Human beings are in a category of their own when it comes to making vocalizations, developing the ability to have spoken language that no other animal has come close to. But as it turns out, scientists have found that baboons can do something very human-like: create human-style vowel sounds.

Scientists have been trying to understand how speech has developed so they’ve been turning to our closest relatives, primates, for answers. They’ve noticed that the human’s voice box has a different position, while other primates have a high larynx, which scientists think may be necessary to produce distinct vowel sounds, the key to spoken language, according to a PLOS statement.

But after discovering that baboons can produce five vowel sounds in their calls, scientists behind the study think this may not be the unique characteristic of human vocalizations at all. And it may indicate the roots of our speech may be much deeper back in our species’ history.

The abstract of the paper reads: “Language is a distinguishing characteristic of our species, and the course of its evolution is one of the hardest problems in science. It has long been generally considered that human speech requires a low larynx, and that the high larynx of nonhuman primates should preclude their producing the vowel systems universally found in human language. Examining the vocalizations through acoustic analyses, tongue anatomy, and modeling of acoustic potential, we found that baboons (Papio papio) produce sounds sharing the F1/F2 formant structure of the human [ɨ æ ɑ ɔ u] vowels, and that similarly with humans those vocalic qualities are organized as a system on two acoustic-anatomic axes. This confirms that hominoids can produce contrasting vowel qualities despite a high larynx. It suggests that spoken languages evolved from ancient articulatory skills already present in our last common ancestor with Cercopithecoidea, about 25 MYA.”