Pundits and politicians argue about stem cell research in a way that seems complicated, but it doesn’t have to be that way. Whenever things get foggy, just find out which kind of stem cell research they’re arguing about.
- With one exception (see #3), embryonic stem cells are harvested from a human being in his or her earliest stages of development, before those cells have had time to specialize. By definition, this requires cutting up the developing human being. This kills him or her without fail, and it’s why most people object to this type of research.
- Adult stem cells are found scattered among mature cells in your tissues or organs. They are very basic cells much like an embryo’s cells, and they can differentiate to yield the major specialized cell types that make up your tissues and organs. The primary roles of adult stem cells in a living organism are to maintain and repair the tissue in which they are found, but they can be coaxed into becoming other types of mature cells. Nobody has any moral objections to research on adult stem cells, and the federal government funds it.
- The only way to collect embryonic stem cells without killing embryos is to use the tissue found in umbilical cords and placentas, which are expelled during childbirth. Very few people know about this source of stem cells, which can eliminate any “need” for embryo destruction.
It’s all about definitions. Once you narrow down the subject, the argument becomes much more straightforward.
I’ve synthesized these definitions from my own work, from the NIH, and from ClearlyExplained.com.