You might enjoy this related quote from Jacques Monod - Nobel laureate and considered by many as the "father of molecular biology":

"We call these [mutation] events accidental; we say that they are random occurrences. And since they constitute the /only/ possible source of modifications in the genetic text, itself the /sole /repository of the organism’s hereditary structure, it necessarily follows that chance /alone/ is at the source of every innovation, of all creation in the biosphere." [Monod 1972]

I submit that the software engineering is far from a "chance alone" endeavor.

Grant

Russ Abbott wrote:
See abstract below. The article is open source (http://www.pnas.org/content/107/20/9186.full.pdf+html) if anyone is interested.

The conclusions are

"The^ authors interpret these differences in terms of two design principles.^ The need for cost-effectiveness (or reusability) is central^ in programming, and robustness—that is, resistance to^ breakdown due to failure of a part—is the driving factor^ in biological systems. Evolution, they speculate, goes from^ top to bottom in software, but from bottom to top in biological^ systems."

I'm not sure I believe that either the comparisons or the conclusions are completely valid. But it's an interesting comparison. Software evolves at all levels. But doesn't biology also? Aren't lower level functions perfected after being incorporated into higher level entities? It seems to me that biology is just messier and less well designed. No one refactors biological systems. But it seems like the redundancy produces more robustness.


-- Russ



---------- Forwarded message ----------
From: *Science Editors' Choice* <ale...@info-aaas.org <mailto:ale...@info-aaas.org>>
Date: Thu, Jun 3, 2010 at 12:16 PM
Subject: Science CiteTrack: Editors' Choice: Highlights of the recent literature
To: rabb...@calstatela.edu <mailto:rabb...@calstatela.edu>Systems Biology:





Figure 1
/E. coli/ (left) and^ Linux (right) networks

CREDIT: KOON-KIU YAN AND NITIN BHARDWAJ

^

Yan /et al./ have compared the transcriptional control network^ in the bacterium /Escherichia coli/ to the network depiction (known^ as the call graph) of the Linux kernel, which is the central^ component of a highly popular operating system. Both systems^ feature (i) master regulators (yellow in the graphic), which^ send directions to targets; (ii) middle managers (red), which^ both send and receive orders; and (iii) workhorses (green),^ which are controlled but do not control others. For the bacterium,^ there are lots of workhorses but relatively few regulators at^ the other levels. The Linux call graph is top-heavy or more^ populated at the master regulator and middle-manager levels.^ In other words, a workhorse in the transcriptional network usually^ has only a few supervisors, but in Linux, a workhorse answers^ to a large number of regulators. The authors also contrasted^ evolution in the two systems by looking at the functions that^ persist in 24 versions of the Linux source code relative to^ genes that persist in 200 phylogenetically distinct bacteria.^ For /E. coli/, the workhorses showed the greatest persistence,^ whereas for Linux, there was persistence at all three levels,^ but mostly in the master regulators and middle managers. The^ authors interpret these differences in terms of two design principles.^ The need for cost-effectiveness (or reusability) is central^ in programming, and robustness—that is, resistance to^ breakdown due to failure of a part—is the driving factor^ in biological systems. Evolution, they speculate, goes from^ top to bottom in software, but from bottom to top in biological^ systems.^

/Proc. Natl. Acad. Sci. U.S.A./ *107*, 9186 (2010). [One pixel image]



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