Stem cell research is a hot topic; one many debate constantly. The topic has as many proponents as adversaries, and shares approximately the same number of pros as cons. In August 2001, President Bush authorized federal funding for stem cell research because of its promise of possible cures for medical conditions such as Alzheimer's Disease and Parkinson's. The origin of the stem cells, however, is the cause of great debate.
A stem cell can "grow" into virtually any type of cell. It has the ability to adapt, so-to-speak, to its environment. For instance, stem cells may help in the treatment of cancer. Doctors can replace cells damaged from radiation and chemotherapy with healthy stem cells, which then continue generating healthy cells. They can do this anywhere in the body--the liver, brain, heart, lungs, et cetera.
The body has three main sources of stem cells, the first being the adult stem cell. This comes from a person's bone marrow, and though painful to remove, the person is guaranteed the stem cell is a perfect match for their body when it comes to time to treat. The drawback for most adults, however, is that the person may not have enough time to undergo removal of their own stem cell. When it gets to this point, the health issue is typically too pressing and time is of the essence.
Another source is the umbilical cord. Stem cells taken from a baby's cord is a perfect match for the baby in the future, and also for its parents. Doctors remove the cells from the cord during the pregnancy. They are then stored in cryogenic cell banks much the way blood is stored in blood banks. Parents look at this as an insurance policy for their child.
The third, and most controversial source, is an embryo. Most--not all--embryonic stem cells come from donated eggs that are fertilized in vitro in an in vitro fertilization clinic. The donors sign a consent form, knowing full and well their donated eggs are used for research purposes. Adversaries of stem cell research argue it is murder; the embryo is a living organism. Proponents of the research state the embryo has no human features; they believe the research can save lives and cure the incurable illness.