Why Do Stem Cells Create Such Public Controversy?

Biological development is about history, the history of an individual through time. Historically, the dominant epigenetic tradition has seen the developmental process as an unfolding of potential or in terms of the emergence of new organization that becomes an individual organism over time. The concept of development has included differentiation, growth, and morphogenesis; since the mid-nineteenth century, it has been seen in terms of cell division. Along the way have come explorations of such issues as the extent to which development is driven by hereditary determination rather than flexible regulation in response to changing conditions. Some researchers have focused specifically on examining the capacity for regeneration in response to injury or loss, or on the extent to which parts are self-organizing individually rather than determined segments of a whole. This paper introduces the historical study of development.