A recent study revealed on Wednesday that an Indianapolis Zoo ape mimicked human speech for the very first time. The orangutan’s mimics give researchers a better understanding of human’s spoken language evolution.

As part of an experiment, Rocky the orangutan imitated sounds at the Indianapolis Zoo in the International Orangutan Center. Rocky was able to produce both “vowel-like” and “consonant-like” sounds. Researchers got to the conclusion that the vocal capacity constitutes a crucial prerequisite for the onset of spoken language evolution. The study, published Wednesday in the journal Scientific Reports, reveals that orangutans can mimic human vocalizations.

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Meet Rocky, “his remarkable vocalizations give clues to the evolution of human speech!” said the Indianapolis Zoo. Image credit: Indianapolis Zoo Facebook.

During the three-year experiment, researchers played a “do-as-I-do” game with an eleven-year-old orangutan. Rocky was encouraged to try to produce sounds in his vocal range. Researchers reported they attempted to teach him new vocal sounds without interfering his environment or daily routine.

Rocky was challenged to match human-produced sounds greatly varying in tone and pitch. It was observed that Rocky had abilities to produce “wookies” (orangutan’s normal vocal range noises), which were randomly modulated in pitch and tone.

Researchers determined that Rocky’s calls were unusual when they compared Rocky’s sounds with over 12,000 hours of footage containing wild and captive orangutan noises. The results give scientist a better understanding of human’s spoken language evolution.

Apes had no vocal control

Researchers might reconsider previous postulations saying that apes have vocal control over the sounds they produce. Before the study, the scientific community believed that apes had no abilities to learn new vocalizations. In fact, Indianapolis Zoo Director Dr. Rob Shumaker and co-author of the study, argues he had never heard any other apes like orangutans make those noises.

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Apes might control their vocal sounds. Image credit: Indianapolis Zoo

Such absence in apes to control vocal sounds led to the assumption that humans developed conversational speech abilities after divergence from great apes. The new findings point out that human speech ability might have started evolving 10 million years ago.

“Instead of learning new sounds, it has been presumed that sounds made by great apes are driven by arousal over which they have no control. But our research proves that orangutans have the potential capacity to control the action of their voices,” wrote lead researcher, Adriano Lameria.

Source: Nature