It is the best of times and worst of times to start a science career in the United States. Researchers today have access to powerful new tools and techniques--such as rapid gene sequencers and giant telescopes--that have accelerated the pace of discovery beyond the imagination of previous generations. But for many of today's graduate students, the future could not look much bleaker. They see long periods of training, a shortage of academic jobs, and intense competition for research grants looming ahead of them. Although the operating assumption among many academic leaders is that the nation needs more scientists, some of brightest students in the country are demoralized and bypassing scientific careers. The problem stems from the way the United States nurtures its developing brainpower--the way it trains, employs, and provides grants for young scientists. For decades, blue-ribbon panels have called for universities to revise graduate doctoral programs, which produced a record-high 27,974 Ph.D.'s in science and engineering in 2005. No less a body than the National Academy of Sciences has, in several reports, urged doctoral programs to train science students more broadly for jobs inside and outside academe, to shorten Ph.D. programs, and even to limit the number of degrees they grant in some fields. Despite such repeated calls for reform, resistance to change has been strong. Major problems persist, and some are worsening. (Contains 1 table and 1 figure.)