David Kimbrough Oller
Sunday, 8th October 2023
Details to follow
I am persuaded that water must have been involved in the natural selection of the vast differences between humans and our ape relatives. Many of these differences are anatomical, but among the most interesting is that humans uniquely possess massive control of vocalization, and perhaps even more important that humans engage in vocal activity at extremely high rates, 16,000 words a day (Mehl et al., 2007) . Ulrike Griebel and I have been arguing for more almost two decades that this vocal capacity and its enormous flexibility must have emerged in our ancient past in response to strong natural selection pressure. A preadaptive feature that made selection for vocal flexibilty possible was, according to our reasoning, hominin diving, which requires “conscious” control of the glottis, and we think, makes selection on other ways to use the glottis (e.g., in vocalizing freely) more likely.
In an evo-devo approach, we suggest the selection presssure leading to vocal flexibility would have been most likely to modify developmental patterns, and thus changes in vocalization would likely appear in babies first. A widespread belief is that infants learn to produce the sounds of their prelinguistic repertoires by imitating their parents. In fact, the vast majority of speech-like sounds (we call them “protophones”) produced by the human infant in the first year are endogenously generated, occurring at 4 to 5 per minute, every waking hour from the first month and throughout the first year (Oller et al., 2021) . Even infants born prematurely produce thousands of protophones daily while they are still in neonatal intensive care, two months before their due dates (Oller, Caskey, et al., 2019) . And profoundly deaf infants produce protophones at similar rates to hearing infants (Iyer & Oller, 2008).
Infants explore the protophones and play with them in much the same way they play with objects, which they tend ot pick up, turn in their hands, shake, and bite. As far as we know all apes use their hands to explore the world. But only the human infant appears ever to explore vocalization (Oller, Griebel, et al., 2019) . Other primates vocalize with innate screams, laughs, contact calls, and so on, to serve immediate social purposes. In contrast, even in laborartory recordings, 70% of the protophones of the human infant are directed to nobody, elicited by nobody (Long et al., 2020) . In all-day home recordings, it appears that even a larger percentage of protophones are directed to nobody. This massive difference between our species and all the other apes can be seen as soon as infants can breathe on their own. It appears that nothing about vocal language could be developed or evolved without first establishing a tendency to vocalize copiously and with functional flexibility, tendencies seen in the human infant from the first months of life and never at any age in other apes.
Iyer, S. N., & Oller, D. K. (2008). Prelinguistic vocal development in infants with typical hearing and infants with severe-to-profound hearing loss. Volta Review, 108,
Long, H. L., Bowman, D. D., Yoo, H., Burkhardt-Reed, M. M., Bene, E. R., & Oller, D. K. (2020). Social and endogenous infant vocalizations. PLoS One, 15(8), e0224956.
Mehl, M. R., Vazire, S., Ramírez-Esparza, N., Slatcher, R. B., & Pennebaker, J. W. (2007). Are Women Really More Talkative Than Men? Science, 317, 82.
Oller, D. K., Caskey, M., Yoo, H., Bene, E. R., Jhang, Y., Lee, C.-C., . . . Vohr, B. (2019). Preterm and full term infant vocalization and the origin of language. Scientific
Oller, D. K., Griebel, U., Iyer, S. N., Jhang, Y., Warlaumont, A. S., Dale, R., & Call, J. (2019). Language origin seen in spontaneous and interactive vocal rate of human
and bonobo infants. Frontiers Psychology, 10(729). https://doi.org/https://doi.org/10.3389/fpsyg.2019.00729
Oller, D. K., Ramsay, G., Long, H. L., & Griebel, U. (2021). Protophones, the precursors to speech, dominate the human infant vocal landscape. Philosophical
Transactions of the Royal Society B: Biological Sciences, 376(1836), 20200255. https://doi.org/doi:10.1098/rstb.2020.0255
Department of Human Evolutionary Biology, Harvard University.
Sunday September 10th (9 pm Perth West Australian)
Why wading in australopithecines makes sense as a foraging adaptation.
Much like Williams et al. (2023: African apes and the evolutionary history of orthogrady and bipedalism, Yearbook of Physical Anthropology 181: 58-80), I infer that the LCA of australopiths and African apes was a form of African ape that was so similar to chimpanzees, bonobos and gorillas that it had features found in common among those species. This means that the LCA was a knuckle-walking forest-dwelling ape that ate ripe fruits when possible. In the absence of sufficient ripe fruits, the fallback foods that the LCA relied on finding were soft, wet, non-toxic, fermentable vegetation in the form of young leaves and stems from particular tree and herb species. Late Miocene expansions and contractions of the equatorial African forests must have left a population of the LCA in a habitat with inadequate forest foods. Because digestive systems are highly conservative, the possible range of novel fallback diets was limited. For instance early hominin fallback diets cannot reasonably be expected to have focused on fruits, seeds, marine animals, terrestrial invertebrates, grass blades or meat. Differences in teeth between hominins and African apes are consistent, instead, with hominins adapting to eating starchy storage organs (roots, rhizomes etc). The abundance of suitable storage organs is highest and most predictable under shallow water, where they have often been recorded as important foods for humans as well as baboons. This suggests that bipedal locomotion could have evolved in australopiths in response to the need to wade in shallow, low-energy water to collect under-water storage organs (UWSOs). In favor of this hypothesis, since all African apes can wade, the LCA was presumably pre-adapted for wading. Against it, there is no evidence that differences in locomotor anatomy between australopithecines and African apes would have made australopithecines more efficient or more effective as forager-waders. To test the forager-wader hypothesis, therefore, we need to reconstruct whether australopithecines would have been better at wading than apes, and if so, how. This question does not yet appear to have been investigated in detail.
Richard Wrangham is a distinguished British primatologist and anthropologist renowned for his influential contributions to understanding human evolution and behavior. Serving as a professor at Harvard University, Wrangham's research has centered on primate behavior, with a particular focus on chimpanzees. His groundbreaking work extends to the realm of human evolution, where he has explored the impact of cooking on shaping the trajectory of Homo sapiens.
Among Wrangham's most notable publications, "Catching Fire: How Cooking Made Us Human," proposes a compelling hypothesis that cooking food revolutionized human evolution. By making food more easily digestible and energetically rewarding, cooking allowed our ancestors to allocate less time to chewing and foraging, enabling more energy-intensive activities like brain development and social interactions. This perspective challenges traditional theories about human evolution.
With his extensive fieldwork experience, including research at the Kibale Chimpanzee Project in Uganda, Wrangham has also enriched our comprehension of primate social dynamics and behaviors. He has received several awards for his scholarly achievements, emphasizing his significant role in both primatology and anthropology. Wrangham's multifaceted contributions continue to shape our understanding of the deep-rooted connections between human and primate behavior, as well as the pivotal role that cooking played in the development of our species.
World renowned anthropologist/primatologist, Richard Wrangham, shows how the earliest bipedal hominids could have survived times of aridity in wetland refugia. He provides a very impressive body of ecological evidence showing how rich savannah microhabitat wetlands (or "wet savannahs") are in terms of biomass, and asks if wading through such wetlands could consequently have been a significant component in the early evolution of hominid bipedalism.
Sunday August 13th (11 pm Perth West Australian)
Most species who communicate vocally have genetically innate calls that can be modified very little. Vocal learning and vocal flexibility can be found only in very few groups in the animal kingdom. Interestingly, we find these vocal learners amongst the birds, bats, marine mammals, and one amongst the primates – Homo sapiens. In this talk I want to explore the hypothesis that flight and an aquatic lifestyle offered an opportunity to evolve the neuronal and cognitive basis for learned vocalizations – namely the refined conscious control of the valve mechanisms that modulate the pressures of air flow during breathing. Furthermore, the evolution of vocal language would have been impossible without these conscious control mechanisms. Since many human traits (upright gait, hairlessness, subcutaneous fat layers etc) point to an extended period of living in a waterside habitat, in which humans gathered their food mostly in the water through wading, swimming and diving, it might explain why humans – in contrast to all the other primates – were able to vocalize flexibly and to learn to imitate and create new vocalizations.
I will also offer a hypothesis about why certain flying or swimming species evolved flexible vocalizations while others did not. We propose that the necessity of vocal fitness signaling in altricial offspring (chicks. pups, cubs, etc) to convince their parents that they are worth necessary investment created the evolutionary pressure for increased vocal displays (“babbling”) which can be found in many species who also use vocal fitness displays in adulthood during mating to either impress females or to deter male competition. This claim for vocal fitness signaling is also supported by evidence of extensive vocal displays in the human infant during early development.
Potted Bio: Dr. Ulrike Griebel
Faculty affiliate, The University of Memphis, Institute for Intelligent Systems, FedEx Institute of Technology Memphis, 365 Innovation DriveMemphis, TN 38152, USA
Adjunct faculty, School of Communication Sciences and Disorders, The University of Memphis
Member of the Konrad Lorenz Institute for Evolution and Cognition Research, Klosterneuburg, Austria
I am interested in evolution, cognition and communication in general, currently working on communication in primates. I am specially interested in theoretical aspects of communication and the comparison of animal communication systems with human communication and the evolution of language.
Ulrike Griebel investigates the peculiar phenomenon of vocal learning in the animal world, identifying various examples its broad phylogeny particularly within birds and aquatic mammals. Among the primates, we humans are the only ones that can do this. The search for common threads among these disparate species is outlined after which Ulrike ends on the fitness signalling hypothesis, that infant babbling may have been adaptive as an encouragement for further parental attention and investment
Here are some papers Ulrike and her colleagues published on the subject of her talk.
Sunday July 9th (8:30 pm Perth West Australian)
Dr Colin Hendrie is a Senior Lecturer (Associate Professor) in the Department of Psychology, University of Leeds, UK. Leeds is a large Redbrick university in the north of England and one of the elite Russell Group of UK universities. Colin studied at the universities of Middlesex and Aberdeen and gained his PhD from the University of Bradford. His main interest is in ethology, where he has applied this approach to a broad range of species, from gulls to humans. He is a Fellow of the Linnean Society, a member of the ethics committee of the Association for the Study of Animal Behaviour and currently editor-in-chief of 'Human Ethology', the official journal of the International Society for Human Ethology. Colin first became interested in the Waterside/Aquatic Ape Hypothesis whilst an undergraduate and has sought to enthuse new generations by incorporating this into his own undergraduate teaching.
Colin Hendrie, Dept Psychology, University of Leeds, UK
Abstract of the Talk: Was Man More Aquatic in the Past?... Yes.
Humans have no close living relatives and so it is of interest to students of human evolution and behaviour to try and model the characteristics of the last common ancestor (LCA) of humans and chimpanzees. This can be done by examining similarities in the behaviour of these species and also by considering their behavioural differences. This analysis indicates that the LCA was a self-aware, tool-using, hunter-gathering, hand-assisted arboreal biped. It is suggested that the human line’s most likely point of origin was in the flooded/swamp forests of what became the Congo basin during the mid-to-late Miocene. It is proposed that the development of this basin created the conditions for the LCA line to divide based on propensity to engage with water and that this is still reflected in the behaviour of chimpanzees and humans today.
Colin Hendrie gives a psychologist/ethologist’s angle on waterside hypotheses of human evolution. With a beautiful presentation of evidence-based arguments based on great ape behavioural, genetics, parasitology, ecology and paleogeology he makes a strong case for a Congo-origin for humanity and the evolution of bipedalism.
Sunday June 11th (9pm Perth West Australian)
Despite a few notable and vocal proponents speaking out in favour of it, the Wading hypothesis of Hominid Bipedal Origins is still largely ignored by the field of biological anthropology.
When Algis returned to academia to try to find out why, over 20 years ago he decided to take on one of the strongest criticisms against the so-called "aquatic ape hypothesis" that the methodology of its proponents did not practice the scientific method.
So, both his Masters thesis at UCL and his PhD at UWA were written in a strictly Popperian framework of trying to test falsifiable predictions.
As Algis will show, all the tests have passed so far - so there is no good reason why this idea still ignored even today - only very bad ones.
Algis addresses perhaps the only valid reason the so-called "aquatic ape theory" has been ignored so much by the field of biological anthropology - a lack of attention to the scientific method.
Here, Algis describes his Masters and PhD theses which were based upon the hypothetico-deductive method.
Here is the PowerPoint file Algis used in his presentation and a few other supporting files he showed or discussed.
Sunday April 7th 2023 (3pm Belgian Time; 9pm Perth West Australian)
Marc will discusses the importance of plate tectonics in understanding human evolution.
It will comprise of two main subjects:
1) How is it possible that a self-declared "science" (traditional
paleo-anthropology) made four incredible mistakes:
- bipedalism does not define human ancestry: early-Miocene Hominoidea
were already bipedal waders-climbers in swamp forests,
- we did not evolve as Plio-Pleistocene savanna-dwellers, and even less
as savanna runners (endurance-running nonsense),
- we did not come from Africa (out-of-Africa dogma), at best our
late-Miocene ancestors lived in swamp forests of the Red Sea,
- we did not have australopithecine ancestors, such as Lucy:
australopiths were more closely related to Pan or Gorilla.
2) Hypothesis: Were most or all hominoid splittings caused by plate
- Cercopithecoidea/Hominoidea 30 or 25 Ma: islands and peninsulas of
India approaching southern Asia?
- lesser/great apes c 20 Ma: the Indian subcontinent further underneath
- pongids/hominids c 15 Ma: the Mesopotamian Seaway Closure?
- Gorilla/Homo-Pan 8 or 7 Ma: the incipient northern-African Rift
- Pan/Homo 5.33 Ma: the Zanclean mega-flood opening the Red Sea into the
Marc outlines how understanding plate tectonics may help unravel some of the peculiarities of hominoid (ape) evolution.