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."
No it doesn't. It takes a tiny fraction of a penny's worth of electricity, just as I just now said. The DNA->RNA->meat-machine cycle, with it's ultra-expensive need to keep renewing the meat-machine by eating other meat machines might be a recent innovation, with no real relevance to the early beginnings of life.
The switch, as usual. We are not talking about fitness cost in the beginning of life, and the article does not deal with the beginning of life either. We are discussing evolution, the time after the beginning of life. The problem with the beginning of life is not fitness cost, it is the absolute impossibility of arranging some millions of molecules into at least half a million DNA pairs in the exact way necessary to produce a living thing.
As to fitness cost, I already gave it to you in the post you are responding to " However, in real life there is a fitness cost of non-useful organs, DNA, etc. It takes energy, food, etc. to keep such useless things alive so there is definitely a fitness cost." Further you already agreed that even a small fitness differential will result in the more fit organisms overcoming the less fit.
Show me one stinkin' example where I said that.
and argue for life from non-life.
I could equally argue that one-cells, or unisexuals, or prokariotes, are non-life, because they don't look like us, play bridge, or pay taxes. If life ramped up from basic beginnings in constrained, mildly ordered natural environments akin to Conway's game of Life, then your claims about life-vs-non-life are just spurious word-games. At some point, unlifelike automata turned into lifelike automata. Where that supposed barrier is, differs depending on what criteria for "real" life you have arbitrarily chosen.
And, at any rate, life evolving from non-life, at any point, in no manner refutes the notion that God is ultimately responsible for the existence of life. Science can only address proximate causes, not ultimate causes.
...
This life/non-life barrier is an example of thinking that human lexical conveniences are tangible physical things. An excluded middle fallacy pioneered by the creationists in regards to the fossil record. The life/non-life barrier is a human classification game, not a real thing with tangible natural attributes.
So it seems that if you believe in God, it is a powerless one.
Why can't you ever track this argument? Obviously not powerless; how could a powerless God create polio? - evil, cruelly, sadistically evil -- got it?
Regardless, you are just trying to avoid the atheist label by playing games. Your attitude towards religion is completely the same as that of an atheist.
Well, now, an attitude plus $1.50 will buy you a cup of coffee at Starbucks. when it comes to putting labels on people regarding their metaphysical philosophies, it is appropriate to examine their philosophies, not their "attitudes". I obviously am not an athiest, because I obviously don't maintain the fundamental tenate of athiesm--that God categorically does not exist.
And, again, for perhaps the 100th time, you have failed to produce your proof--or even any particularly suggestive evidence--as to why I should think that the beginnings of life could only have been a prokariote being instantly assembled out of organic spare parts.
You mean the switch from an interesting discussion to yet another recitation of the exact same feeble, execrable, canned arguments you recycle endlessly without showing the least sign of even enough rudimentary comprehension and courtesy to prevent your deponents from having to explain the same point again and again and again and again...?
We are not talking about fitness cost in the beginning of life,
We were, in just this previous set of posts, in fact.
and the article does not deal with the beginning of life either.
It most certainly does. As does any Alife experiment. The game of life, like the experiment of this article, ramps us up to Turing machines, from, essentially, a silicon substrate embedded with a regularly ordered matrix of charged transistor storage devices. If you can get to a turing machine, you can get to self-reproducing automata, as the Game of Life demonstrates right in front of your eyes, if you bother to look. If you can do it in silicon, you can certainly do it in sulpher bubbles, or clay silicates, or any of the dozen or so candidates for beginnnings that have been floating around. Once you have enduring self-reproducing automata, it is just a matter of mutating your brains out for millions of years to replace the silicon substrate with something else, just like the early amphibians gave up the ocean for the land, just like the early aerobics gave up on nitrogen for oxygen, just like the bisexual multicellulars gave up sucking nutrients from pond scum for hunting down and killing huge mobile packages of nutrients.
I haven't any idea how this point supports the rest of your argument, but, hey, what's new?
The point, if I might be so bold as to suggest sticking to it, was that it isn't necessary to punish failure to have evolutionary changes take place. It is only necessary to reward success. If evolution's beginnings were not a time of heavy dependance on hunting down your food to survive; if failure does not result in your genome losing the meat machinery in your possession to some other genome that's eaten you; then failure is not significant to evolution at this stage of the game.
What's important, I boldly aver, having just thought of it, is the ability to evolve as fast as possible, without stretching yourself so thin you discorporate.
Read, before you criticize. If you'd done that, you'd note the many times I stated that theories are NOT PROVEN, rather the opponent provides evidence of the theory's falsity.
That being said, yet once again, no one has falsified the following theory;
There is no God.
The falsification is simple, yet never has it been done. Haul your god out of his hiding place and put him on display.
Right. I do not wish to discuss it, because it is only relevant to meat machines that have organs and functions to evolve, and a fixed DNA matrix in which to take these single steps to which you refer. If the thesis is that the process of evolution preceeded DNA and meat machines, than arguments apropos to the requirements and behaviors of DNA and meat machines, are--try to follow me now--utterly irrelevant.
Another thought occured to me. I seem to recall that persons having pets live longer than those that do not. It must have been a dyslexic God owner that conducted that study.
Matter cannot reason and not even the most ardent materialists argue that living things can will themselves into a new species so this argument is absolute nonsense.
In what manner is this a relevant response to the extract quoted?
Why, of course it has simple material explanations. One church goer says to another "You look peaked, Bob, you should cut back on the free drinks at the casino", or "Our priest has been caught sneaking a little boy again, so the church moved him to stop a lynching", or "The TB Joe caught from the random bum he slept with last summer is amenable to anti-biotics after all, could someone volunteer to help him go shopping?"
All such expression of the social instinct man has evolved tend to prolong the lives of the group that practices them, hence re-inforcing the gregarious instinct in future generations.
One should blow a loud trumpet and carry a wind up mouse at all times.
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