How Natural is Natural Selection?

In vitro fertilization is gaining popularity among Americans, both couples with fertility problems as well as couples at risk of passing on genetic diseases. According to this article the cost of one cycle IVF is about $12,500. The process of in vitro fertilization involves extracting an egg from the ovaries, and mixing it with sperm extracted from the semen in a laboratory dish. If the egg has been fertilized it is implanted into the woman. In cases where genetics are in question the fertilized embryos undergo preimplantation genetic diagnosis. It is in this phase that humans are about to face a serious ethic dilemma - should parents be allowed choose the genetic make-up of their child. Parents are already able to choose sex which may be an ethical dilemma in itself, but what if a family could also choose whether they want a brunette with blue eyes versus a red-head with brown eyes? Can humans be trusted with so much power in choosing the traits of their own offspring?
Evolution and natural selection seem to have been working their course pretty well for millions of years. Human intervention has led to more than a few problems. While there is no doubt of our contribution to mass extinctions among plants and animals, our choices about humans haven’t been too great either. Currently, China has legislature that each Han family may only have one child. The Chinese culture has shown a preference for male children and since this law was enacted in the late 70s, the population has become mostly male. Should parents in a culture where males are preferred be allowed to choose the sex of their child?
A more interesting topic comes when parents opt to give their child a genetic irregularity. A recent case was raised against a doctor who refused to implant only embryos which expressed dwarfism. A dwarf couple had to get screened for a genetic disease which often accompanies dwarfism. When the couple asked for only dwarf children, the doctor refused based on the premise that the quality of life would be less for the children. The couple defended themselves by saying that they have the right to have a child that looks like them. A similar case dealing with quality of life came with a mother who wanted a deaf child so began looking for a deaf sperm donor. The woman found one and got her wish of having a deaf child (mostly) but then refused to provide the child with any sort of hearing aids.
What some call “the intentional crippling of a child” could just as easily be “the intentional perfecting of a child”. This may not seem bad at first, but what happens when humanity gets to the point that most couples need to screen their embryos before implantation. Is it plausible that choosing the exact genetic makeup of our children could lead to the loss of some traits completely and some sort of species cleansing? Will legislation attempt to correct the loss of traits from an entire species? Perhaps this is just a way to speed evolution but if that is so, how do we justify dictating how natural natural selection is?

Posted by Sarah Kaz