Rennie joined the staff of Scientific American as a member of the Board of Editors in 1989, having previously worked as a science writer covering biology, technology, and medicine for a variety of publications. He helped plan and edit several of Scientific American’s distinguished single-topic issues, including Mind and Brain (Sept. 1992, the best-selling issue in SA’s history) and Life, Death and the Immune System (Sept. 1993, later republished as a book by W.H. Freeman).

As Editor in Chief, Rennie oversaw such single-topic issues as Key Technologies for the 21st Century (Sept. 1995), What You Need to Know About Cancer (Sept. 1996) and A Matter of Time (Sept. 2002) All three of these issues were nominated for National Magazine Awards; What You Need to Know About Cancer and A Matter of Time both won for editorial excellence as Single-Topic Issues.

In September 2003 the Potomac Institute for Policy Studies honored Rennie with its Navigator Award for distinguished service in support of national science and technology policy. In 2000 the Council of Scientific Society Presidents bestowed on Rennie its Sagan Award for Public Understanding of Science, which is given annually “to honor those who have become concurrently accomplished as researchers and/or educators, and as widely recognized magnifiers of the public's understanding of science.”

Rennie received his B.S. degree from Yale University in 1981, after which he worked for several years in a laboratory at Harvard Medical School before embarking on his career as a science writer. His writing has appeared in The Economist, The New York Times, Longevity, and other publications. His numerous television and radio appearances include the ABC World News Weekend, PBS Newshour with Jim Lehrer, Entertainment Tonight, CBS Early Show, and National Public Radio’s Science Friday.
Scientific American, founded in 1845, is the foremost publication for individuals who want to understand the science and technology that is shaping our world. Editorial contributors have included over 130 Nobel laureates, among them Albert Einstein, Neils Bohr, Francis Crick, Stanley Prusiner and Harold Varmus. Scientific American, Inc. is a division of Holtzbrinck Publishers, a U.S. subsidiary of Verlagsgruppe Georg von Holtzbrinck GmbH, a privately held international media corporation operating in more than 40 countries.