Uncommon Descent Serving The Intelligent Design Community

Fault Tolerance a greater foe to Darwinism than Irreducible Complexity


Irreducibly Complex systems are those systems (man-made or otherwise), where removal of critical core parts results in malfunction.

By way of contrast, fault tolerant systems allow removal of parts or entire sub-systems, yet intended function is still retained. Removable parts or subsystems in fault tolerant architectures are also contrasted with useless parts which serve no purpose. Like spare tires, removable parts in a fault tolerant systems can still serve a purpose even if never used.

From Wiki on Fault Tolerant Intelligent Design:

In engineering, fault-tolerant design is a design that enables a system to continue its intended operation, possibly at a reduced level, rather than failing completely, when some part of the system fails.

A fault tolerant system can be composed of several irreducibly complex systems. For example, the space shuttle has 5 navigation systems each capable of serving as a sufficient navigation system in case of damage or failure of the other 4. Many man-made mission critical systems have fault tolerance, redundancy and margins of safety built in.

Not only do IC architectures pose a problem for Darwinism, but more so do fault-tolerant architectures, especially when a fault tolerant architecture is itself composed of several irreducibly complex subsystems! Selection fails to construct fault tolerance because not only do all the parts of subsystem have to be in place for the subsystem to make sense, the existence of the precursors and even functioning subsystems can come at a metabolic cost, especially the large scale fault tolerant systems, making them a liability with respect to immediate fitness.

By definition, Darwinian selection’s lack of foresight will preclude construction of systems that only have meaning through foresight. Construction of a fault tolerant system requires foresight because with respect to immediate fitness, precursors to subsystems are neutral at best, and a liability at worse.

What evidence do we have for this? First some indirect evidence. Consider blind cave fish. An otherwise good visual system that would be beneficial in certain contexts is lost due to the expediency and lack of foresight of natural selection. Selection has no foresight to realize that one day the blind cave fish might be in an environment where its eyes would be useful. Instead, selection eliminates vision rather than preserving it. If selection destroys existing function, how much more will it fail to construct function in the first place, especially when it is not immediately essential and even disadvantageous with respect to immediate fitness.

Blind cavefish provide an illustration of how selection gets rid of function it does not immediately need, and thus how much more will it fail to have foresight to construct something potentially useful. Blind, mindless watchmakers do not plan for future challenges and opportunities, only MINDs do that…

But do we have some direct evidence for the difficulty of selection creating fault tolerance? From Reductive Evolution:

“Interestingly, some species have the ability to regenerate appendages, while even fairly closely related species do not,” Poss added. “This leads us to believe that during the course of evolution, regeneration is something that has been lost by some species, rather than an ability that has been gained by other species. The key is to find a way to ‘turn on’ this regenerative ability.”

If selection has problems preserving fault tolerance, why should it construct it in the first place?

Based on these considerations, I suggest a testable hypotheses: on average real evolution will slowly degrade fault tolerant systems in biological organisms. This can be tested by observing the accumulation of Single Nucleotide Polymorphisms (SNPS) of systems that are not immediately needed, but functional in certain rare contexts. Zebra fish with regenerative capabilities might be a good candidate for such investigations, but I’m sure there are many other candidates…

I demonstrated the fallacy of survival of the fittest in Death of the Fittest, and that real evolution is where function is lost over time, not gained. Fault tolerance is a greater foe to Darwinism than IC, and can lead to further tests of the death-of-the-fittest hypothesis.

In sum, there are three kinds of parts:

1. parts of Irreducibly Complex systems, removal of any of them results in failure

2. parts of Fault Tolerant systems, removal or malfunction of some of the parts does not result in loss of immediate function but reduces the probability of continued function in presence of continued removal or failure of parts

3. useless parts or even parts that are a liability which serve no purpose for the benefit of the organism which can be removed

[Oddly #3 can also pose a challenge for Darwinism in certain contexts (like non-functional convergences), but maybe more on that in a separate discussion on “useless” design…]

IC poses a challenge for Darwinism, and fault tolerance poses an even greater challenge, particularly if the fault tolerant system is composed of irreducibly complex subsystems.


Michael Behe for putting forward the concept of IC on which the further concept of fault tolerance can be constructed.

Eric, I actually think IC's are a subset of Fault Tolerant systems, like the space shuttle navigation systems composed of 5 IC subsystems. Well, I'm open to amending my views if I'm wrong. Sal scordova
scordova: I'm not sure the title of the OP is accurate. Fault tolerance can be seen as a kind of (a subset of) irreducible complexity. Eric Anderson
I would think that knocking out genes without any visible effect is pretty good proof that they are junk or vestigial.
How can you justify that in light of the several of the examples provided, particularly the minimal genome study that demonstrated exactly the opposite of what you are claiming.
I would humbly suggest that excuses should stop being made and start accepting the evidence.
On the contrary, the burden of proof is on those who claim random chemical soups can spontaneously assemble into molecular machines. Evidence is on the side of ID, and you being a nihilist should have really liked the death-of-the-fittest concept (which is pro-ID by the way)... The irony is that you of all people should see that mindless nature leads to death and extinction, not life. Yet you're the one insisting dead things spontaneously become living. Don't you see the contradiction in your view of things? scordova
JLAfan2001, perhaps you need to think about it more closely. scordova has outlined why Darwinism, essentially by definition, does not account for redundancy and fault tolerance. Also, if you don't see that knocking out some DNA without any visible effect does not prove that the DNA section is junk or vestigial, then you need to think back through the logic. Both design and naturalistic evolution can accommodate some amount of junk DNA or some vestigial organs. There is an important difference of expectation and difference of degree, but that is not completely germane to the thread and has been discussed on other occasions. But Darwinism cannot accommodate foresight or planning for future contingency. The question isn't so much about junk. It is about redundant systems and fault tolerance. And on this point the materialist creation myth is completely impotent. Eric Anderson
This is starting to sound like the arguments that evolutionists are accused of making. No Redundant Junk DNA: Intelligent Design Redundant Junk DNA: Intelligent Design This theory is starting to take the path of unfalsifiablity. I would think that knocking out genes without any visible effect is pretty good proof that they are junk or vestigial. I would humbly suggest that excuses should stop being made and start accepting the evidence. JLAfan2001
Thanks for the kind words Eric. From the link to Airplanes Magnetos Contingency Designs in comment #1 regarding knockout experiments, I hypothetically describe how the "knockout" approach would erroneously conclude redundant systems in airplanes are junk and then relate it to exactly the same faulty reasoning that biologists are sometimes guilty of.
What’s wrong with such logic you ask? Well allow me to clarify. Imagine if one applies this line of reasoning to the architecture of a magneto-fired airplane engine:
We knocked out the left magneto system on Airplane X and determined the airplane flies just as well without it. We knocked out the right magneto system on Airplane Y and determined the airplane flies just as well without it. We conclude therefore from these knockout experiments that neither the left magneto nor the right magneto have any functional significance since the airplanes were clearly fit without them. Magnetos are therefore unneeded vestigial artifacts, junk, and evidence poor design, totally useless to the airplane. Furthermore this is further evidence that airplanes are made by blind watchmakers.
Think I’m kidding, and evolutionary biologists don’t make these kinds of obviously bad inferences? See: Minimal genome should be twice the size, study shows
“Previous attempts to work out the minimal genome have relied on deleting individual genes in order to infer which genes are essential for maintaining life,” said Professor Laurence Hurst from the Department of Biology and Biochemistry at the University of Bath. “This knock out approach misses the fact that there are alternative genetic routes, or pathways, to the production of the same cellular product. When you knock out one gene, the genome can compensate by using an alternative gene. But when you repeat the knock out experiment by deleting the alternative, the genome can revert to the original gene instead. Using the knock-out approach you could infer that both genes are expendable from the genome because there appears to be no deleterious effect in both experiments.”
scordova: Thanks for highlighting again this important issue. One of the great "evidences" advanced for Darwinism over the years is the "junk" concept, whether junk DNA or vestigial organs. Unfortunately, Darwinists essentially never take into account important engineering issues, like redundancy and fault tolerance. A moment's reflection for even the modestly-informed individual is sufficient to realize that for a species to survive and reproduce over thousands or millions of years in changing environments and faced with undefined challenges requires a tremendous amount of fault tolerance. Our electronic devices have huge amounts of fault tolerance built in, and yet, inevitably after a fairly short time we have to pull the plug or hit the off switch and reboot, so to speak. Imagine trying to design a system that is capable of functioning over millions of years without ever having an insurmountable crash. Finally, the DNA knock-out experiments that allegedly show large amounts of non-functional DNA are not particularly convincing because (i) there are thousands of functions in an organism for which we have not yet identified the source of the information for the function (it has to be somewhere in the organism), and (ii) knock-outs typically cannot take into account redundancy and fault tolerance -- particularly over numerous generations and thousands or millions of years. Thus, any claims of having identified unnecessary DNA (or other cellular systems, for that matter) are on very shaky ground. At most, we could say that we haven't yet identified any function for the particular stretch of DNA or the particular cellular system. Eric Anderson
The finance sector maven and great character, Nassim Nicolas Taleb, who wrote The Black Swan, pointed out that the sophisticated technology of our world today is a tremendous liability - pregnant with Black Swans waiting to happen - just because they are so sophisticated. Taleb calls, what you call, 'fault tolerance', 'redundancy', and says it would be much safer and more beneficial for a greater degree of redundancy to be incorporated in all those systems. Axel
personally, I think sexual reproductive systems are an even bigger problem for Darwinian evolution, try is I might in imagining it, I can't see how random mutation and natural selection can get anywhere in making a his and hers.... And the work so well together, fancy that Andre
NOTES: 1.The longer version of this article was posted at UD under: Airplane magnetos, contingency designs, and reasons ID will prevail. Jason Rosenhouse responded by saying "if you can remove a part doesn't that invalidate the claims Irreducible Complexity as being evidence of ID?" No! That would be true if all intelligently designed systems were irreducibly complex, and that is not at all true, because some intelligently-designed systems have function because parts are designed to be removed without interrupting function. And worse some ID architectures have dubious benefit to the organism (consider Mount Rushmore) with respect to reproductive success. 2. On a related note: Mike Gene highlights the view that a lot of evolution is reductive: Reductive Evolution, and biochemist Michael Behe points out the first rule of adaptive evolution is loss of function. 3. Another example like cave fish: Reductive evolution in Streptococcus agalactiae 4. Fault tolerance is related to redundancy and robustness, and there are some fine distinctions in engineering literature between the concepts. Anyone with expertise in these distinctions is especially welcome to comment. scordova

Leave a Reply