Though explaining the entire human genetic blueprint is still a few years away, scientists have begun laying claim to the stretches of DNA whose codes they have succeeded in cracking. In recent years researchers have flooded the U: S. Patent and Trademark Office with applications for thousands of genes and gene fragments -- and they have stirred a lot of controversy in the process. The biggest problem with patenting genes is that while scientists have at least a general idea of what specific stretches of genetic coding do, often it’’s just that general. Investigators do sometimes succeed in isolating a single, crisp gene with a single known function. Often, however, researchers trying to map genes set no further than marking off fragmentary stretches of DNA that may be thousands of bases in length. These so-called expressed sequence tags may have real genetic information embedded in them, but determining where those fragments are and what their structure is takes more digging. Geneticists have lately been filing patent applications for these ESTs anyway. "I would guess that in many cases the scientists didn’’t even ex amine all the material," says Bruce Lehman, commissioner of the Patent and Trademark Office. Not only can such filings be careless genetics, they can also be bad business. EST applications may lead to so-called submarine patents, claims that are made today and then vanish, only to reappear when some unsuspecting scientist finds something useful to do with genes hidden in the patent. More troubling is an economic issue. If the entire genetic schematic is preemptively(抢先) owned by the research teams studying it now, where is the incentive for independent scientists -- often sources of great innovation -- to work on it later Licensing costs, warns Jeffrey Kahn, director of the University of Minnesota’’s Center for Bioethics, could hold medical progress hostage. Patenting supporters insist that an equally persuasive argument could be made that the large genome-mapping groups need patent protection to make their work worthwhile to them. Stickier than the economic question is the ethical one. Most of us shrink from the idea of anyone’’s owning the rights to any part of the human form. Besides, if the first anatomist(解剖学家)to spot, say, the pancreas(胰腺)was not granted title to it, why should modern genome mapping(其因组图的) scientist be able to claim even a single gene That kind of argument is grounded not in law but in the very idea of what it means to be human – an issue that even the highest federal court is not likely to settle. The word "submarine" (Line 2,. Para. 3) is closest in meaning to "______".