Framing the future: embryonic stem cells, ethics and the emerging era of developmental biology.

Throughout the 20(th) century, advances in biology were accomplished largely through the study of biochemical parts apart from their place within the whole organism. This reductive and analytic approach, which has culminated in the sequencing of the human genome, has now led us back to the study of living beings. When applied to human biology, this inquiry re-opens the most fundamental questions concerning the moral meaning of developing life. The current conflict over ES (embryonic stem) cell research is just the first in a series of difficult controversies that will require us to clearly and precisely define the boundaries of humanity that we seek to defend. Through a careful consideration of the social, political, and scientific foundations of our current debate, we may discern the terms of a possible resolution that can sustain social consensus while opening avenues for scientific advance. Four such proposals were discussed in a May 2005 publication by the President's Council on Bioethics, entitled "Alternative Sources of Pluripotent Stem Cells." One of these methods, altered nuclear transfer, proposes to use the technology of somatic cell nuclear transfer (SCNT), but with a pre-emptive genetic or epigenetic alteration that precludes the integrated and coordinated organization essential for natural embryogenesis. The moral and scientific dimensions of this proposal are discussed as a way forward for embryonic stem cell research as well as a frame for further studies in developmental biology.