Smithsonian Under Secretary for Science David L. Evans has resigned, effective April 21. Evans joined the Smithsonian in September 2002 to oversee its science museums and research facilities.

Cristián Samper, Acting Secretary of the Smithsonian, accepted Evans’ letter of resignation.

Samper named Ira Rubinoff, currently director of the Smithsonian Tropical Research Institute in Panama, as Acting Under Secretary for Science. The Smithsonian will begin a search for a permanent replacement in the coming weeks.

Rubinoff, 68, has directed the Smithsonian Tropical Research Institute since 1974. The Institute furthers the understanding of tropical nature and its importance to human welfare, trains students to conduct research in the tropics and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems.

In his letter of resignation, Evans said, “The opportunity to contribute to one of the world’s great institutions has been inspiring and motivating for me.” Evans noted that he has been speaking widely on a variety of science topics, and he has begun to outline a book.

“While it is with great affection for all of my colleagues and some reluctance, I feel that I must resign my position at the Smithsonian to adequately chart my own course. I will continue to support the Institution as one of its millions of admirers, one of the lucky few who have had the chance to be directly involved.”

As Under Secretary for Science, Evans oversaw several museums and research centers and institutes at the Smithsonian, including the National Museum of Natural History; National Zoological Park and its Conservation and Research Center in Virginia; National Air and Space Museum; Smithsonian Astrophysical Observatory in Massachusetts; Smithsonian Tropical Research Institute in Panama; Smithsonian Environmental Research Center near the Chesapeake Bay in Maryland; National Science Resources Center in Washington, D.C.; and Museum Conservation Institute in Maryland.