According to several recent news articles based on a paper published in Nature Biotechnology,1 scientists have supposedly forced the evolution of an adeno-associated virus (AAV) commonly used in gene therapy.

In gene therapy, AAV can be used to deliver beneficial genes to human cells. The problem with using AAV, though, is that most people have been exposed to the virus at some point in their lives. When AAV is injected for gene-therapy purposes in these people, their immune system attacks and destroys the virus before it has a chance to deliver its therapeutic genes to their cells.

Using “directed evolution,” scientists mutated the viral DNA and selected for those mutants that were able to survive successively higher titers of antibodies against AAV. By repeating this process several times, they found mutant virus strains that withstood large doses of AAV antibodies. These mutant AAV strains therefore could be more beneficial for gene therapy.

How was this done?

The original viral DNA was copied using an error-prone technique that intentionally increased the number of mutations in the DNA. The viruses then produced their “capsids” (a protein structure that surrounds the DNA) and assembled themselves. Viral DNA encodes very few genes, but one or more of these genes codes for the capsid protein(s). The capsid is the target of the immune system. The scientists observed that the mutant virus strains with changes in only 7 amino acids (2 in particular) of the capsid protein were able to evade AAV antibodies.

This discovery actually sounds very familiar to the development of antibiotic resistance in bacteria. Bacteria have variations in proteins commonly targeted by antibiotics. Typically, these variations have arisen by mutation and are only beneficial to the bacteria in the presence of the antibiotic. If the variations do not allow the antibiotic to bind, the bacteria can survive in the presence of the antibiotic. Similarly, some variations in the protein composition of the viral capsid make it better able to avoid antibodies and not be destroyed.

But is this really evolution?

The word evolution can have many definitions, but for most people, it is taken as molecules-to-man evolution over millions of years. The raw material for molecules-to-man evolution is not the varying, already-existing genetic information, but rather the addition of new genetic information. In both cases above, however, no new genetic information was added; instead, the current genetic information was mutated and selected for. This is artificial selection, which operates on the same principles as natural selection. Bottom line: the bacteria remained bacteria and the virus remained a virus.

The word “evolution” is most likely being used by reporters to support the scientists’ (and generally liberal media’s) worldview that is based on their presupposition of evolution/millions of years as fact, rather than as a descriptive term for what was actually observed with the viruses.

As a scientist reading news articles,2 and even the press release3 from the university where the research was performed, I got the distinct impression that readers were being led to a conclusion that a belief in evolution/millions of years was absolutely foundational for this discovery.

Many people have personal experience with the ability of viruses to mutate and evade the immune system. It’s the reason a flu shot is needed every year. Viruses commonly make mistakes when replicating their genetic material, and some of these errors give them the advantage of avoiding the immune system and subsequently causing disease. Scientists simply took this knowledge and artificially sped up the process by causing more mutations to occur, and selected for those viruses that evaded the immune system the best.

Obviously a belief in evolution/millions of years is not needed to initiate or guide this research. Instead the word “evolution” is being used incongruously by the media to reinforce a humanistic worldview that exists in the minds of secular scientists (and much of the public), as opposed to the worldview that the Bible is authoritative on the origin of all living things.

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Footnotes

  1. Maheshri, et al., Directed evolution of adeno-associated virus yields enhanced gene delivery vectors, Nature Biotechnology 24, pp. 198–204, 2006. Back
  2. msnbc.msn.com/id/11221056/ Back
  3. www.berkeley.edu/news/media/releases/2006/02/07_virus.shtml
    www.cchem.berkeley.edu/~schaffer/ Back