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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: AmericanAge
Well said and well mannered. I personally see no conflict between theology and science. In a way, it seems as though they are trying to describe the exact same events in a different language.

BTW, don't blame me, but God created Darwin...
521 posted on 05/08/2003 4:07:43 PM PDT by djf
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To: CobaltBlue
Atheist isn't an insult if you are one. From what you have evidenced so far - by not believing in God's own word - it would appear that you don't believe in God. Or, if you do, you're at least so far removed from the God of Abraham, for which "Pagan" would be a better term. But the words aren't meant as insult; only to describe what your views are, given what you've posted so far.
522 posted on 05/08/2003 4:08:08 PM PDT by AmericanAge
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Comment #523 Removed by Moderator

To: AmericanAge
That just means that their fossils haven't been found elsewhere - probably buried under a huge amount of flood debris. Of course there's tons in Australia - that's where they're currently living. :)

Your ignorance is overwhelming. You may have to live with it, but we don't.

524 posted on 05/08/2003 4:10:21 PM PDT by balrog666 (When in doubt, tell the truth. - Mark Twain)
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To: AmericanAge
Atheist isn't an insult if you are one.

Neither is idiot - and you demonstrate just such behavior.

525 posted on 05/08/2003 4:12:41 PM PDT by balrog666 (When in doubt, tell the truth. - Mark Twain)
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To: AmericanAge
Actually, I think you are the unbeliever. You refuse to believe the entire Word of God, as evidenced in His Creation. You accuse God of creating tricks in order to fool us.

God does not play tricks on us. God wants us to know the truth.
526 posted on 05/08/2003 4:13:16 PM PDT by CobaltBlue
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To: All
Humm? Why did 503 get pulled? Did somebody object to the word "idiot"?
527 posted on 05/08/2003 4:14:49 PM PDT by balrog666 (When in doubt, tell the truth. - Mark Twain)
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Comment #528 Removed by Moderator

To: AmericanAge
>>But also in the world, He has placed temptations. False prophets. Deception.<<

This, by the way, is heresy. In a less enlightened time, you would have been burned at the stake.

Can't remember which heresy, but the belief that God creates evil reminds me of the Manichaean heresy.
529 posted on 05/08/2003 4:21:07 PM PDT by CobaltBlue
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Comment #530 Removed by Moderator

To: balrog666
> Your ignorance is overwhelming. You may have to live
> with it, but we don't.

and

> Neither is idiot - and you demonstrate just such
> behavior.

I forgive you.
531 posted on 05/08/2003 4:25:50 PM PDT by AmericanAge
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To: CobaltBlue
God tests humankind. As evidenced in Job. He chooses to root out the believers and non-believers.
532 posted on 05/08/2003 4:26:43 PM PDT by AmericanAge
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Comment #533 Removed by Moderator

To: js1138
Brilliant use of the mind.
534 posted on 05/08/2003 4:28:22 PM PDT by unspun
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To: CobaltBlue
More accurately, God lets the Devil do it - but it is by God's own will, since He alone is supreme over the world. As in the book of Job.
535 posted on 05/08/2003 4:28:30 PM PDT by AmericanAge
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To: Dataman
The quote "Faith is... the evidence of things not seen" is from Hebrews 11:1. I think it's reasonable to infer Paul meant things that could not be detected by humans. There is abundant experimental evidence for the phenomena you cite.

There are quite credible alternative explanations for the Universe, and one could argue an ineffable, supernatural being is no explanation at all. After all, *why* did God create the universe?

536 posted on 05/08/2003 4:29:23 PM PDT by Right Wing Professor
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To: AmericanAge
I don't recall any false prophets, temptations and deception in the Book of Job. Just adversity.
537 posted on 05/08/2003 4:29:26 PM PDT by CobaltBlue
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To: AmericanAge
>> God lets the Devil do it<<

The Devil has free will, as do we all. The Devil is not working God's will. That's heresy.
538 posted on 05/08/2003 4:30:34 PM PDT by CobaltBlue
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Comment #539 Removed by Moderator

Comment #540 Removed by Moderator


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