I’m sure many of you have seen a reference at one time or another to “The Department of Redundancy Department.” 1
It goes without saying that redundancy is generally not considered to be a “good” thing. If something is redundant it is, of course, unnecessary, useless, unneeded, wasteful, etc. Many skeptics view redundancy in biological systems as evidence that blind, undirected evolutionary processes, and not a Creator, formed living systems.
Redundancy does occur in organisms’ genomes. Evolutionary biologists believe redundant pieces of DNA result from biochemical processes that duplicate parts of the genome.
As a case in point, geneticists have discovered that many of the genes responsible for embryonic development also possess multiple enhancer sequences that each appear to control the gene’s expression in a similar fashion. At first glance, multiple enhancers appear a superfluous feature, but new research shows that this is not so. It seems that multiple enhancers actually impart robustness to the developmental process.2
Researchers studied a gene labeled shavenbaby, which plays a role in the embryonic development of the fruit fly, Drosophila. As part of their work, the investigators generated fruit flies that lacked two secondary enhancer sequences. At optimal growth temperatures, the fruit fly embryos with the missing enhancers developed in a normal manner, for the most part—but at higher and lower temperatures development was disrupted.
The researchers found that they could rescue the altered embryos at extreme temperatures if they added extra pieces of DNA to the embryos. Additionally, the researchers noted the same effect when they deleted the secondary enhancers associated with the developmental gene wingless. These results suggest that redundancy in the enhancer sequences imparts robustness to the development process (particularly when it occurs in non-optimal environments) and can be regarded as an elegant design feature of the Drosophila genome.
Redundancy and the Case for Intelligent Design
Even though redundancy is often viewed in a negative light, sometimes human engineers intentionally design systems with redundant components. On this basis, as I point out in The Cell’s Design, it can be argued that biochemical redundancy is a good design feature.
Redundancy is not incorporated into human designs in an aimless fashion; it’s well-thought out. Because of cost and efficiency concerns, engineers introduce redundant components into their designs judiciously, limiting them to only those parts that are critical for the systems operation.
When engineers incorporate duplicate parts into their designs, they typically engineer the system so that one of the duplicate parts functions as the primary system and the other as a backup. Only the primary system is active, while the backup system is held in reserve, kicking into operation only if the primary system fails. Engineers refer to this type of system as a responsive backup circuit.
And this appears to be how the secondary enhancers operate in the Drosophila genome. Rather than representing the unthinking randomness of evolutionary processes, secondary enhancers provide evidence that life is the product of a Creator’s thoughtful handiwork.
- To order a set of “Department of Redundancy Department” mugs, go here.
- Nicolás Frankel et al., “Phenotypic Robustness Conferred by Apparently Redundant Transcriptional Enhancers,” Nature 466 (July 22, 2010): 490–93.