This is part three in a five-part series called "The Limits of Accelerating Returns" that focuses on the limitations of Ray Kurzweil's Law of Accelerating Returns when applied to molecular biology and biomedical technology, including longevity treatments. The other articles in the series are "The Limits of Accelerating Returns," "Biology is not Digital," "Some Rates are Fixed," and "Implications of Fixed Returns."

In his essay called “Making the World a Billion Times Better,” Ray Kurzweil writes, “The approximately 23,000 genes in our cells are basically software programs, and we are making exponential gains in modeling and simulating the information processes that cracking the genome code has unlocked.” The problem is that genes are only roughly analogous to software programs, as I discussed in the previous post in this series, and simulating the information processes of the genome is non-trivial in the extreme.

Let’s take a very simple example of an artificial genome called a “repressilator” that was added to bacteria as a proof-of-concept of synthetic biology and biological simulation. The repressilator’s machinery consists of three genes, each of which turns off one of the other genes. When one of the genes is active, it turns off one of the other genes. Meanwhile, the third gene is in the processing of shutting down the first. When the first gene is turned off, the second one turns on, and stats shutting down the third gene. Thus, there’s a cycle or oscillation to the activation of the genes (the name of the construct is a contraction of “repression” and “oscillation”).

The system also includes a fourth gene that produces a visible signal so that the oscillation can be tracked. This seems like a pretty straightforward system. The scientists who developed it even did a lot of modeling to figure out how to optimize the oscillations before they went to the trouble of building the thing.

But it didn’t work the way they expected.

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28 May 2008 • BioMedTech

Single-Molecule DNA Sequencing: Sequencing a single molecular of DNA is quite a feat. It reduces both the error rate and cost of sequencing. Now a company has sequenced the genome of a bacterium using a single molecular of DNA. The approach is not perfect but could be expanded to allow individual human genomes to be sequenced, which is a key component of the new era of personalized medicine.

Gordon Moore, co-founder of Intel, famously stated that the number of transistors in a computer chip will double every 18 months. This trend has held for the last fifty years and will continue for the next decade. At that point, engineers will start to run into the physical limits of the photolithography methods used to manufacture computer chips. They will no longer be able to squeeze more transistors onto a chip, and Moore’s Law will have run its course. But if we reformulate Moore’s Law to state that computing power will double every 18 months, or even every 24 months, then there’s no end in sight.

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29 February 2008 • InfoTech