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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: Quick1
Didn't you say you had a million example of science changing ... how about a few more !

Is gravity ... the discovery --- man made now (( new science )) ?
901 posted on 05/09/2003 2:32:32 PM PDT by f.Christian (( Marching orders: comfort the afflicted // afflict the comfortable ! ! ))
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To: f.Christian
Of course gravity existed back then, otherwise people would have been flying off the planet. But did we know the reason why ((science)) ? ?
902 posted on 05/09/2003 2:35:55 PM PDT by Quick1
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To: Quick1
Knowing and not knowing it doesn't change science !
903 posted on 05/09/2003 2:38:08 PM PDT by f.Christian (( Marching orders: comfort the afflicted // afflict the comfortable ! ! ))
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To: PatrickHenry
Was that Lisa or Eliza? Sort of a psychoanalysis program. It's still around and if you find it you can program your own responses into it.
904 posted on 05/09/2003 2:38:29 PM PDT by RightWhale (Theorems link concepts; proofs establish links)
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To: f.Christian
Examples of Change in Science Theories:

Phlogiston theory of combustion - based on the faith that something was removed removed from wood to make the resultant ash lighter than the original log. True combustion adds oxygen to the mass of the wood. Research and truth trumped faith.

Indivisible Atomic Model - based on the faith that the atom was indivisible. Research and truth trumped faith.

Creation Science - based on the faith that a book written by pre-medievel religious hucksters knew how things worked. Research and truth trumped this nonsense, too.

905 posted on 05/09/2003 2:38:38 PM PDT by Ten Megaton Solution
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To: Ten Megaton Solution
Ideology -- religion trumps God ?
906 posted on 05/09/2003 2:41:54 PM PDT by f.Christian (( Marching orders: comfort the afflicted // afflict the comfortable ! ! ))
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To: PatrickHenry
flaming lunacy on parade placemarker
907 posted on 05/09/2003 2:42:24 PM PDT by longshadow
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To: RightWhale; whattajoke
Here it is: ELIZA.
908 posted on 05/09/2003 2:43:01 PM PDT by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: longshadow
You got a recall from the kindegarten dept !
909 posted on 05/09/2003 2:43:40 PM PDT by f.Christian (( Marching orders: comfort the afflicted // afflict the comfortable ! ! ))
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To: Dimensio
you're a very persistent troll

Bingo!

It is not at all surprising to find so many Troll feeders in a thread on this topic.

910 posted on 05/09/2003 2:43:58 PM PDT by Jeff Gordon
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To: f.Christian
"religion trumps God" - No. Religion invents God.
911 posted on 05/09/2003 2:44:15 PM PDT by Ten Megaton Solution
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To: longshadow
They said to bring your twin -- buddy !
912 posted on 05/09/2003 2:44:26 PM PDT by f.Christian (( Marching orders: comfort the afflicted // afflict the comfortable ! ! ))
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To: Ten Megaton Solution
Tell Him about it ... someday -- soon (( ask for me to watch the fun )) !
913 posted on 05/09/2003 2:46:22 PM PDT by f.Christian (( Marching orders: comfort the afflicted // afflict the comfortable ! ! ))
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To: f.Christian
Is that the department you're in right now?
914 posted on 05/09/2003 2:46:35 PM PDT by Quick1
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To: Quick1
Talking to you --- YES !
915 posted on 05/09/2003 2:47:41 PM PDT by f.Christian (( Marching orders: comfort the afflicted // afflict the comfortable ! ! ))
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To: f.Christian
>>ask for me to watch the fun<<

What do you suppose God would say or do to someone who believed in evolution all his/her life?

I assume you believe that God would send him or her to Gehenna.

If so, why would you find that entertaining? And, for extra credit, is it Christian to find entertainment in the misfortunes of others?
916 posted on 05/09/2003 2:55:54 PM PDT by CobaltBlue
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To: Quick1
The science you believe in adapts itself to every ignorant mind -- evolution !
917 posted on 05/09/2003 2:56:24 PM PDT by f.Christian (( Marching orders: comfort the afflicted // afflict the comfortable ! ! ))
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To: CobaltBlue
God wills that none shall perish but self will is inviolate !

Fortunately I was reachable !
918 posted on 05/09/2003 3:00:47 PM PDT by f.Christian (( Marching orders: comfort the afflicted // afflict the comfortable ! ! ))
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To: f.Christian
You're evading the question - why do you say you will find it fun to see your fellow creatures be sent to Gehenna?
919 posted on 05/09/2003 3:05:09 PM PDT by CobaltBlue
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To: CobaltBlue
Gehenna placemarker.
920 posted on 05/09/2003 3:06:36 PM PDT by Lurking Libertarian (Non sub homine, sed sub Deo et lege)
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