This paper began its life as an unpublished technical review citeanalysis of the proposed Open Grid Services Architecture (OGSA) as described in the papers, ``The Physiology of the Grid'' citefoster by Ian Foster, Carl Kesselman, Jeffrey Nick and Steven Tuecke, and ``The Grid Service Specification (Draft 2/15/02) citeogsi'' by Foster, Kesselman, Tuecke and Karl Czajkowski, Jeffrey Frey and Steve Graham. However, much has changed since the publication of the original documents. The architecture has evolved substantially and the vast majority of our initial concerns have been addressed. In this paper we will describe the evolution of the specification from its original form to the current draft of 10/4/02 authored by S. Tuecke, K. Czajkowski, J. Frey, S. Graham, C. Kesselman, and P. Vanderbilt, which is now the central component of the Global Grid Forum Open Grid Service Infrastructure (OGSI) working group which is co-chaired by Steven Tuecke and David Snelling.