DURHAM, ENGLAND—A study led by Adriano Lameira, now of Durham University, suggests that ancestral great apes may have had control of their voices. It had been thought that great apes could only make sounds driven by arousal, but an adolescent orangutan named Rocky, who is housed at the Indianapolis Zoo, has produced more than 500 vowel-like calls in imitation of researchers. While working at the University of Amsterdam, Lameira and his team compared Rocky’s new calls with a database of recorded orangutan calls to make sure that they were learned sounds. “This opens up the potential for us to learn more about the vocal capacities of early hominids that lived before the split between the orangutan and the human lineages to see how the vocal system evolved towards full-blown speech in humans,” Lameira said in a UPI report. To read in-depth about a possible human ancestor, go to "Ardipithecus: Ape or Ancestor?"