Genetic Engineering as the End of Human Evolution?

The Story of Evolution, Spring 2005
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Genetic Engineering as the End of Human Evolution?

Tonda Shimbo

In order to have any evolution of a species whatsoever, there must be some sort of mutation. Granted, the majority of mutations attempted by a species fail miserably and the individual plant/animal will not survive, but without mutation, the gene pool is limited – stagnant even, and when the gene pool is stagnant,, there is less chance for survival, and evolution essentially stops (Mayr, (1)).

With that in mind, and the entirety of evolutionary processes, what are we humans doing in the field of genetic modifying medicine? Gene therapy may help a lot of people live out healthier, happier lives (Anderson, (2)), but is this helping evolution? Hurting it? Will our supposed health happiness in the present bring suffering and death for the future of our species? It is a difficult idea even to wrap one's mind around. Of course we want to help our brethren to feel less pain – to use gene and small molecule therapy (see Anderson, 3rd paragraph for definitions) to take away 'genetic diseases' just as one would use Tylenol to take away a headache or a fever – it is the compassionate, humane thing to do. But where do we draw the line between that and the facts of life – death (even young death), diversity in the gene pool (including mutations – attractive or not), etc.?

Reproductive medicine has raised a lot of bio-ethical questions over the past forty or fifty years. From birth-control to Roe v. Wade to test-tube babies to choosing the sex and other genetic traits of one's child (Caplan & McGee, (3)), many wonder where we are going with all of these technological advances in medicine. Are we perhaps becoming too smart for our own good? Recently a 66-year-old woman gave birth to a child in Romania with much help from her doctor as she was too old to create her own eggs – an egg was fertilized and then placed into her uterus (Caplan, (4)). She will be eighty when her daughter enters high school. This may be pushing the question too far towards the bio-ethical standpoint, but nevertheless, where do we draw the line in reproductive medicine? Do we allow, a hundred years - or maybe even decades – from now parents to essentially create their own children by choosing eye color, hair color, intelligence and strength through the simple selection and rejection of genes? From an evolutionary standpoint, this process could alter – even stop completely – the process of human evolution, for it would disallow mutations in pursuit of the 'perfect' child.

Residing in Germany is a four year old boy who was born with a genetic mutation that prohibits production of myostatin (a protein which limits muscle growth), and thereby can hold 7lb. weights in his hands with arms straight out (The AP, (5)). His mother, a former professional sprinter, had one copy of the gene mutated, while both of his are such. This mutation could be a very good addition to the human gene pool. It would allow the human species to; very slowly (as evolution always works very slowly) become a stronger species, which would aid our survival. But then, after chance and natural selection take their course, no one could ever predict whether it would be the gene to survive. Yet, without mutation, the gene pool is limited, and thus the species has a lesser chance of surviving. Many would argue that in our extensive and expanding research on the human genome, one could in effect allow for the strengthening of the species in locating and manually mutating the genes which controlled production of myostatin, and any other factors. However, I would dare to claim that the practice would still limit variation (the key to evolution, along with mutation) in that it would disallow any new mutations from occurring. If a doctor or scientist noticed an oddity in the development of an embryo, he or she would more than likely abort the process and start over again, for fear of the child developing with some horrid and unknown genetic disease. The problem is just that – if it's unknown, we can't be sure that it will end up quite so tragic as the victims of sickle-cell anemia, muscular dystrophy, or any of the other genetic diseases discovered thus far. We can't be sure that it won't have a profound and everlasting positive effect on the human species as a whole.

What does all of this say to the future of our species? Or, for that matter, to the practice of genetic engineering? Should we change the genes of those suffering from genetic disease? Or should we call it an act of chance and evolution, and allow selection to take its course? I fear that if we find a cure for all diseases, our tiny planet will become overpopulated and though we may be healthy, we'll be cramped, claustrophobic, and quite unhappy. Yet I also don't like the idea of anybody suffering from disease. I almost want to make the claim that disease is the natural way of limiting a population, so that it doesn't get out of hand, and that those who can survive – those whose immune systems are tough enough to handle what gets thrown at them, are biologically and genetically superior (though I understand that a great deal of one's ability to deal with disease has to do with the environment in which he or she resides), and that is the way evolution, nature, and perhaps whatever deity is up there intended it (that is to say, if there was intention at all). Perhaps it is like the tsunami – the world's way of recycling and regenerating itself, and though up close it seems tragic and even catastrophic, in the long run it is the best course to take, and will eventually even itself out in order to produce a more adaptive, efficient species.

References

1) Mayr, Ernst. What Evolution Is. New York, New York: Basic Books, 2001

2)A Cure that may Cost us Ourselves Anderson, Dr. W. French, Newsweek: Jan. 1, 2000

3)Reproductive Medicine Caplan, Arthur L., and McGee, Glenn. Bioethics.net

4)How Old is Too Old to Have a Baby? Caplan, Arthur Ph.D.

5)Genetic Mutation Turns Tot into Superboy The Associated Press

6)Future Direction in Bio-Ethics Caplan, Arthur L., and McGee, Glenn. Bioethics.net