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."
And all this time I thought it meant "skip this post".
No, I assume that the lawyers do not do the designing.
I don't think a lawyer wrote this---
OK, A single mutation makes a nerve cell respond to light.
The ability to detect dark/light allows a critter to duck when a sharow passes over it, very slightly decreasing the odds of getting eaten.
A single mutation increases the number of nerve cells in a patch that sense light.
This slightly improves the ability dodge predators, very slightly decreasing the odds of getting eaten.
A single mutation puts a slight dimple in the patch of nerve cells that sense light.
Now the rim of the patch shadows part of the sensitive area when the sigal is coming from the side. The patch now has some directional sensing ability. once again, this slightly improves the ability dodge predators, very slightly decreasing the odds of getting eaten.
A single mutation magnifys the dimple.
Now the dimple looks like the pit on a pit viper. The pit now good directional sensing ability. In a snake this greatly improves the ability dodge predators and strike prey, a very significant enhancement to survival.
The dimple gets deeper and more spherical, the top surface starts to close down forming a primative pinhole camera. Now the proto eye can image.
If this continues the eye closes off and becomes useless.
BUT an eye with a transparent thin layer of skin covering the pinhole is an improvement as the sensitive surfaces are now protcted from sand and grit getting in and damaging them.
A bulge in the layer makes a primative lens, providing a clearer image
and so on...
Well, golly you learn something new every day.
(An engineer would have just drawn the picture...)
Yes, but the words I wrote were in black. The blue words were from the U.S. Patent number 6,404,245.
P.S. I get lazy when it is obvious I am quoting something, such as a dictionary entry.
You might modify 'Christian' with the adjectives 'most modern'. Manichaean and gnostic Christians had very different ideas about the relationship between God, the devil, good, and evil. The gnostic Gospels and other parts of the New Testament Apocrypha, some parts of which are more ancient than most of the orthodox Gospels, are worth reading. The early Church had a vast diversity of belief about these matters; orthodox Christianity managed to stamp out most of it, although I think there are still small gnostic Christian sects in the Middle East (Persia, perhaps?)
And so does 9.
What part of better performanace equals more market share are you having trouble with???
The incremental cost of 6 more transistors is maybe 1/10¢, the improved performance adds a couple dollars to the sales price, and quadruples the market share.
(The difference between the old price and market share, and the new higher price and increased market share is called profit, BTW)...
I think he is...
sorry.
The design stipulated compact.
I have no doubt you think so, but you are wrong. I just understand that people use words for a reason. Words like compact.
I'm sure that any Freeper practicing engineer will correct me if I'm wrong, but I suspect that most circuits are up and running long before anyone writes a verbal description. That would be done by a technical writer, who might be a lawyer or work under the supervision of a lawyer.
Please provide your evidence for this assertion. I mean the exact performance enhancement across the design stipulations.
I was using the Pat Buchanan definition of white:)
Correct.
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