It has been decades since Watson and Crick discovered the structure of DNA, and over a decade since the human genome was completely sequenced. In the ensuing years, technology to decode, understand, and change individual genes has grown in leaps and bounds. It is no longer a question of if we can change the very thing that makes us human, but should we. The question of should we rewrite the code of life is a complicated one, especially as it is not really one question but several, each stemming from a different type of possible modification. The most important difference is between somatic modification and germ line modification. Somatic cells make up the majority of the human body, everything from skin and hair to neurons and blood cells. Germ line cells are sperm and eggs and the cells that produce them.

It is no longer a question of if we can change the very thing that makes us human, but should we.

Modification of the somatic cells of an adult human is the least sticky of the moral conundrums that surround this technology. These modifications would only affect the individual that underwent the treatment; their children would carry no trace of these changes so they would not affect the gene pool. The modification procedure might be dangerous to the individual, but so are many other legal procedures performed daily. With proper informed consent and regulation, it is hard to come up with a logical objection. Somatic modification is quite similar to plastic surgery- its results can radically alter an individual in almost any way imaginable, but no matter how many how many nose jobs you have, your children will be born with the same nose you were. Of course nothing comes without a price, and the lessened dangers of somatic modification have a cost too - curing the parent of a deadly genetic disease does not protect their descendants.

Germ line modification, on the other hand, has this power. A multitude of genetic diseases could be wiped from the face of the earth—Sickle Cell, Tay-Sachs, Cystic Fibrosis, Hemophilia, Huntington’s—in a single generation. This type of modification makes permanent changes to the human gene pool, any descendants of a person whose reproductive cells had been modified may carry the changes. This powerful tool has its drawbacks, ranging from introducing a new, accidentally created disease, to the obliteration of ‘inferior’ traits such as brown eyes in favor of blue. This is the territory of designer babies, and it quickly becomes a question of where do we stop. Very few would argue that two hemophiliacs’ choice to have a baby without the disease is a moral one, and not many more that BRCA 1 and 2—genes that cause varying types of cancer—should not be eliminated. Allowing parents to choose the eye color of their baby may cause discomfort, but can it really be called harmful? What about selecting for intelligence, athleticism, musical ability? Perhaps even artificially created traits such as resistance to radiation? Even the most liberal minded would be forced to agree that a line must be drawn, but where? For someone will be making these choices, and much sooner than you think.


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  2. Specific Genetic Disorders. (accessed 10/11/16), part of National Human Genome Research Institute.

  3. Macdonald, F. 10 things you need to know about the UK allowing genetic modification of human embryos. (accessed 10/11/16), part of Science Alert.

  4. About Human Germline Gene Editing. (accessed 10/11/16), part of Center for Genetics and Society.