The 2014 slate of spring semester Penn Science Café and Penn Lightbulb Café lectures includes conversations about friendly-looking rodents, killer robots, “green” vaccines, and Martin Luther King, Jr.

The Science Café kicks off on Feb. 11 with a talk by Etienne Benson, an assistant professor in the Department of History and Sociology of Science, who will discuss “How the Gray Squirrel Conquered the American City.” In the second half of the 19th century, squirrels were intentionally released in public squares, town greens, and urban parks across the country; Benson studies how squirrels flourished in their new environment.

On Feb. 25, the Penn Lightbulb Café opens with Tukufu Zuberi, the Lasry Family Professor of Race Relations in the Department of Sociology. Zuberi, who is also a professor of Africana studies, will speak about “The Other African-Americans,” examining the history of African descent populations in Latin America and why the political center of Africans and the African Diaspora is shifting to Brazil, Colombia, and other Latin American nations.

Thomas Sugrue, the David Boies Professor of History and Sociology in the Department of History, was originally scheduled to open the Lightbulb Café in January with his lecture, “The Martin Luther King Jr. We Have Forgotten.”

Sugrue’s talk, which challenges the myths surrounding King and his politics, and explores his relationship to conservatives, moderates, liberals, and radicals, has been rescheduled for March 25.

The spring café lineup also includes a presentation by Michael Horowitz, an associate professor in the Department of Political Science, who will discuss the future of war, and a special Science Café presented as part of the Philadelphia Science Festival.

Science and Lightbulb Café lectures are held on Tuesday evenings at World Cafe Live Upstairs, 3025 Walnut St. Each hour-long talk begins at 6 p.m. and is followed by an audience Q&A session. The events are free and open to the public, but seating is limited. To register, contact Gina Bryan at 215-898-8721 or email bryangm@upenn.edu.

Both lecture series are presented by the School of Arts & Sciences and the Office of University Communications.

The full spring semester schedule is available at the Penn Lightbulb and Science Café website.