I'm debating someone on stem cell use. We're trying to stay away from the moral implications (or we'd never get anywhere), and so his argument is 'we don't neem embryo stem cells since adult stem cells work just fine.' Essentially, he says that they can cure diseases (which embryo cells haven't been able to do yet), are pluripotent, etc. Does anyone know any scientific resources to see if he's right?
The sources he's already cited are here:
http://stemcells.nih.gov/info/basics/basics4.asp
http://www.21stcenturysciencetech.com/articles/winter01/stem_cell.html
I think you may want to rewind, and see if you're really avoiding the moral question. He's implying that if adult stem cells fulfil the medical need, that this means we can stop research on embryonic stem cells. Why? Why doesn't it mean we have
two sources?
The logical error here is
false dichotomy, and the unspoken assumption is that only one source could be selected.
Whether adult stem cells pan out or not does not affect the rationale for researching embryonic stem cells.
To directly address his claim, however, observe that even in his own citation from the NIH, part D is a set of unknowns about adult stem cells, and they're quite relevant:
- Are they "leftover" embryonic stem cells, or do they arise in some other way?
- Do adult stem cells normally exhibit plasticity, or do they only transdifferentiate when scientists manipulate them experimentally?
- Is it possible to manipulate adult stem cells to enhance their proliferation so that sufficient tissue for transplants can be produced?
- Does a single type of stem cell exist—possibly in the bone marrow or circulating in the blood—that can generate the cells of any organ or tissue?
These are important questions, and while they're not substantially different than questions about embryonic stem cells, there is much more known about embryonic stem cells (questions #1, #2, and #3 have already been answered wrt embryonic stem cells), and we're a long way from saying they're equivalent. #3 is the key: adult stem cells have only been found in a limited list of tissue types, and their differentiation appears to be limited to this and nearby types. (blood, bone, &c are the same 'tissue type', as opposed to, say, bowel).
In the long run, stem cell research may turn out to be a total dead end, but it's inappropriate to close the door on one direction of research.
