The Genetic On-Off Switch

Author: Stephen Caesar
Subject: Chemistry/Biochemistry
Date: 06/21/2006

Many times in previous installations of this column I have referred to the genetic on-off switch, an amazing creation pre-programmed into the genetic code of all living things which, when triggered by external environmental stimuli, causes sudden changes in the individual creature. These changes are sometimes so radical that scientists have mistakenly identified them as examples of evolution via natural selection and survival of the fittest.

These on/off switches are mysterious proteins known as transcription factors, and scientific research has shown that these proteins are an integral, pre-set part of the genome, the genetic structure of every living being. According to Dr. Martha Bulyk, who is investigating the phenomenon of genetic on/off switches, “We get such complex life forms and processes and all the instructions are included in the genome somehow”  (Powell 2005: 3).

Bulyk, assistant professor of medicine, pathology, health sciences, and technology at Harvard Medical School, is a pioneer in the use of microarray technology in the scientific analysis of transcription factors. Her most recent work in this field, published in the December 2004 issue of the journal Nature Genetics, earned her recognition from the Massachusetts Institute of Technology’s Technology Review magazine, which listed her among the top 35 technology innovators under age 35 (Ibid.).

Science has known for a long time now that the blueprint of life is contained in DNA, which consists of long, double-stranded helical molecules in the nucleus of every cell in every living creature on Earth. The DNA helix itself is comprised of a series of base pairs, the order of which determines every single physical aspect of any living being. The DNA is put into action through a process known as transcription, by which a special enzyme breaks apart the DNA helix, reads the genetic code pre-programmed into the blueprint of every living creature, and then creates an RNA molecule that in turn carries that code to another location in the cell to be translated into action. Proteins that bind to specific DNA regulatory elements regulate this transaction process. These regulatory proteins are Bulyk’s transcription factors (Ibid.).

As has been discussed many times in this column, scientists have witnessed firsthand these transcription factors or “on/off switches” being engaged, usually by external factors such as radical, often catastrophic, environmental changes. The changes in an individual species brought about by the turning on (or off) of these transcription proteins are sometimes so profound that the species in question often appears to transform into a completely new species. However, this is not trans-specific macroevolution via random mutation and consequent survival of the fittest, as Darwin had theorized.

Instead, the on-off switches show all the appearance, as mentioned above, of having been pre-programmed into the blueprint of every living creature on the planet. It is almost as if someone intentionally did this so that all living things would be able to survive and overcome the uncountable disasters, environmental changes, and radical transformations the world would undergo in its long history.


Powell, A. 2005. “Bulyk searches for DNA on-off switches.” Harvard Gazette, Nov. 3.

Stephen Caesar holds his master’s degree in anthropology/archaeology from Harvard. He is a staff member at Associates for Biblical Research and the author of the e-book The Bible Encounters Modern Science, available at

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