There is renewed interest in how the different body plans of extant phyla are related. This question has traditionally been addressed by comparisons between vertebrates and Drosophila. Fortunately, there is now increasing emphasis on animals representing other phyla. Pentamerally symmetric echinoderms are a bilaterian metazoan phylum whose members exhibit secondarily derived radial symmetry. Precisely how their radially symmetric body plan originated from a bilaterally symmetric ancestor is unkown, however, two recent papers address this subject. Peterson et al.(1) propose a (...) hypothesis on evolution of the anteroposterior axis in echinoderms, and Arenas-Mena et al.(2) examine expression of five posterior Hox genes during development of the adult sea urchin. BioEssays 23:211–214, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

The issues of the ethics of germ line modification in general and of enhancement by germ line modification in particular have been the subject of hundreds of articles in the bioethical literature. Both because the techniques are far from perfected and because the potential long term side effects are unkown, there is a widespread consensus that germ line modification for enhancement is absolutely unethical and beyond the pale at the present time. The author considers a thought expperiment projecting into (...) the future in which perhaps the safety and reversibility of germ line modification have been clearly demonstrated. Under such circumstances it is contended that the dividing line between treatment and enhancement is difficult and indeed perhaps impossible to maintain. The Jewish tradition is examined and from the various sources cited it would seem that the benefits of certain kinds of genetic enhancements might well outweigh the objections to such manipulations. (shrink)