Posted on 05/08/2003 10:11:06 AM PDT by Nebullis
Arlington, Va.—If the evolution of complex organisms were a road trip, then the simple country drives are what get you there. And sometimes even potholes along the way are important.
An interdisciplinary team of scientists at Michigan State University and the California Institute of Technology, with the help of powerful computers, has used a kind of artificial life, or ALife, to create a road map detailing the evolution of complex organisms, an old problem in biology.
In an article in the May 8 issue of the international journal Nature, Richard Lenski, Charles Ofria, Robert Pennock, and Christoph Adami report that the path to complex organisms is paved with a long series of simple functions, each unremarkable if viewed in isolation. "This project addresses a fundamental criticism of the theory of evolution, how complex functions arise from mutation and natural selection," said Sam Scheiner, program director in the division of environmental biology at the National Science Foundation (NSF), which funded the research through its Biocomplexity in the Environment initiative. "These simulations will help direct research on living systems and will provide understanding of the origins of biocomplexity."
Some mutations that cause damage in the short term ultimately become a positive force in the genetic pedigree of a complex organism. "The little things, they definitely count," said Lenski of Michigan State, the paper's lead author. "Our work allowed us to see how the most complex functions are built up from simpler and simpler functions. We also saw that some mutations looked like bad events when they happened, but turned out to be really important for the evolution of the population over a long period of time."
In the key phrase, "a long period of time," lies the magic of ALife. Lenski teamed up with Adami, a scientist at Caltech's Jet Propulsion Laboratory and Ofria, a Michigan State computer scientist, to further explore ALife.
Pennock, a Michigan State philosopher, joined the team to study an artificial world inside a computer, a world in which computer programs take the place of living organisms. These computer programs go forth and multiply, they mutate and they adapt by natural selection.
The program, called Avida, is an artificial petri dish in which organisms not only reproduce, but also perform mathematical calculations to obtain rewards. Their reward is more computer time that they can use for making copies of themselves. Avida randomly adds mutations to the copies, thus spurring natural selection and evolution. The research team watched how these "bugs" adapted and evolved in different environments inside their artificial world.
Avida is the biologist's race car - a really souped up one. To watch the evolution of most living organisms would require thousands of years – without blinking. The digital bugs evolve at lightening speed, and they leave tracks for scientists to study.
"The cool thing is that we can trace the line of descent," Lenski said. "Out of a big population of organisms you can work back to see the pivotal mutations that really mattered during the evolutionary history of the population. The human mind can't sort through so much data, but we developed a tool to find these pivotal events."
There are no missing links with this technology.
Evolutionary theory sometimes struggles to explain the most complex features of organisms. Lenski uses the human eye as an example. It's obviously used for seeing, and it has all sorts of parts - like a lens that can be focused at different distances - that make it well suited for that use. But how did something so complicated as the eye come to be?
Since Charles Darwin, biologists have concluded that such features must have arisen through lots of intermediates and, moreover, that these intermediate structures may once have served different functions from what we see today. The crystalline proteins that make up the lens of the eye, for example, are related to those that serve enzymatic functions unrelated to vision. So, the theory goes, evolution borrowed an existing protein and used it for a new function.
"Over time," Lenski said, "an old structure could be tweaked here and there to improve it for its new function, and that's a lot easier than inventing something entirely new."
That's where ALife sheds light.
"Darwinian evolution is a process that doesn't specify exactly how the evolving information is coded," says Adami, who leads the Digital Life Laboratory at Caltech. "It affects DNA and computer code in much the same way, which allows us to study evolution in this electronic medium."
Many computer scientists and engineers are now using processes based on principles of genetics and evolution to solve complex problems, design working robots, and more. Ofria says that "we can then apply these concepts when trying to decide how best to solve computational problems."
"Evolutionary design," says Pennock, "can often solve problems better than we can using our own intelligence."
And a skunk loves her children, so what? She still stinks.
Exactly whom did I insult?
It's a clear demonstration of a poster's integrity, of his character, of his innate worth as a human being. For all to see. That's an accomplishment. Perhaps not the one intended, but there it is.
You compare a member of this forum to a skunk and ask whom you insulted?
My intelligence, for one.
Precisely whom? Again, I ask the question to whom are you referring? I referred to a skunk and only a skunk.(unless you assert that a skunks children are not skunks, hmm you are a Darwinian.).
Mr. "Iaminnocent" I addressed it directly to you. Unlike your hidden sniping.
What's really fascinating - and I admit that this is much more interesting to me, in the bloody-wreck-on-the-side-of-the-road sense, than ignorance about how exponents work or failures to understand middle-school plane geometry - is that this sort of denial really amounts to nothing less than a denial of at least the last 600 years or so of Western rationalism. A denial of a rationalism which has always been predicated on the assumption that the universe was a rational place, put together by a rational God, and that therefore you could rationally understand the world around you by modeling some aspect of it, even if the models were imperfect and incomplete representations of reality. The difference between Leonardo's models and computer simulations of everything from evolution to spaceflight to oil exploration is merely a difference of degree, not a difference of kind - the only difference is in the sophistication of the models. One wonders if denying evolution is really worth the price, if that price is simultaneously denying one of the core concepts of Western scientific and philosophical thought. I'm almost afraid to ask what sort of mysticism is proposed as an alternative...
And there was infused in that brain such grace from God, and a power of expression in such sublime accord with the intellect and memory that served it, and he knew so well how to express his conceptions by draughtmanship, that he vanquished with his discourse, and confuted with his reasoning, every valiant wit. And he was continually making models and designs to show men how to remove mountains with ease, and how to bore them in order to pass from one level to another; and by means of levers, windlasses, and screws, he showed the way to raise and draw great weights, together with methods for emptying harbours, and pumps for removing water from low places, things which his brain never ceased from devising.- Giorgio Vasari, Life of Leonardo da Vinci (1550)
No, we insult you because you make stupid statements, Mr. "1720 is a really big number." We insult you because you post before you think. We insult you because we know that 30 seconds on Google would save you hours of embarrasment, but you never quite figure that out. And finally, we insult you because you start out as a blank slate on every one of these threads; you make the same tired, stupid, already-refuted arguments that the other creationists have abandoned (except for the one or two newbies to these threads, and they quickly either disappear or update their repetoire). You don't learn. Everyone of us, creationist or evolutionist, has expanded our knowledge via these threads -- except for you. You haven't figured out that you don't "win" debates by being obtuse, by posting the same tired crap over and over again until the opposition just ignores you. You win by presenting the better argument. Unfortunately, you are so far behind the power curve when it comes to this that you are forced to rely on the former method; you have nothing new or interesting (except as entertainment value) to add to these discourses. We now only read your posts to find the bloopers, as that is becoming something of a sport on the threads you post upon. And, fortunately, you seldom fail to deliver.
So, go on thinking you're winning. Hubris brings out the idiot in you. Eventually, however, your one or two die-hard fans will even start denying you speak for the creationist side.
No need to wonder. If that alternative should come to pass, you and I will be among the first to be slaughtered. Or maybe we'll go in the second or third wave of purification, because there are far more prominent thinkers out there than you and I. It will then be the victorious creationists who will have to live, somehow, in the hell-on-earth that will inevitably result from their ceaseless war on reason.
[To anyone who's wondering ... yeah, I'm talking about you.]
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