Is Speech Far Older than Once Thought?
How one minor finding birthed a revolution by Darwinists
by Jerry Bergman, PhD
Speech is considered the cornerstone of the human species that separates us from all lower primates. Speech requires numerous essential articulators, including the teeth, tongue, jaw, lips, a descended larynx and several critical brain structures including Broca’s and Wernicke’s areas.[1] No earthly creature has speech except humans, in spite of controversial efforts to train various primates to learn sign language as an effective means of communication. By speech we mean the
complex multistage process that converts conceptual ideas into acoustic signals that can be understood by others. The stages include conceptualization of the intended message, word retrieval, selection of the appropriate morphological forms, sequencing of phonemes, syllables, and words, phonetic encoding of the articulatory plans, initiation, and coordination of sequences of movements in the tongue, lips, and laryngeal muscles that vibrate the vocal tract, and the control of respiration for vowel phonation and prosody.[2]
Given all of these requirements, in the 1930s to the 1950s, two pairs of researchers tested the possibility of teaching a home-raised chimpanzee to speak. They did this at both the same time and under, as far as possible, the same conditions as the researcher’s infant children.[3] The theory was that humans learn to verbalize by imitating the speech of those around them. If chimps were reared in the same environment, the theory was they too would learn to speak, or at least learn to use simple phrases effectively. A deaf child does not learn to speak properly because he never hears the acoustic patterns which make up words. Such is the chasm between humans and all other primates that it should have come as no surprise when all of their experiments to teach chimps to talk ended in failure.[4]
Credit: CNRS
In an attempt to understand why this failure occurred, a 1969 American researcher named Philip Lieberman focused on one critical trait required for speech, the location of the voice box, that portion of the respiratory (breathing) tract containing the vocal cords that produce audible sounds. In humans, the larynx is located between the pharynx and the trachea. In baboons and other apes it is located much higher, partly because of their very different lower jaw design as compared to humans.
The “Descended Larynx” Theory
From this observation Lieberman proposed the theory of the descended larynx (TDL) which postulates that when apes evolved into humans, the pharynx became longer, and the larynx was moved down towards the stomach. This new design allowed for vowel production variations, which is required to speak all the world’s known languages.
To understand the problem of ape-to-human speech evolution, we must understand how human speech is made. This requires knowledge of the parts of human speech and their importance for effective communication. Vowel sounds, voiced by the five letters A, E, I, O, U and sometimes Y, produce 25 different basic sounds. Consonants consisting of all the 21 non-vowels produce only 24 different basic sounds. Vowels produce sounds in which the articulators (lips, tongue, teeth plus the hard and soft palate) produce the correct shape but do not touch each other. A consonant is a speech sound that is not a vowel and is produced when articulators do touch other articulators or when at least one becomes very close to touching another. An example is when sounding the letter ‘B,” the lips must touch each other, producing a slight explosion when air is forced through to produce the sound.
Many speech languages also have three semi-consonants (r, w and y). Consonants make the hard sounds; the vowels make the sounds in-between the consonants. One or more vowels paired with one or more consonants makes a syllable, and syllables form words. The mouth and other structures involved in speech all must be able to form the 50 or so sounds to produce effective speech as required for all of the known world’s languages. In addition, for a language to effectively communicate more than just individual words, rules for making sentences as well as grammar must exist. These facts must be kept in mind when evaluating the research considered below.
Fate of the Descended Larynx Theory
Despite some serious criticisms and many acoustic observations that contradicted the descended larynx theory, it came to be generally accepted by most primatologists. The theory also predicted that before speech is able to emerge, among the many required developments, the larynx must descend toward the stomach to be able to produce differentiated vowels [see illustration above.]. The descended larynx theory’s “claim that only fully modern humans can produce contrasting vowels has been argued as restricting all aspects of language emergence to the past 200,000 years.”[5]
This view, although accepted for half a century, was challenged in 2019 when researchers learned that monkeys can produce well differentiated proto-vowels, or more accurately vowel-like utterances that sound very roughly like vowels, but are more like grunts, squeaks or other guttural sounds.[6] The researchers concluded that the
production of differentiated vocalizations is not therefore a question of anatomical variants but of control of articulators. This work leads us to think that speech could have emerged before the 200,000 years ago that linguists currently assert.[7]
From this observation came the unsupported speculation that the creation view which was once widely held can be discarded and the slow evolution view can now be seriously entertained:
Specifically, the idea of recent, sudden, and simultaneous emerging of speech and language is no longer plausible. The dawn of speech in the form of contrasting vowel sounds is not recent, but early. The full process of speech emergence was therefore not sudden but extended, probably occurring in stages about which we can now begin to theorize. scientists can now envisage much earlier speech emergence, as far back as at least 20 million years, a time when our common ancestor with monkeys lived, who already presumably had the capacity to produce contrasted vocalizations.[8]
This is a good example of how one finding leads to speculation that, in turn, leads to some unfounded generalization such as illustrated in the following headline, “Examining how primates make vowel sounds pushes timeline for speech evolution back by 27 million years.”[9] The study’s actual conclusions, based on their research, were far more modest:
we conclude from this preponderance of appropriately VTL- [vocal tract length] normalized evidence that multiple primate species, from gorillas, through certain Old World monkeys, to even lemurs, produce non-schwa vowel qualities through their VT’s [vocal tract] deviations from a uniform tube configuration. We further conclude that these counterexamples refute the core claims of LDT [laryngeal descent theory]: that pre-AMHS [anatomically modern Homo sapiens] hominids can only produce schwa-like vowels.[10]
The schwa sound (ǝ) is the most common vowel sound in many languages including English which sounds like an “ah,” the sound doctors ask patents to make when they examine their throat. The study concluded that their finding only indicated the repertoire of speech that baboons and other primates use is slightly greater than once thought. It does not change the essential fact that
Full language is unique to and universal in humans, where it is universally transmitted by vocal speech. Animals do communicate in various ways, including with vocal calls, but the structural complexity, flexibility, and integration of speech and language in humans are vastly greater than anything found in other species.[11]
Although “even among primates, laryngeal descent is not uniquely human,” no primate has evolved the ability to speak, not even close, even though Darwinists believe that they have had the same amount of time, and lived in very similar environments, to evolve speech as humans have, yet have not done so, nor have they even taken the first step towards evolving speech. The main takeaway for the Darwinists is
we believe that the present refutation of the LDT [laryngeal descent theory] should have a profound and liberating effect on our understanding of human evolution because, without the time limit imposed by LD [laryngeal descent], a variety of other hypotheses about language emergence can now be entertained.[12]
The next step is to determine if the sounds made by the primates have meaning that can be understood by other primates. Even this achievement is problematic because communication involves not only sounds, but the tone and aggression connected with the sounds as well as the facial and posture that accompanies the sounds. In short, the response to the study considered here has gone far beyond the evidence presented, which only has recorded and analyzed the a few simple sounds made by the primates the studies researched.
The fact is, it is still very true that “the gulf between the human and animal [communication] systems and specifically how the modern human system, language, emerged evolutionarily through extinct hominins from the lesser systems of our hominid ancestors has been called the hardest problem in science.”[13] The finding that primates can make a few vowel-like sounds does not change this fact.
References
New book by Dr Bergman addresses back pain and many other alleged cases of poor design in the human body.
[1] Price, Cathy; Jenny T. Crinion and Mairéad MacSweeney. 2011. A generative model of speech production in Broca’s and Wernicke’s areas. Frontiers in Psychology, September 16. | https://doi.org/10.3389/fpsyg.2011.00237.
[2] Price, 2011, p. 1.
[3] Kellogg, Winthrop. 1968. Communication and Language in the Home-Raised Chimpanzee. Science, 162(3852): 423-427, October 25.
[4] “Speech could be older than we thought.” http://www.cnrs.fr/en/speech-could-be-older-we-thought.
[5] Boë, Louis-Jean and Thomas R. Sawallis, et al., 2019. Which way to the dawn of speech?: Reanalyzing half a century of debates and data in light of speech science. Science Advances, 5(12): 1-23, p. 1.
[6] Boë, et al., 2019. p. 1.
[7] “Speech could be older than we thought.” http://www.cnrs.fr/en/speech-could-be-older-we-thought.
[8] “Speech could be older than we thought.” http://www.cnrs.fr/en/speech-could-be-older-we-thought.
[9] Sawallis, Thomas R. and Louis-Jean Boë, 2019. Examining how primates make vowel sounds pushes timeline for speech evolution back by 27 million years. https://phys.org/news/2019-12-primates-vowel-timeline-speech-evolution.html.
[10] Boë, et al., 2019, p. 19.
[11] Boë, et al., 2019, p. 1.
[12] Boë, et al., 2019, p. 20.
[13] Boë, et al., 2019, p. 1.
Dr. Jerry Bergman has taught biology, genetics, chemistry, biochemistry, anthropology, geology, and microbiology for over 40 years at several colleges and universities including Bowling Green State University, Medical College of Ohio where he was a research associate in experimental pathology, and The University of Toledo. He is a graduate of the Medical College of Ohio, Wayne State University in Detroit, the University of Toledo, and Bowling Green State University. He has over 1,300 publications in 12 languages and 40 books and monographs. His books and textbooks that include chapters that he authored are in over 1,500 college libraries in 27 countries. So far over 80,000 copies of the 40 books and monographs that he has authored or co-authored are in print. For more articles by Dr Bergman, see his Author Profile.