Another Theory About the Origin of Speech
It also suggests we Homo sapiens weren't the first to form spoken language
Hiya!
Not a day goes by that we don’t use language in some form, yet rarely do we wonder how or when language began. Who was the first to speak aloud? What did they say? And why did they say anything at all? Was spoken language an evolution for our ancient Homo sapiens relatives that separated us from other hominin species? Or did we learn it? Luckily for us, researchers are also curious about these questions and more.
While we may never fully know the answers, experts have a couple of convincing theories. One idea, which I wrote about before, suggests caregivers (presumably maternal figures) created spoken language to make community childcare easier. Now, a new theory proposes verbal language emerged due to changes in the climate — and there’s some surprising evidence to support the claim.
When Did Verbal Language Originate?
Exactly when language developed is still hotly debated, with experts arguing Homo sapiens evolved spoken language anywhere between 50,000 to 100,000 years ago. Though a growing pile of research suggests that we Sapiens weren’t the first to develop spoken language — other hominin species, including the Neanderthals, likely used some form of verbal language long before we even came around.
But the new research I’ll tell you about soon presents evidence that language likely evolved significantly earlier — closer to millions of years ago as opposed to tens or hundreds of thousands. More specifically, the researchers propose verbal language evolved between 5.3 and 16 million years ago, during the Miocene era.
Miocene Epoch
The Miocene is part of the larger Neogene period, encompassing two epochs. The Miocene epoch was the first and longest of the two — lasting between 23.03 and 5.33 million years ago (mya) — and was divided into six timeframe categories, each spanning roughly 18 million years.
The Miocene was followed by the Pliocene epoch, which lasted from 5.33 to 2.58 mya, before being replaced by the Pleistocene, also known as the Ice Age, which ended merely 11,700 years ago.
The Miocene epoch was a period of chaos while Earth transformed. Continents shifted. Ocean currents morphed. Kelp forests grew then shifted the entire oceanic ecology. Meanwhile, on land, especially between 5.3 and 16 mya, the planet shed its dense forests in favor of wide open plains in the Northern Hemisphere.
The new grassland habitats were far different than the forests and so supported new mammalian species — including several new horses and at least some hominids, which had been living in the treetops. During this time, experts believe hominids adapted from mainly living in trees to spending more time on the ground — and this transition is what researchers at the University of Warwick in Coventry, England, believe spurred the evolution of spoken language.
New Research
In December 2023, the journal Nature published research by Charlotte Gannon, a Ph.D. candidate at the University of Warwick’s Department of Psychology and one of the lead authors of the paper, and her colleagues. The study includes experiments involving orangutans to show how verbal language could have evolved when hominids transitioned to living on the ground.
The researchers ventured to the savanna in South Africa — similar to the landscape hominids would have lived during the Miocene — where they studied two types of orangutan calls. They chose orangutans because they are the last remaining great apes that still predominantly live in trees — called arboreal great apes. Orangutans are also the largest tree-living animal on the planet.
Gannon told abc News that scientists use orangutan calls as a “bit of a time machine” to help them understand what speech might have been like during certain periods. In this case, orangutan calls are likely the closest examples modern scientists have to what ancient hominid calls may have sounded like when they moved from tree to ground living.
The first type of orangutan call the researchers studied, which they named a “kiss squeak,” is a “proto-consonant” because the sound is made when an orangutan uses their lips, tongue, or jaw, or closes their mouth to create the noise. Meanwhile, they refer to the second call as a “grumph” known as a “proto-vowel” because it can be made without mouth movements.
The Results
The team played the sounds in an open landscape and discovered something surprising. The kiss squeaks traveled significantly farther than the grumphs did across the plains. Their finding is particularly noteworthy because most modern languages have a strong consonant-to-vowel-ratio. Gannon told abc News:
"It tells us a little bit more about how we may have actually relied on consonants a bit more in order to pass our messages across, pass information across, especially once we've moved to these further landscapes. We were trying to communicate with each other in greater distances."
The researchers think a consonant-heavy vocabulary developed to help hominids communicate across open spaces where distances between individuals were far greater than when they lived in trees.
It makes sense that hominids would use sounds — whether calls or some primitive words — to communicate across fields, so why were the researchers surprised by their findings? Because the results conflict with what we know about the science of sound.
Wait a minute…
Gannon and her colleagues were stunned by the results of their experiments because, according to the science of sound propagation, the low-frequency grumph vowels should travel farther than the kiss squeak constant sound, which is made at a higher frequency.
Yet, the study showed the opposite happening. The higher-frequency kiss squeaks traveled farther than the low-frequency grumphs — and the differences were significant.
The study reports that after about 410 feet (125 meters), the vowel-based grumphs grew substantially quieter, while the kiss squeak consonant calls remained audible until about 830 feet (250 meters) before dropping off. At about 1,300 feet (400 meters), fewer than 20 percent of the vowel-based grumps were audible compared to about 80 percent of the kiss squeak consonant calls.
Granted, if verbal language did originate during the Miocene era, it still had millions of years to evolve before our Homo sapien ancestors evolved to learn it. But, Gannon noted that it nevertheless would have been a “pivotal” turning point for expanding and developing speech. She told abc:
"I think the ecological landscape that we experienced at the time had a really profound impact on this emerging language that we ended up with."
Yet, even if we Sapiens didn’t invent spoken language, Gannon says we appear to be the only hominid species to emerge with such rich and complex languages — that we know of, at least.
Perspective Shift
The idea that language developed to help hominids communicate across farther distances reminds me a bit of elephants, and how their rumble frequencies travel vast distances. Researchers believe this allows elephant tribes to remain in contact as they travel. I suppose it’s also similar to whale or dolphin calls in the ocean — which can travel thousands of miles.
Then again, when Nature finds something that works, it repeats it as often as possible. So perhaps it’s less surprising.
When I first learned about Gannon’s research, I wondered if it would replace the theory I mentioned at the beginning — that caregivers developed language to coordinate childcare and labor easier — but I don’t see why both theories can’t be true.
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Always interesting, Katrina.