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."
No, it may not be clear who would replace Yogi Berra on the pitching mound. But it would be clear that Yogi does not belong there.
That is a either a lie or insensate raving. I did not call their work nothing. I stated this--
You stated nothing about the operation of anything. All you stated was your opinion. The 17 transistor circuit does exactly what and how? All we have is a statement in a magazine that the circuit performs better than a 9 transistor circuit, both diagrammed in the article. The 9 transistor circuit is actually a modification of the patented circuit which consists of 5 transistors and 4 diodes and no resistors. It has a measured performance on display with the patent. There is no such evidence for the 17 transistor kludge. The specifications are for the circuit to be compact and work to the gigahertz range. There is no evidence that the 17 transistor circuit can achieve those specs.
You are long on words and short on facts. I talked about the patented circuit and the data available to those who would look.
What depresses me is when, having debunked the second law argument about evolution for the fifth or sixth time, as clearly as I can, it gets repeated yet again. And it depresses me that the creationists who know better will never correct their own side. When I've posted something that turned out to be wrong or inaccurate, I've been corrected by evolutionists, most of whom seem to have a concern for the truth. Never seen that on the other side.
Never will. When someone starts out with a garbled pile of nonsense (e.g. creationism) labeled "The Truth!", no thought is required. Anything -- anything at all -- that purports to conflict with it is Evil, and must be oppposed. That's all there is to it. Corrections? Not possible. Debate? Ridiculous.
Isn't it apparent there is a lockout?
You should have some idea, since you know I like Shapiro. But this is turning into what I think. I am not in the business of emulating Darwin. I merely have comments on evidence presented to me. So far on this thread the evidence for the assertions is diaphanous. So I await something of substance.
I'm curious about what that 28 percent lower rate means in real life. Perhaps it means non-churchgoers are already hospitalized and can't attend, or perhaps it means churchgoers engage in fewer risky or unhealthful activities.
Sort of like the reason minivans are among the safest vehicles.
Ah, I see! Churchgoers are less likely to be hospitalized and they don't teach things in church.
Do you now or have you ever believed that the current level of genetic diversity within species is consistent with all living creatures being descended from one or seven pairs of their kind, within historic time?
How's that for a question, Senator?
And I answered you(in a round about way), Why would that be?
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