Wednesday, October 27, 2010

When new questions arise

Seven years ago human society set a milestone in its scientific history – the Human Genome Project had been finished and scientists had mapped and sequenced all the genes encoded by the genome of Homo Sapiens, our own species. The results of this international research, lead in parallel by state- funded international research team and by the private company Celera Genomics have asserted the existence of 20,000 to 25,000 human genes, their genetic markup and their respective functions. Researchers have also created a database of the most common genetic variation that distinguishes one person from another. Inevitably, this knowledge is bound to mark the beginning of new medical treatments; however, its social, political and environmental implications raise new and somewhat unusual questions.

For one, if less expensive, more effective and reliable techniques that sequence the human genome are devised, one’s medical chart would start to include one’s own genetic blueprint. Consequently, we would be able to read our genes and discover the anomalies in our DNA, thus learning which diseases we are predisposed to. With this valuable information, each of us would work at lowering the risk for disease, and similarly, disease treatment could be personalized for every individual. For the time being, this has only been done for Craig Venter, the owner of Celera Genomics, who already had his genome sequenced only to find himself predisposed to Alzheimer's disease, heart disease, and macular degeneration; he has been taking cholesterol-lowering drugs ever since. Additionally, gene therapy could turn from the dream that it is today to reality: in 30 years from now it would be commonplace to replace disease-causing genes with normally functioning ones. In that manner, we would be able to cure and prevent many (if not all) genetic disorders from the most benign ones like colorblindness to the lethal ones like Huntington’s disease. Moreover, genomic research may prove crucial to exploring programmed cell death, which causes aging and uncontrolled cell growth – cancer. Although these scientific breakthroughs would certainly mean saving more lives, the extra weight we would quite consciously and willingly put on nature’s shoulders would be immense. With population of nearly 7 billion, we are already facing major problems such as water deficit, pollution, and climate change. A dramatic increase in human population would disrupt our already precarious environmental balance, exacerbating all problems connected with overpopulation. Furthermore, if we learn to control the mechanisms that regulate cell death and aging, our society would have to limit human lifespan, rather than attempt to extend it.

With so much information on our genomes available to us, a genomic library would surely have to be set. Yet the challenge lies in deciding who, besides medical personnel, would be granted access to our personal genetic information, and to what extent. If, for instance, employers have access to a job applicant’s genome, they might base their hiring decision on the risk of this person to develop certain conditions. Similarly, an insurance company might offer different policies based on various genetic markups. Unless society imposes clear regulation and legislation regarding the usage and access to individual genomic information, carriers of abnormal genes might be stigmatized, and bio-piracy would be unrestrained.

Another tantalizing aspect of genetic research is that we, humans would overtake the role of nature. By replacing abnormal genes with gene therapy we would act directly on natural selection, narrowing down the gene pool and reducing variation. This would work perfectly if environmental factors on Earth were essentially stable; yet, this is not the case. Tremendous variation is hidden in every gene pool, and it can be expressed by selective pressures; in other words, populations are so diverse because some genes that are disadvantageous in one particular set of conditions, could turn out to be quite advantageous if the conditions (the environment) change. Nature has its way of preserving variation in humans with sexual reproduction, heterozygous advantage, random mutation, etc. Severely reducing variation could jeopardize the entire human race in the case of a sudden environmental change when the genes that we find useful and important today would turn to be disadvantageous.

Although important breakthroughs have been made, scientists still strive to understand all the interactions between genes themselves, genes and the non-coding DNA sequences, and finally, genes and the environment. In this respect, the 21st century might even unravel the answer to the everlasting question of nature vs. nurture. Or perhaps, with all the genetic information stored in computerized genomic libraries we will witness the birth of the first synthetic human, whose parent would be the computer itself? One is for sure: these new questions call for scientists across all disciplines to chart the new, unknown territories.

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