“If a field is missing, that student would not even get into the process,” he said.

That the omission occurred at all is worrying scientists concerned about threats to the teaching of evolution.

One of them, Lawrence M. Krauss, a physicist at Case Western Reserve University, said he learned about it from someone at the Department of Education, who got in touch with him after his essay on the necessity of teaching evolution appeared in The New York Times on Aug. 15. Dr. Krauss would not name his source, who he said was concerned about being publicly identified as having drawn attention to the matter.

An article about the issue was posted Tuesday on the Web site of The Chronicle of Higher Education.

Dr. Krauss said the omission would be “of great concern” if evolutionary biology had been singled out for removal, or if the change had been made without consulting with experts on biology. The grants are awarded under the National Smart Grant program, established this year by Congress. (Smart stands for Science and Mathematics Access to Retain Talent.)

The program provides $4,000 grants to third- or fourth-year, low-income students majoring in physical, life or computer sciences; mathematics; technology; engineering; or foreign languages deemed “critical” to national security.

The list of eligible majors (which is online at ifap.ed.gov/dpcletters/attachments/GEN0606A.pdf) is drawn from the Education Department’s “Classification of Instructional Programs,” or CIP (pronounced “sip”), a voluminous and detailed classification of courses of study, arranged in a numbered system of sections and subsections.