First let me say that this has been a fascinating discussion and I wish that I had time to participate in it further. Thank you bioconservative for sharing your views in "enemy territory". I am glad to see that Aubrey, randolfe and others have weighed in on the topic.
Indeed, the human gene pool may be in constant flux, but only within a range, an equilibrium. What is a Darwinian population other than a variation around a mean? There most definitely is the distinct ontological/biological category of ‘species’ and it consists of reproductively isolated populations possessing relatively stable phenotypic/morphological form. A proper reading of Gould (and the paleontological record) would bring one to an understanding that populations do not evolve by ‘constant speedism’, but rather through sudden, abrupt bursts followed by sustained periods of equilibrium. The fact that is often over looked by armchair scientific philosophers is that there is not one, but two options for the trajectory of a species. They either evolve – or THEY DIE OFF.
As a biologist I feel the need to dispute your proposed human gene pool equilibrium as nonsense. That must be the conservative in you talking.
Evolution is an arms race with the gene pool constantly realigning to current conditions. We must not deny this process. We must embrace it and humbly try to understand it to try to fit our Intelligent Design rather than let it continue as a Blind Watchmaker. With our increased understanding this becomes less a choice and more of an obligation. For this is the crux of the matter. We need to face the fact that there is no retreat from evolution. It is happening whether we acknowledge it or not. We can choose to retreat from that realization which I believe might be your choice or we can accept it and see where that knowledge will take us which is the choice that I believe that many on this forum would make.
As for Gould and punctuated equilibrium. Evolution is proportional to selective pressure. Periods of rapid evolution will be obvious in the fossil record so it is easy to prove that they have occurred. Gradual evolution is less obvious from the fossil record and is better studied in the genetic record.
I would ask "Who are you to deny us our choice?. Would it be ethical for Jehovah's Witnesses to prevent others from taking blood transfusions? If you are worried that your dignity will be sullied by the use of stem cells then don't use them. By impeding stem cell research you are denying us our choices. That is paternalistic and by what right do you make that choice. I am sorry but "intrinsic worth" does not convince me and "unforseen consequences" means you had better use your imagination more effectively and come up with foreseeable consequences that are compelling considering the stakes. For splitting hairs on the start of life aside, the real agenda appears to be to impede progress and maintain an imagined "equilibrium" or status quo which is a more difficult goal than biological immortality.
I guess it was inevitable that in discussing therapeutic cloning I would have to at least put forth my fears concerning extensions of the maximal human life span – because, after all, that is one of the unspoken objective of developing these advanced biotechnologies, is it not?
Increasing the human lifespan is, in itself, an augmentation of human capacities. The fitness and stamina of youth combined with the wisdom and knowledge of maturity. How would an up and coming generation stand a chance? It wouldn’t, and this is but one of many objections that can be made against human augmentation. Our human essence is our functional equilibrium as a society.
Again note the synchrony between "equilibrium" and your bioconservative views. Our society is not in an equilibrated state so statements about "functional equilibrium" stick in my craw. Perhaps you could elaborate with specific examples of how you believe we have reached equilibrium.
All the conservative position is advocating is that society take things slowly, and with more caution. The soundness of such an approach is apparent, unless, of course, one allows one’s personal existential angst to cloud their better judgment.
That is one perspective on the conservative position. Another is that it is a knee jerk resistance to change and that will try to obstruct change by any means available but in this case literally millions of lives are depending on these decisions being delayed without a compelling argument. I value life, especially my own there is no angst about it.
I would just like to close with some questions.
What is dignified about a living dynamic intelligent human being being destroyed by death? I do not think that any answer that you can provide will convince me that to die of aging is noble. Talk about a "yuck" factor. My wisdom of repugnance is telling me to avoid dying.
If you believe that abortion is acceptable then would therapeutic cloning be even more acceptable once proof of principle had been established? From what I have gathered from the posts your main opposition at this point was that the sacrifice was being made and was unlikely to produce therapeutic benefit.