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Artificial Life Experiments Show How Complex Functions Can Evolve
NSF ^ | May 8, 2003 | Staff

Posted on 05/08/2003 10:11:06 AM PDT by Nebullis

Artificial Life Experiments Show How Complex Functions Can Evolve

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."


TOPICS: Culture/Society; Miscellaneous; News/Current Events
KEYWORDS: ai; crevolist
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To: f.Christian
400?
401 posted on 05/08/2003 2:49:14 PM PDT by Lurking Libertarian (Non sub homine, sed sub Deo et lege)
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To: CobaltBlue
Because what is being claimed about the Earth is pretty nonsensical. It's like saying that my coffee cup will change into a coke bottle if I leave it alone for long enough.
402 posted on 05/08/2003 2:49:23 PM PDT by AmericanAge
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To: AmericanAge
Penicillin is a creature. Why didn't it adapt, too?

Because the penicillium mold doesn't care about the bacteria that kill us. Why should it?

OTOH, the bacteria that kill us needed to adapt to our new weapon to survive. Uncounted maladapted trillions died. The few mutants that were penicillin resistant took their place.

403 posted on 05/08/2003 2:49:54 PM PDT by null and void
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To: AmericanAge
Because what is being claimed about the Earth is pretty nonsensical. It's like saying that my coffee cup will change into a coke bottle if I leave it alone for long enough.

Does your coffee cup regularly give birth to little demi-tasse cups? If not, you might begin to think about why your analogy is flawed.

404 posted on 05/08/2003 2:50:53 PM PDT by Lurking Libertarian (Non sub homine, sed sub Deo et lege)
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To: Lurking Libertarian
>>Critical thinking placemarker.<

You wish.;^)

Somehow, I have a feeling there won't be any place to put one, and eventually this thread will get pulled after people start rolling in the dirt biting each others' ears off.
405 posted on 05/08/2003 2:51:49 PM PDT by CobaltBlue
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To: CobaltBlue
Scientific American, a few months ago...
406 posted on 05/08/2003 2:52:03 PM PDT by null and void
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To: Lurking Libertarian
My coffee cups do.
407 posted on 05/08/2003 2:52:18 PM PDT by Grando Calrissian
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To: null and void
If it didn't care, why did it kill them in the first place, if things evolve towards whatever suits them best? That would be wasted efforts on the Penicillium's fault.
408 posted on 05/08/2003 2:53:52 PM PDT by AmericanAge
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To: Grando Calrissian
Chocalate Sundaes and Boy Bands aren't in the bible. Do they really exist?

They exist. It's the western hemisphere that isn't in the Bible and doesn't exist...

409 posted on 05/08/2003 2:53:52 PM PDT by null and void
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To: Lurking Libertarian
Noone I know has given birth to anything other than what is clearly human. None of the pets I have ever had have likewise given birth outside of their species. So, that doesn't seem to weigh on things.
410 posted on 05/08/2003 2:54:40 PM PDT by AmericanAge
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To: AmericanAge
>> It's like saying that my coffee cup will change into a coke bottle if I leave it alone for long enough.<<

Depends on what your coffee cup is made of. If it's made of glass, and it's recycled, it could be turned into a coke bottle.

But your coffee cup isn't alive, and it doesn't reproduce, so it can't give birth to baby coke bottles.

Coffee cups and coke bottles are probably too distantly related, anyway.
411 posted on 05/08/2003 2:55:14 PM PDT by CobaltBlue
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To: AmericanAge
A rock makes an adequate hammer.
412 posted on 05/08/2003 2:56:25 PM PDT by null and void
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To: Dataman
And unlike you, I never claim to speak for MY side, I speak for myself and myself only.

Nice try at demonization though.

Keep it up, you prove my point about you each and every time you post.

Thanks, I appreciate it.
413 posted on 05/08/2003 2:58:12 PM PDT by Aric2000 (Are you on Grampa Dave's team? I am!! $5 a month is all it takes, come join!!!)
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Placemarker
414 posted on 05/08/2003 2:58:17 PM PDT by Dementon (How do you know you can't swim until you have drowned?)
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To: null and void
Was there really a need to mention it??

Look at all of the other religions of the time. They talk about ocean-rivers, or lands of beasts, or other such things. The bible deliberately doesn't mention what is beyond. God has a plan for humanity; He has made it quite clear that He wants us to learn, to discover. But also in the world, He has placed temptations. False prophets. Deception.

A true believer is not led astray. Are you?
415 posted on 05/08/2003 2:58:20 PM PDT by AmericanAge
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To: null and void
They exist. It's the western hemisphere that isn't in the Bible and doesn't exist...

Sweet. Now I don't have to pay taxes or go to work.

416 posted on 05/08/2003 2:58:45 PM PDT by Grando Calrissian
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To: AmericanAge
More to the point, molds compete with bacteria for food. Penicillim might give the mold a little edge in the comptetion.
417 posted on 05/08/2003 2:58:49 PM PDT by null and void
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To: null and void
Then we're back to where we started. If it *does* help the mold, why didn't it adapt as well?
418 posted on 05/08/2003 2:59:28 PM PDT by AmericanAge
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To: AmericanAge
But also in the world, He has placed temptations. False prophets. Deception.

Would these include dinosaur fossils?

419 posted on 05/08/2003 3:00:22 PM PDT by RightWingNilla
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To: PatrickHenry
This is getting too difficult. It's just one thread after another....AHHHH...
420 posted on 05/08/2003 3:01:03 PM PDT by <1/1,000,000th%
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