Dr. Phillip Gilley, of the department of speech, language and hearing science, speaks about the use of symbols in language during Darwin Day at the CU Museum of Natural History on Feb. 18, 2012. Gilley’s speech, entitled “The Evolution of Language,” addressed how language and speech have formed throughout history. The Darwin Day celebration was organized by the Secular Students and Skeptics Society. (CU Independent/Robert R. Denton)
