Friday Quotes: Sound Familiar?
by MikeGeneThese remind me of something. 
Although living systems obey the laws of physics and chemistry, the notion of function or purpose differentiates biology from other natural sciences.
To describe biological functions, we need a vocabulary that contains concepts such as amplification, adaptation, robustness, insulation, error correction and coincidence detection.
A number of the design principles of biological systems are familiar to engineers. Positive feedback loops can drive rapid transitions between two different stable states of a system, and negative feedback loops can maintain an output parameter within a narrow range, despite widely fluctuating input. Coincidence detection systems require two or more events to occur simultaneously in order to activate an output. Amplifiers are built to minimize noise relative to signal, for instance by choosing appropriate time constants for the circuits. Parallel circuits (fail-safe systems) allow an electronic device to survive failures in one of the circuits.
Designs such as these are common in biology.
From molecular to modular cell biology
Leland H. Hartwell, John J. Hopfield, Stanislas Leibler and Andrew W. Murray
HT:Rock
April 25th, 2008 at 12:30 am
Filtering would be an additional analogy, if you consider the selection processes that occur at the cell membrane. But what would be the engineering analog for microtubule behavior? Specifically, their ability to disassemble and relocate?
Comment by AnaxagorasRules — April 25, 2008 @ 12:30 am
April 25th, 2008 at 7:47 am
More quotes.
Comment by Zachriel — April 25, 2008 @ 7:47 am
April 25th, 2008 at 11:45 am
Bravo Zach,
You found some quotes that have the word "evolution" in it.
Please remind me, who exactly are you arguing with on these boards again? Duane Gish?
Comment by Doug — April 25, 2008 @ 11:45 am
April 25th, 2008 at 11:52 am
I didn't present an argument.
The authors made several statements regarding evolution, including that alterations in the structure of gene pools arise due to differential reproductive success.
Comment by Zachriel — April 25, 2008 @ 11:52 am
April 25th, 2008 at 1:04 pm
Duck?
Rabbit?
Duck!
Rabbit!
Duck!!
Rabbit!?!
Duck! Duck! DUCK!
Rabbit, rabbit RABBIT!
Rabbit rabbit… HEY WAIT A MINUTE!
Comment by chunkdz — April 25, 2008 @ 1:04 pm
April 25th, 2008 at 5:04 pm
chunkdz:
Just what I was thinking, chunk. Very good post, btw.
Comment by Bilbo — April 25, 2008 @ 5:04 pm
April 25th, 2008 at 6:26 pm
Hmm. I guess I need to get up to speed on why Bugs Bunny and Daffy Duck are big players in evolution.
Comment by nobody — April 25, 2008 @ 6:26 pm
April 25th, 2008 at 6:32 pm
"We believe that general "˜design principles' "” profoundly shaped by the constraints of evolution "” govern the structure and function of modules."
That sounded familiar (as it might be) rephrased: We believe that general "˜evolution principles' "” profoundly shaped by the constraints of design "” govern the structure and function of modules. Now it sounds more like something a "Front-Loader" might say.
(But they also highlight the problem for ID: "One approach to uncovering biological design principles is to ask what constraints they must obey." ID is not a self-delimiting "theory.")
This sounds familiar too (and I was wondering why no one mentioned it): "Modules may also be related by shared design or functional principles, even if they are not related by descent." (?!)
Comment by Rock — April 25, 2008 @ 6:32 pm
April 25th, 2008 at 9:28 pm
Hi chunkdz,
Very nice. I'd say that comment deserves the Comment of the Week award.
You even bring it to the appropriate end-point:
That also sounds familiar:
Comment by MikeGene — April 25, 2008 @ 9:28 pm
April 25th, 2008 at 9:29 pm
Hi Rock,
Yes, that is also a very juicy point.
Comment by MikeGene — April 25, 2008 @ 9:29 pm
April 27th, 2008 at 5:12 pm
Interesting footnote (if even that):
Herbert Simon had argued that modularity facilitates evolution (design) in 1962 ("The Architecture of Complexity," Proceedings of the American Philosophical Society, Vol. 106. No. 6: 467-482.), with his Tempus et Hora "parable." In that context he cites Homer Jacobson's "speculations" on the speed of evolution. I haven't read Jacobson's paper, so I assume that Simon gets it right: "The essential idea in Jacobson's model is that the expected time required for the system to reach a particular state is inversely proportional to the probability of the state"”hence increases exponentially with the amount of information (negentropy) of the state. Following this line of argument, but not introducing the notion of levels and stable subassemblies [modular design principles], Jacobson arrived at estimates of the time required for evolution so large as to make the event rather improbable. Our analysis carried through in the same way, but with attention to the stable intermediate forms, produces very much smaller estimates."
Oddly enough, Jacobson (apparently unaware of Simon's argument) wrote a retraction, obviously ! But in his retraction Jacobson does not correct himself, but compounds the error with gibberish!
http://www.americanscientist.o...
What I find interesting is not the usual "evolutionist vs. cretinist" nonsense, but that reasoning about evolution from a purely design-theoretic perspective may solve significant outstanding problems in evolutionary theory"”such as the related "Haldane's dilemma."
"Retraction this untimely is not normally undertaken, but in this case I request it because of continued irresponsible contemporary use by creationists who have quoted my not merely out-of-context, but incorrect, statements, to support their dubious viewpoint. I am deeply embarrassed to have been the originator of such misstatements, allowing bad science to have come into the purview of those who use it for anti-science ends."
What bullshit!
The argument from the ignorance of design.
Comment by Rock — April 27, 2008 @ 5:12 pm
April 28th, 2008 at 11:11 am
Evolving networks intrinsically exhibit modularity. Older, well-established nodes act as hubs that are modified by newer, more flexible attachments.
Comment by Zachriel — April 28, 2008 @ 11:11 am
April 28th, 2008 at 11:50 am
Rock:
ID may not be self-delimiting but designs themselves can be. A mouse at one end of a maze may have only one pathway to a wedge of cheese. The construction of the maze itself imposes the single pathway constriction and the designer's intent can be inferred by the nature of the design. Although biochemical pathways can be described with precision their origins are clouded in mystery. We can understand tweaking and modifications related to them but are unable to delineate causal pathways to basic designs like genomes which allow for subsequent modifications.
Comment by Bradford — April 28, 2008 @ 11:50 am