back in an infinite chain of causation, but until you're willing to make that very first link between life and a designer, it's a moot point.
But you have made the first link between life, and a designer. And in fact, you appear (at least to me) to be suggesting that the complexity of life suggests to you, that a designer is requisite.
And so I'm asking YOU (who have made the link) how you can suggest that a designer is requisite to explain the complexity of life, but that the even greater complexity of the designer himself, doesn't require a designer?
What is your explanation?
EXACTLY!
[alloysteel]We are all basically highly complex machines, and even the most sophisticated and gifted artisans among us have yet to achieve that level of intricate and knowledgeable technology.
As Dr. Doom pointed out, think free market. If you look at the history of any modern industry or marketplace or economy, chances are nobody ever sat down & designed it. It evolved, probably haphazardly & unexpectedly, from much simpler beginnings. Yet in some ways an industry or economy is just as amazing in its complexity & efficiency & resilience (what a combination!) as the very best designed individual machines, or most ordinary living organisms.
(Ironically, the only economies I know about that were explicitly designed are the Communist economies. And we know how well they turned out!)
You are stuck in 4 dimensions. If indeed there is a creator, it would be safe to assume He exists outside of space and time. The Big bang indicates there was a "time" when there was no space and time.
You can get a pretty good answer to that question from The Touchstone of LIFE by Werner R. Loewenstein.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.