Evolutionary Investigation Across Species Reveals Primate Voice Boxes Are Evolving at Rapid Pace

Gorilla Skull and Larynx

Gorilla skull and larynx. Credit: Copyright Dr Jacob Dunn, Anglia Ruskin University (ARU)

Study is largest ever investigation into evolution of larynges across species.

Scientists have discovered that the larynx, or voice box, of primates is significantly larger relative to body size, has greater variation, and is under faster rates of evolution than in other mammals.

Published in the journal PLOS Biology and led by academics from Anglia Ruskin University (ARU), Stanford University, and the University of Vienna, the research is the first large-scale study into the evolution of the larynx.

Gorilla Larynx 3D

3D image of a gorilla larynx. Credit: Copyright Dr Jacob Dunn, Anglia Ruskin University (ARU)

The larynx has three main functions: protecting the airway during feeding, regulating the supply of air to the lungs, and vocal communication. Because of its important role in facilitating social behavior, through vocalization, it has long been believed that the larynx is a key area of evolution, particularly in species with highly developed vocal communication systems.

The researchers made CT-scans of specimens from 55 different species, and produced 3D computer models of their larynges. These were studied alongside detailed measurements, including body length and body mass.

The primates ranged in size from a pygmy marmoset (Cebuella pygmaea) weighing just 110g, to a Western gorilla (Gorilla gorilla) weighing approximately 120kg. The carnivorans spanned from a 280g common dwarf mongoose (Helogale parvula) to a 180kg tiger (Panthera tigris).

The study found that, for a given body length, primate larynges are on average 38% larger than those of carnivorans, and that the rate of larynx evolution is faster in these species.

There is also more variation in larynx size relative to body size among primates, indicating that primates have greater flexibility to evolve in different ways. Carnivorans follow more of a fixed larynx-size to body-size ratio.

Larynx size was also found to be a good predictor of the call frequency of a species, which demonstrates the relevance for vocal communication of the observed size variations.

Co-lead author Dr. Jacob Dunn, Reader in Evolutionary Biology at Anglia Ruskin University (ARU), said: “This study demonstrates clear differences in the evolution of the larynx between groups of mammals.

“Specifically, we have shown for the first time that the primate larynx is larger, less closely linked to body size, and under faster rates of evolution than the carnivoran larynx, which is a well-matched comparison group, indicating fundamental differences in the evolution of the vocal organ across species.”

Co-lead author Dr. Daniel Bowling, Instructor in Psychiatry and Behavioral Sciences at Stanford University, added: “Our study also shows that differences in larynx size predict changes in voice pitch, highlighting the larynx’s crucial role in vocal communication. This is demonstrated by the rich and varied calls produced by many primate species.

“The results imply fundamental differences between primates and carnivorans in the forces constraining larynx size, as well as highlighting an evolutionary flexibility in primates that may help explain why they have developed complex and diverse uses of the vocal organ for communication. This provides an exciting avenue for future studies examining variation among other mammalian groups.”

Reference: “Rapid evolution of the primate larynx?” by Daniel L. Bowling, Jacob C. Dunn, Jeroen B. Smaers, Maxime Garcia, Asha Sato, Georg Hantke, Stephan Handschuh, Sabine Dengg, Max Kerney, Andrew C. Kitchener, Michaela Gumpenberger, W. Tecumseh Fitch, 11 August 2020, PLOS Biology.
DOI: 10.1371/journal.pbio.3000764

14 Comments on "Evolutionary Investigation Across Species Reveals Primate Voice Boxes Are Evolving at Rapid Pace"

  1. This is yet another finding that shows we have no ‘human uniqueness’ that sets us apart from other species.

    We used to think we had defining traits that only humans have… Tool use was one – not so!

    In fact, any possible superiority we thought we had has been pretty well debunked by scientists.

  2. Planet of the Apes!

  3. Thomas Candlish | August 11, 2020 at 5:22 pm | Reply

    This whole study is flawed. The premiss is that primate species are connected through a linkage based on evolutionary similarities. There is no biological evidence that proves there are any similarities. Our ability to see physical similarities is a fault of the limited human brain and its juvenile attempt to group like objects together. Unless you are able to show a beneficial hereditary physical mutation within a specific animal type, your premiss of cross species similarities and differences are purely conjecture. So much research is based on this, yet none have been able to produce a single example.

    • You’re ignoring a lot of scientific evidence. I’ve only seen such dismissive behaviour towards evolution from a creationist.

      • Torbjörn Larsson | August 12, 2020 at 4:28 pm | Reply

        But if he is thusly superstitious – and the false premiss seem familiar – what is he doing on a science site?

        It isn’t as if non-superstitious people intrude on their magic rituals and start to describe reality. So why would he be purposefully rude? That is also astounding!

      • Creationists are those who just have given their ignorance a name. Suppose there is a creator – giving him a name doesn’t solve anything. It’s like saying that the answer to an arithmetic problem is ‘x’. The questions creationists must answer are: how does the creator create? Why do species go extinct if creator is perfect? Why do we see vestigial organs that do nothing? Why do we see genes that do nothing (but did something earlier in another species)? And most importantly, who created this very awesome creator? And who created the Creator’s creator and so on

    • Torbjörn Larsson | August 12, 2020 at 4:25 pm | Reply

      Just *all the available evidence* test successfully (not “prove” as in math), with no evidence testing against. This is easily checked with the nearest encyclopedia referencing the evidence (see e.g. “evolution”).

      Why anyone would try to troll the science based on no evidence whatsoever is astounding. Also, based on outright false and “flawed premiss” since evolution happens whether or not mutations are selected for (“beneficial”) as in adaptive mutations. Evolution, which is the basic process of biology which diversify and speciaty, works with differential reproduction among populations of organisms. A useful model is the bath tub model of genome allele variation, where mechanisms such as mutation, recombination and gene flow (migration) increase variation, and mechanisms such as selection, drift and inbreeding decrease variation. Drift, which is the most common allele fate, is caused by near neutral selection and happens for 95 % of gene sites in model animal mammals (mice), while fixating selection is negative and happens for 3-4 % of sites and adaptive selection is positive and happens for the smallest part. The likelihood that a beneficial mutation would immediately cause a trait is almost zero and the idea has been rejected under the label “hopeful monsters” – remember that this was a pre-darwinian idea that died with evolution (see e.g. “saltation (biology)” in an encyclopedia).

      For easy examples of beneficial trait evolution we have many lab examples, such as evolving multicellularity in yeast models (takes about a year, a nice student project). For examples of observed speciation, there is a list of 200+ examples., And for testing evolution, anyone can do that in a few minutes by going to, say, NCBI site, BLAST a protein gene for evolutionary homology and tree the result – this protein speciation can only happen under the process of evolution.

      This is Biology 101.

      • Torbjörn Larsson | August 12, 2020 at 4:45 pm | Reply

        I should add that NCBI has lots of material for how to do the blasting and treeing, and its all free software. So there is very little reason – if you want to test evolution yourself and confirm what all the scientists agree on – not to try it.

  4. … The language is a very important skill to have, but there is a way more difference in a language humans use and primates use. There are some forms of communication in other species, however that is bit questionable. Because, one needs to set the language in order to compare to other languages…
    … Who, knows there might be some language humans are incapable to comprehend to even be a communication after all.
    Humans might be the best developed species, but that doesn’t mean that humans are the best at everything of everything….

    There was an experiment one Bonobo was able to develop some language skills, but not enough words. Now I wonder, how it would be if the creature started to learn on very early age of its life, and what would happened if that ape was introduced into species of other wild animals too.

    So many ideas…

    • Torbjörn Larsson | August 12, 2020 at 4:32 pm | Reply

      All extant species are equally evolved (“developed”), 4 billion years of evolution history. So it is easy to agree that “best” is a relative measure here.

  5. Babu G. Ranganathan | August 12, 2020 at 2:24 pm | Reply

    (B.A. Bible/Biology)*

    ONLY LIMITED EVOLUTION (micro-evolution or evolution within biological “kinds”) is genetically possible (such as the varieties of dogs, cats, horses, cows, etc.), but not macro-evolution, or evolution across biological “kinds,” (such as from sea sponge to human). All real evolution in nature is simply the expression, over time, of already existing genes or variations of already existing genes. For example, we have breeds of dogs today that we didn’t have a few hundred years ago. The genes for these breeds had always existed in the dog population but never had opportunity before to be expressed. Only limited evolution, variations of already existing genes and traits, is possible.

    The genes (chemical instructions or code) for a trait must first exist or otherwise the trait cannot come into existence. Genes instruct the body to build our tissues and organs. Nature is mindless and has no ability to design and program entirely new genes for entirely new traits.

    Evolutionists believe that, if given millions of years, accidents in the genetic code of species caused by the environment will generate entirely new code making evolution possible from one type of life to another. It’s much like believing that by randomly changing the sequence of letters in a romance novel, over millions of years, can turn the novel into a book on astronomy! Not to worry. We’ll address the issue of “Junk DNA” in a moment.

    WHAT ABOUT NATURAL SELECTION? Natural selection doesn’t produce biological traits or variations. It can only “select” from biological variations that are possible and which have survival value.

    HOW COULD SPECIES HAVE SURVIVED if their vital tissues, organs, reproductive systems, etc. were still evolving? A partially evolved trait or organ that is not complete and fully integrated and functioning from the start would be a liability to a species, not a survival asset. Plants and animals in the process of macro-evolution would be unfit for survival. For example, “if a leg of a reptile were to evolve (over supposedly millions of years) into a wing of a bird, it would become a bad leg long before it became a good wing” (Dr. Walt Brown, scientist and creationist). Survival of the fittest actually would have prevented evolution across biological kinds!

    NEW SPECIES BUT NOT NEW DNA: Although it’s been observed that new species have come into existence, they don’t carry any new genes. They’ve become new species only because they can’t be crossed back with the original parent stock for various biological reasons. A biological “kind” allows for new species but not new genes. Nature has no ability to invent new genes for new traits. Only limited variations and adaptations are possible in nature, and all strictly within a biological “kind” (i.e. varieties of dogs, cats, etc.).

    Dr. Randy J. Guliuzza’s extensive research points to a better explanation than natural selection for variation and adaptation in nature. Dr. Guliuzza explains that species have pre-engineered mechanisms that enable organisms to continuously track and respond to environmental changes with system elements that correspond to human-designed tracking systems. This model is called CET (continuous environmental tracking). His research strongly indicates that living things have been pre-engineered to produce the right adaptations and changes required to live in changing environments. It’s much like a car that’s been pre-engineered so that the head lights turn on automatically when day changes to night.

    What about genetic and biological similarities between species? Genetic information, like other forms of information, cannot happen by chance, so it is more logical to believe that genetic and biological similarities between all forms of life are due to a common Designer who designed similar functions for similar purposes. It doesn’t mean all forms of life are biologically related! Only genetic similarities within a natural species proves relationship because it’s only within a natural species that members can interbreed and reproduce.

    Many people have wrong ideas of how evolution is supposed to work. Physical traits and characteristics are determined and passed on by genes – not by what happens to our body parts. For example, if a woman were to lose her finger this wouldn’t affect how many fingers her baby will have. Changing the color and texture of your hair will not affect the color and texture of your children’s hair. So, even if an ape or ape-like creature’s muscles and bones changed so that it could walk upright it still would not be able to pass on this trait to its offspring. Only changes or mutations that occur in the genetic code of reproductive cells (i.e. sperm and egg) can be passed on to offspring.

    What about the new science of epigenetics? Epigenetics involves inheritable factors which can turn already-existing genes on, but epigenetics doesn’t create new genes.

    Most biological variations are from new combinations of already existing genes, not mutations. Mutations are accidents in the genetic code caused by nature (i.e. environmental radiation), are mostly harmful, and have no capability of producing greater complexity in the code. Even if a good accident occurred, for every good one there would be hundreds of harmful ones with the net result, over time, being harmful, even lethal, to the species. Even if a single mutation is not immediately harmful, the accumulation of mutations over time will be harmful to the species resulting in extinction. At very best, mutations only produce further variations within a natural species.

    All species of plants and animals in the fossil record are found complete, fully formed, and fully functional. This is powerful evidence that all species came into existence as complete and fully formed from the beginning. This is only possible by creation.

    God began with a perfect and harmonious creation. Even all the animals were vegetarian (Genesis 1:30) in the beginning and did not struggle for survival nor kill and devour each other. Macro-evolutionary theory does not begin with a perfect and harmonious creation as the Bible states. The Bible and macro-evolutionary theory cannot both be true.

    All the fossils that have been used to support human evolution have been found to be either hoaxes, non-human, or human, but not non-human and human (i.e. Neanderthal Man was discovered later to be fully human).

    There has never been unanimous agreement among evolutionary scientists on ANY fossil evidence that has been used to support human evolution over the many years, Including LUCY.

    The actual similarity between ape and human DNA is between 70-87% not 99.8% as commonly believed. The original research stating 99.8% similarity was based on ignoring contradicting evidence. Only a certain segment of DNA between apes and humans was compared, not the entire DNA genome.

    Also, so-called “Junk DNA” isn’t junk. Although these “non-coding” segments of DNA don’t code for proteins, they have recently been found to be vital in regulating gene expression (i.e. when, where, and how genes are expressed, so they’re not “junk”). Also, there is evidence that, in certain situations, they can code for protein.

    ARE FOSSILS REALLY MILLIONS OF YEARS OLD? (Internet article by author)

    Visit my latest Internet site: THE SCIENCE SUPPORTING CREATION (This site answers many arguments, both old and new, that have been used by evolutionists to support their theory)


    *I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I’ve been privileged to be recognized in the 24th edition of Marquis “Who’s Who in The East” for my writings on religion and science.

    • Torbjörn Larsson | August 12, 2020 at 4:32 pm | Reply

      That’s erroneous superstition. Read the article instead.

    • Torbjörn Larsson | August 12, 2020 at 4:40 pm | Reply

      Oh, I’m, sorry, I didn’t read through the superstition “false premiss” lede – I now see there are erroneous claims on science as well. For a description of evolution that in simple terms (bath tub model and observed allele fates in mice models) see my comment to Thomas Candlish which should respond to all of that. (After filtering out your superstitious based nonsense, too much to list it all since you gish gallop.) With tips on references through the encyclopedia keywords.

      Also, I know not the self promotion – again a sure sigh of no science (a science reader want peer review published references).

      • Torbjörn Larsson | August 12, 2020 at 4:41 pm | Reply

        “Oh, I’m, sorry” – Oh, I’m sorry,
        “I know not” – I now note.

        I now note that I need more coffee. 😀

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