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."
This is a total repeat of a previous mindlessly oblivious post of yours. What's the matter, cat got our tongue?
Kindly submit your proof of the actual tangible existence of a law of gravity, which does not employ the formulation of humans of said law. The law of gravity and God stand on equal footing, in terms of being, at bottom, manifestations of faith. It's just that our faith in the Law of Gravity has a more reliable predictive index.
And kindly pick your targets with more precision, I am quite obviously not a classical materialist who categorically rejects any but tangible, palpable evidence, nor am I a neo-classic materialist who accepts secondary evidence, but still categorically rejects intangibles; Being stochastic at heart, I don't reject anything categorically, I just assign probabilities, so there is little point in refuting my non-existent materialist position.
This is a high order of twaddle, even for you. SPICE-designed circuits are not a deep mystery, and high freq or not, induced capacitances are not outside their perview. SPICE is a piece-wise linear modeling system, and it is not under heavy assault by doubting circuit design engineers, or philosophers. It has produced thousands of circuits that operate, in general, with noticably, cashably better reliability than unaided designs have produced.
Um...that that still doesn't prove, or even suggest, that God wasn't the ultimate cause of it.
So you claim, once again, without the slightest hint of sensible evidence for your absurd contention that it all started with prokariotes. When you come around to at least acknowledging that I've made an argument otherwise, we can continue this conversation, until then, you will, of course, repeat your tiresome nonsensical claim over and over, hoping to make your case by wearing out your deponents patience.
I suggest you think about this very carefully. What's being asserted is not that evolution doesn't take place, but that variation is constrained by previously unnoticed physical constraints. The underlying message is that "chance" deals with fewer potential outcomes. This undercuts the argument that evolution is impossibly improbable.
No it doesn't. It only demonstrates that humans have a marked preference for simplifying approximations of some gross behaviors which, to modern physicists, are simply stochastic tendencies in a random sea due to mean distributions with marked central tendencies--much as one would sensibly view the "random" nature of natural selection--if one were actually interested in understanding it.
No, to repeat myself yet again, evolution as a contest between discrete meat machines for scarce resources probably produced bacteria with stable DNA packages. Before there were discrete meat machines with stable DNA packages, the story of evolution would have been governed by different constraints.
I have, in the past offered several examples from the literature as to what these rules might have been. If you don't need to sustain discrete bodies in an environment that where resources are constitutionally not scarce then evolution will not be primarily contrained by failure, it will be constrained by, perhaps, the capacity for retention of viable form. God need not constrain herself to punishing failure, it would work just as well to reward endurance.
Your Ad Hominem is noted. Despite the fact we are not discussing "SPICE-designed" circuits, the "genetic programming" circuit is described as a "mystery". . It's also complex enough that no one's figured out how it works yet.
Again we are not talking of "SPICE-designed" circuits, but we are talking of circuits analyzed using SPICE. They may even be circuits designed using SPICE, but they are not "SPICE-designed".
I did. You are demonstrating that I was correct when I described the statement, among others, as provocative.
Mr bligh needed to have his 30 sec rebuttal --- then flogged --- keel hauled and cut loose with all his sympathizers in the year 1798. Fletcher Christian was a softie -- englishman !
Of course they are. Humans don't lay out the physical topography, and humans don't specify the netlists that drive the founderies or the layout factories. There is an entire industry dedicated to supplementing spice to translate it into circuits off the assembly line.
replacing the human input to spice at the highest level of the design process by replacing the design GUI with the output of another program is what we are addressing here, and, quite clearly, it has been done successfully, even if the resultant circuit were substantially lamer than what humans have produced, so long as it did the job.
We're talking about piece-wise linear approximations of linear algebraic representations of circuit elements. Of course they are "mysterious" in the sense that they are non-linear, but that doesn't prevent us from chatting like this using circuits of equal or greater "mystery".
You can declare all you want, but that does not make it so.
Trollish Behavior #1: Of course my declaration doesn't make it so, Troll. You're squirming. Your dishonesty and behavior is what makes it so. Stop squirming.
We are discussing other declarations of yours that are still hanging.
Trollish Behavior #2: You earlier declared that you weren't going to accept my statements because you hadn't seen a "chart" or "numbers" demonstrating the superiority of the new circuit. Now that they've been given to you, and they do indeed support my statements, you simply retreat to repeatedly (and emptily) stamping your feet and repeating that my statements "are still hanging". No, you got the exact proof you asked for, and now you refuse to accept it. Stop squirming, Troll.
You made specific statements concerning specific circuits. I asked for the evidence backing those specific statements. They are still not backed up despite your red herring.
Trollish Behavior #3: There you go again. Stop squirming, Troll.
[What part of "appear" was unclear to you? I clearly labeled it as speculation, not a "conclusion", you goof.]
If it is speculation then it is not evidence of anything.
Trollish Behavior #4: I never claimed that it was, Troll. Stop playing word games.
You used it as an argument for the fact that the circuit in the paper is not the circuit in SciAm.
Trollish Behavior #5: I didn't use it as an "argument", silly, I offered it as a plainly labeled speculative explanation. Stop playing games, Troll.
You now say you didn't mean anything by it. So be it.
Trollish Behavior #6: I said nothing of the sort, Troll. I meant something by it, just not the twisted "conclusion" you tried to put into my mouth. Stop playing games, Troll.
[which is not invalidated by your red herring about the failure of experimental craft performing never-before-attempted maneuvers millions of miles from assistance.]
Calling my valid statement, which demonstrates that simulations fail, a red herring does not make it so.
Trollish Behavior #7: I never said that my labeling it was what made it a red herring, Troll. I said that your invalid comparison of the failure of a complex mechanical device millions of miles from Earth was a trollish attempt to falsely denigrate the fact that mathematical circuit analysis was a technique of known accuracy and reliability. Stop playing games, Troll.
More importantly the Mars probes failed because the simulations did not take into account different units being used by one team and, in another case, failed to consider the transient response of a hall effect proximity detector on the software that shuts off the engines.
Trollish Behavior #8: None of which is an issue in circuit analysis, Troll. Stop playing games in an attempt to divert the issue from the topic at hand.
I know that you can use a transistor as a diode in a pinch. After all, it "consists" of back-to-back diodes in a sense.
Trollish Behavior #9: Not only "in a sense", Troll, but in actuality. Stop squirming, Troll.
I also know that there exists parasitic capacitance in bipolar junction transistors and that unnecessary transistors floating around will affect circuit performance at high frequencies due to this characteristic.
Trollish Behavior #10: That's a nice speech, but you have failed to in any way demonstrate that the circuit in question rises to the level of having "unnecessary transistors floating around" (ooh, nicely specific, *cough*) to the point where it will "affect circuit performance" (another marvelously vague claim) at "high frequencies" (*how* high?) enough that it will, you vaguely imply, defeat the performance claimed by the authors. Stop playing word games, Troll. Demonstrate your implication, or admit you're just waving your hands. In your own words, this implication (it doesn't even rise to the level of a "claim") is still "hanging".
[Ok, fine, Mr. Wizard, please explain to us how a transistor wired in such a manner *differs* in behavior from a diode]
See parasitic capacitance above.
Trollish Behavior #11: See above rebuttal, Troll. Quantify it, if you can, and actually show that it's more than just a red herring with a trivial affect upon the outcome in this particular case. Stop playing games, Troll.
[And this has *what* to do with the circuits in question, please? Be specific, this ought to be really amusing. (concerning antennae)]
Its operation at high frequencies.
Trollish Behavior #12: Fails to answer the question, Troll. You have yet to establish that the circuit in question even *has* "unterminated runs", as you imply but don't even attempt to show.
Trollish Behavior #13: *How much* of an effect on its "operation" at "high frequencies" (*how* high), Troll? Stop waving your hands and try to make a specific point, Troll.
In conclusion, your hyperbolic assertions remain hyperbolic assertions.
Trollish Behavior #14: Again, they *have* been supported, Troll, and repeating your false accusations is a cheap attempt at distracting attention from your own unsupported *multiple* "hyperbolic assertions". This is *classic* trollish behavior, Troll.
Andrew, stop trolling please. It's this sort of behavior that makes it clear you know full well you're losing the real discussion, so you keep flying off in all directions trying to lay down a trail of red herrings and distractions and excuses for why the discussion isn't really "over" yet.
I'm sure you can play that game forever, but it doesn't mean you're fooling anyone.
No they are not. One was "designed" using genetic programming. The other was designed by Stefano Cipriani and Anthony A. Takeshian.
Bligh having no charts navigated the launch 3600 nautical miles to safety in 41 days using only a sextant and a pocket watch. Only one man died on the voyage - stoned to death by angry natives on the first island they tried to land on. The launch voyage was a feat of navigation unparalleled to this day. "
After all but two of the fifteen men that settled on Pitcairn had been killed in bloody murders...
Fletcher Christian was a typicel bleeding heart liberal. Many of those following FC just killed each other off, 13 out of 15. Bligh navigated well. Anyway, Charles Laughton was a much better actor than Marlin Brando.
No you didn't. I have shown you that the circuit is not the one we have been talking about. And, in anycase, I do not accept a paper only "assertion" (simulation) no more than I accepted your posted assertions.
The rest of your garbage is not worthy of more than a glance. The SciAm article itself on the original evolved circuit pointed out The evolved circuit is clearly more complicated but also contains redundant parts, such as the purple transistor, that contribute nothing to its functioning.. The mentioned part is clearly unterminated.
Solder 2 diodes back-to-back and see if you get a transistor.
Troll yourself.
You have proven yourself to be a Maroon.
Post Hoc, ergo propter hoc.
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