Should Scientists Continue to Use Embryonic Stem Cells for Research?
Background:
Embryonic stem cells (ESCs) are stem cells derived from the undifferentiated inner mass cells of a human embryo. Embryonic stem cells are pluripotent,meaning they are able to grow (differentiate) into all derivatives of the three primary germ layers: ectoderm, endoderm and mesoderm. Patrick Lee, of The New Atlantis, believes, "These claims have been repeated by policymakers, scientists, and bioethicists alike, yet they fly in the face of embryological evidence. Seeing why will put the embryo research debate on a more solid biological footing" (1). This topic has been brought up many times due to the claims of ethicists and their views on embryonic stem cell research. Bryan Davies, the author of "Stem Cell Laws", explains, "The efforts to regulate stem cell research and bio technical applications legally is an excellent example of the interplay between private property and free-market sensibilities and the public interest that encourages the best possible scientific and medical research" (1). Using stem cells for medical and scientific research is juggling between being ethical and unethical. Bryan Davies also claims, "Human stem cells are universally recognized as a remarkable scientific resource. Human understanding of genetics has expanded exponentially from the early 1950's, as the research conducted to solve the mysteries of DNA molecular function succeeded in providing science with a foundation from which a multitude of bio technical applications have been developed. Stem cell research remains a vibrant and vital research subject for molecular biologists, geneticists, and medical scientists" (1). Stem cells have been used in many scientific discoveries and has helped the field of science grow as a whole. Stem cells have the potential to develop into many different cell types in the body during early growth and repair. Davies explains, "The timeline that defines the history of stem cell research commences with the first experiments concerning human cell division conducted in the mid-nineteenth century" (1). Stem cell research started back in the 1900's before any of the controversy came about. Also without the stem cell research we wouldn't be as advanced as we are today in the medical and scientific fields. Barack Obama and Bryan Davies, the authors of "Stem Cell Laws" state, "By 1900 scientists had determined that some classes of cells (such as the hematopoietic cells found in bone marrow) were capable of producing other cells. These cells became known as stem cells, and three stem cell classifications were determined from their respective cell division characteristics" (1). When scientists discovered these cells, they were classified by their cell division characteristics. Obama and Davies also explain, "Totipotent stem cells are known as master cells produced in early human embryo development. These cells have the capacity to divide to produce a complete organism" (1). This group of stem cells are very important and as well as the question concerning ethics comes into play. These are the most versatile of the stem cell types. When a sperm cell and an egg cell unite, they form a one-celled fertilized egg. This cell is totipotent, meaning it has the potential to give rise to any and all human cells, such as brain, liver, blood or heart cells. It can even give rise to an entire functional organism. The first few cell divisions in embryonic development produce more totipotent cells. After four days of embryonic cell division, the cells begin to specialize into pluripotent stem cells. Davies and Obama observe, "Pluripotent stem cells are produced within the blastocyst: these cells are capable of forming any cellular structure within the body. Fetal tissue, adult stem cells, and cord blood are the three sources of multipotent stem cells" (1). These types of cells are found when the embryo is going through the blastocyst stage and are also multipotent stem cells. These cells are like totipotent stem cells in that they can give rise to all tissue types. Unlike totipotent stem cells, however, they cannot give rise to an entire organism. On the fourth day of development, the embryo forms into two layers, an an outer layer which will become the placenta, and an inner mass which will form the tissues of the developing human body. These inner cells, though they can form nearly any human tissue, cannot do so without the outer layer; so are not totipotent, but pluripotent. As these pluripotent stem cells continue to divide, they begin to specialize further.
In support of continuing stem cell research:
Thesis Statement: |
Against continuing stem cell research:
|
Although many people feel it is unethical to use embryonic stem cells, researchers have shown how effective and useful the stem cells are for the scientific and medical fields.