TUSCALOOSA, Ala. – The nation's top-selling weed killer, atrazine, disrupts the sexual development of frogs at concentrations 30 times lower than levels allowed by the Environmental Protection Agency, according to research published by a University of California, Berkeley scientist who will speak at The University of Alabama on March 25.

Dr. Tyrone Hayes’ talk entitled “Common Groundsel, Hermaphroditic Frogs, and Premature Babies: Today’s Solutions, Tomorrow's Problem” is the 7th annual William Darden Lecture and will be at 7 p.m. in room 127 of UA’s Biology Building.

Hayes, associate professor of developmental endocrinology, and his colleagues have reported that atrazine at levels often found in the environment demasculinizes tadpoles and turns them into hermaphrodites -- creatures with both male and female sexual characteristics.

The lecture, which is free and open to the public, is co-sponsored by UA’s department of biological sciences and the Howard Hughes Medical Institute Undergraduate Science Program Award.

The annual William Darden Lecture is named after the professor emeritus of biological sciences and long-time chair of the department in UA’s College of Arts and Sciences who completed 31 years of service to the University. Mrs. Ilouise Hill and friends established the lecture fund.