Genetic engineering offers a major ethical dilemma -- there are great rewards if genetic engineering becomes a widespread reality, but the dangers are equally great.  In addition, genetic engineering also offers the ability to change the very nature of nature, an environment in which man is already well-suited to live in.  Is it possible that genetic engineering will do more harm than good?

Medicines
        As you have probably already learned, DNA is very versatile because all life on Earth processes it the same way (as far as we know).  Therefore, foreign genes can be implanted in bacteria, instructing the bacteria to produce whatever the inserted gene controls.  In this manner, scientists can "teach" bacteria to produce human or other proteins.  There is a long list of bacteria that have been treated this way, including an e. coli bacteria that produces insulin.  The insulin is less expensive than that removed from cows and pigs, as well as being exactly the same as human insulin.
        The ethical quandary about this process lies in the fact that human genes are being inserted into a bacteria.  I do not know of anyone who stands up for bacterial rights; in fact, everyone who has been sick is rather prejudiced against bacteria.  The problem is the idea that human genes are being put in a non-human organism.  Is there anything special about human genes?  If you consider that human genes are made of the same four bases as bacterial genes, and that they work the same way -- as an instruction manual for the production of a protein, there is less of a dilemma.
        However, many people believe that human genes should not be implanted in other species, because they are special because they are human.  Before you make up your mind, consider the alternative method of production, and consider honestly whether or not you would be willing to recieve medicine from a human gene in a bacteria if it was you who needed it.

Xenotransplantation
        Work has been done on genetically engineering farm animals, too.  While in the future it may provide leaner meat, larger animals, or faster growth, right now the great prospect is xenotransplantation.  Xenotransplantation transplanting organs across species.  Currently, most organ transplants are human to human.  They work well, but the drawback is the rejection medication that must be taken to weaken the immune system so that the body does not destroy the new organ.  This, of course, can lead to illness, a definite drawback.  If organs can be "made to order" in another organism and then transplanted over to the human patient, this can eliminate the need for rejection medication and the succeptibility to illness.
        The best prospect for xenotransplantaton of vital organs is the pig.  The pig is one of the closest genetic matches to humans, closer even than monkeys and apes.  With a little genetic alteration, pigs can hopefully produce organs that the human immune system will not reject, producing the desired effect.  Unfortunately, the pig is the loser in this arrangement.
        While on the surface this may seem barbarous, consider the concept: a human is taking something from the animal to extend his own life.  The basic principle is not all that different from eating.  If xenotransplantation still seems cruel, perhaps the world needs to re-evaluate itself and turn vegetarian, eliminating the need to raise animals for the sole purpose of death for man's benefit.

Custom-made Organisms
        Current technology and a great deal of experimentation may allow for custom-made organisms to be produced.  These may range from a bacteria that cleans up oil spills to a monkey with gills and a higher intelligence level.  Everyone seems to agree that we should not pursue these advances just for the fun of it, so the question becomes, are we so inconvenienced by a problem that we need to create a new life form to fix it for us?

Core Issue
        The core issue behind the ethics of genetic engineering is as follows.  Is it morally right to change the nature of life on Earth to suit man's desires better?  The answer to this question depends on man's position on Earth.  If we are truly superior to the animals and accountable to no one, is there a real question of whether it is wrong?  If we are not fundamentally different, do we have a right to meddle with evolution?  If we are accountable to God for our actions, should we risk insulting His creation by trying to do it better?