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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: balrog666; PatrickHenry
I have alerted the Evilooshun Sleeper Cell. Await embedded instructions within the source code at DU.com.
1,781 posted on 05/21/2003 1:12:57 PM PDT by whattajoke (Gore3000 and the Amazing Technicolor DreamFont... coming to your town soon!)
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To: longshadow
Hey! RAH says it's perfectly all right, as long as I do it in private and wash my hands afterward... No wait, he was talking about writing. Never mind.
1,782 posted on 05/21/2003 1:29:20 PM PDT by Junior (Computers make very fast, very accurate mistakes.)
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To: Ichneumon
Hey Mr Wizard, how many transistors are illustrated below?


1,783 posted on 05/21/2003 1:53:55 PM PDT by jwalsh07
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To: jwalsh07
For what it's worth, I see a bunch of those nasty italian cake-cookie things you get at italian weddings. god, I hate those things.
1,784 posted on 05/21/2003 1:56:42 PM PDT by whattajoke (Gore3000 and the Amazing Technicolor DreamFont... coming to your town soon!)
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To: whattajoke
Well, one thing I'm sure of, your answer will be better than Itchy the Ingineer's.
1,785 posted on 05/21/2003 2:00:01 PM PDT by jwalsh07
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To: Ichneumon
I'll concede two points to you. First of all you are verbose, an indication of being full of crap. And second, you write like William Buckley speaks, sort of nasally.

What really must twist your panties however is that a blue collar guy like me is at a minimum your "intellectual" equal.

:-}

1,786 posted on 05/21/2003 2:06:31 PM PDT by jwalsh07
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To: AndrewC
How about you Andrew, how many transistors do you see in 1783?

Mind you now, they are "special transistors".

1,787 posted on 05/21/2003 2:19:01 PM PDT by jwalsh07
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To: gore3000
G3K: "Lots of water is not an example of self-assembly. Neither are snowflakes which are just the result of freezing of water and perhaps the power of the wind in giving them different shapes. They lack complexity. They are totally due to natural forces, and very simple ones at that."

Even though this argument is only tangentially related to evolution (evolution does not deal with the origins of life, just the process by which life adapts over time to the environment), what about viruses? They can be observed self-assembling in a test tube without any evidence of little angels pushing their little molecules around. Likewise for every single celled organism. We have seen the mechanism of self-assembly. We have never observed a miraculous creation. Which one makes more sense scientifically?

G3K: "The DNA in the simplest organism however, the arrangement of it is not only not due to any natural forces, but it cannot be due to it. Otherwise we would not be able to find all the possible ways in which 3 different bit pairs with 3 possible values (64 in all) appear in the DNA sequences of all species. Such self assembly is totally unknown anywhere in the natural world. For anything even close, one must go and look at humanly designed things."

First, DNA is not an organism. Second, there is no need for anyone to "find all the possible ways" to make a certain sequence to exist in all species. In fact, with evolution you would expect to find common sequences among organisms with common ancestors.

For bookkeeping purposes, we're still waiting for your definition for what passes as self assembly since you've rejected so many examples. And we are still waiting for the reason you claim that all members of a species must evolve together because any genetic difference within the pool will prohibit mating.
1,788 posted on 05/21/2003 2:48:38 PM PDT by freeper4u
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To: freeper4u
Self-assembling placemarker.
1,789 posted on 05/21/2003 4:24:54 PM PDT by Lurking Libertarian (Non sub homine, sed sub Deo et lege)
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To: All
PLACEMARKER (Hee hee.)
1,790 posted on 05/21/2003 5:36:22 PM PDT by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: gore3000
G3K "it takes numerous attempts at changing a species to achieve a single beneficial mutation - even according to evolutionists... To achieve it, it requires numerous individuals to serve as guinea pigs and die trying."

Not necessarily. There's an infinite spectrum of possible effects of mutations that are not immediately beneficial.

G3K: "What is worst, the whole group, in a sexual species has to change together, otherwise the group would be split by becoming sterile to part of the group."

G3K, the next few sentences are fine up to this one. If this were true, you would have to show that all mutations break reproduction. That's simply not true. There are hundreds of breeds of dogs. Even though the significance of the changes between them is huge, most of them can interbreed. If your hypothesis were true, instead of getting a mutt, the offspring would die.

If you consider the node just before two species branch, there should be a range of creatures with different characteristics at different geographic locations, all of whom can technically interbreed. At the time of the branch (it is not a moment, but a period of time), you will see some kind of failure divide the species between those that evolved one set of traits, and those that evolved another. However the populations at both ends of the spectrum can still mate with each other, just not from one end to the other.

As a hypothetical example, you may have a frog that has done particularly well in one region by eating mosquito larvae that has overflowed into a new territory with less mosquitos. The frogs in the first area continue to optimize for eating mosquito larvae and avoiding water preditors while the same frogs in the new region start to optimize for climbing and catching new types of of prey such as crawling insects. At some point, the frogs in the new territory become so different that they cannot mate with frogs back in the old territory, but at that point, there are already two entire populations of frogs who can continue to mate within their own groups who share the same ancestry.
1,791 posted on 05/21/2003 6:23:30 PM PDT by freeper4u
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To: whattajoke
What makes an atheist virulent? Is it a recognized sect of the church of Darwin that we so often hear about?

Are you denying that Gould was an atheist? This is the typical doubletalk garbage from you and your friends. That Gould was an atheist is well known and well documented. Like the Clintonites you attack people for telling the truth because you do not like to hear the truth.

1,792 posted on 05/21/2003 7:14:52 PM PDT by gore3000
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To: jwalsh07
I'll concede two points to you. First of all you are verbose, an indication of being full of crap. And second, you write like William Buckley speaks, sort of nasally. What really must twist your panties however is that a blue collar guy like me is at a minimum your "intellectual" equal.

Wow, you must be unlucky since you went 0 for 3. Or maybe you're just stupid. Gee, which one would I bet one?

In case you didn't get it, that was a rhetorical question.

1,793 posted on 05/21/2003 7:47:46 PM PDT by balrog666 (When in doubt, tell the truth. - Mark Twain)
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To: balrog666
Ah, the court jester speaks and as always plays the fool. Nice to know somethings never change.
1,794 posted on 05/21/2003 7:50:29 PM PDT by jwalsh07
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To: jwalsh07
Nice to know somethings never change.

Ah, yes, that would the your viewpoint of the world from out of your anal sphincter.

1,795 posted on 05/21/2003 7:53:06 PM PDT by balrog666 (When in doubt, tell the truth. - Mark Twain)
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To: balrog666
Ah, yes, that would the your viewpoint of the world from out of your anal sphincter.

Not only a court jester but an anally fixated one at that.

Any opinion on two diodes back to back equalling a transistor?

1,796 posted on 05/21/2003 8:01:25 PM PDT by jwalsh07
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To: whattajoke
Lots of water is not an example of self-assembly. Neither are snowflakes which are just the result of freezing of water and perhaps the power of the wind in giving them different shapes. They lack complexity. They are totally due to natural forces, and very simple ones at that. The DNA in the simplest organism however, the arrangement of it is not only not due to any natural forces, but it cannot be due to it. -me-

Fascinating bit of personal opinion

Excuse me? That water does not self assemble itself into a lake is personal opinion? Your arrogance shows your total dishonesty and idiocy. Only a total fool would think that he can deny obvious facts as above and fool others into believing as he. All the above are created by simple well known forces.

As usual you and your friends dishonestly forget to address the meat of my argument which is (from the post you are supposedly responding to):

The DNA in the simplest organism however, the arrangement of it is not only not due to any natural forces, but it cannot be due to it. Otherwise we would not be able to find all the possible ways in which 3 different bit pairs with 3 possible values (64 in all) appear in the DNA sequences of all species. Such self assembly is totally unknown anywhere in the natural world. For anything even close, one must go and look at humanly designed things.

Let's see you or your friends refute the above.

1,797 posted on 05/21/2003 8:12:46 PM PDT by gore3000
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To: balrog666
I didn't think so.
1,798 posted on 05/21/2003 8:15:03 PM PDT by jwalsh07
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To: PatrickHenry
I expect that he would attempt a campaign to drive his debate opponents from the website.

The slimer gives us another example of his total hypocrisy. It is the evolutionists which EVERY TIME an opponent starts showing that evolution is total bunk that start with the insults. For example, soon after I started posting on this thread (and getting no replies of course as is usual from the evolutionists since they cannot deny the truth but just insult the bearer of it).

I have often challenged you to show a single post from you on this thread which is not an insult. A single post from you discussing the subject at hand. There are none such because you do not discuss, you insult and encourage your friends to do the same and turn threads into shouting matches so that they will be pulled.

1,799 posted on 05/21/2003 8:28:01 PM PDT by gore3000
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To: Junior
They do just what they say: they mark our place in a discussion.

Yup, they mark the place to stop discussing and start insulting. They mark the place to start spamming the thread with irrelevancies. They mark the place to start indulging in personal attacks.

They have nothing to do with discussion. They have everything to do with NOT discussing the topic as you are doing right now.

1,800 posted on 05/21/2003 8:31:33 PM PDT by gore3000
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