Skip to comments.Artificial Life Experiments Show How Complex Functions Can Evolve
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."
What really must twist your panties however is that a blue collar guy like me is at a minimum your "intellectual" equal.
Mind you now, they are "special transistors".
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.
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.
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?
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.
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.
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.