John E. Hopcroft, the IBM Professor of Engineering and Applied Mathematics in Computer Science, and Eric Siggia, adjunct professor of physics, have been elected to the National Academy of Sciences.

They are two of 72 new members who are being recognized for their distinguished and continuing achievements in original research; in all, there are 2,150 active members.

The National Academy of Sciences is a private organization of scientists and engineers dedicated to furthering science and its use for the general welfare. Established in 1863 by a congressional act of incorporation signed by Abraham Lincoln, the academy is intended to act as an official adviser to the federal government, upon request, in any matter of science or technology.

Hopcroft joined the Cornell faculty in 1967, was named professor in 1972 and the Joseph C. Ford Professor of Computer Science in 1985. He served as chairman of the Department of Computer Science from 1987 to 1992 and was associate dean for college affairs in 1993. From 1994 to 2001, he was the Joseph Silbert Dean of Engineering. His research centers on theoretical aspects of computing, especially analysis of algorithms, automata theory and graph algorithms.

He is also a member of the National Academy of Engineering and a fellow of the American Academy of Arts and Sciences, American Association for the Advancement of Science, Institute of Electrical and Electronics Engineers, and Association for Computing Machinery. In 1992 President George H.W. Bush appointed him to the National Science Board, which oversees the National Science Foundation; he served until 1998. From 1995 to 1998, Hopcroft served on the National Research Council's Commission on Physical Sciences, Mathematics and Applications.

He was honored with the A.M. Turing Award, considered by many to be the equivalent of a Nobel Prize in computer science, in 1986.

Siggia came to Cornell in 1977, after completing undergraduate and graduate studies at Harvard University. He became a full professor of physics in 1985. In 1997 he became professor of physics at Rockefeller University, but continued as an adjunct professor at Cornell. He spends summers and occasional weeks at Cornell, collaborating with faculty members and supervising several physics graduate students.

His research is in biophysics, analyzing the behavior of biological molecules in terms of the physical laws that govern their motion. Recently he has focused on genes that regulate the expression of genes and their influence in evolution and on the physical form of a growing organism.