Cochlear shape distinguishes southern African early hominin taxa with unique auditory ecologies

AbstractInsights into potential differences among the bony labyrinths of Plio-Pleistocene hominins may inform their evolutionary histories and sensory ecologies. We use four recently-discovered bony labyrinths from the site of Kromdraai to significantly expand the sample for Paranthropus robustus. Diffeomorphometry, which provides detailed information about cochlear shape, reveals size-independent differences in cochlear shape between P. robustus and Australopithecus africanus that exceed those among modern humans and the African apes. The cochlea of P. robustus is distinctive and relatively invariant, whereas cochlear shape in A. africanus is more variable, resembles that of early Homo, and shows a degree of morphological polymorphism comparable to that evinced by modern species. The curvature of the P. robustus cochlea is uniquely derived and is consistent with enhanced sensitivity to low-frequency sounds. Combined with evidence for selection, our findings suggest that sound perception shaped distinct ecological adaptations among southern African early hominins.

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Seven Steps in the Evolution of the Human Imagination

Imaginative Minds ◽

10.5871/bacad/9780197264195.003.0001 ◽

2007 ◽

Author(s):

STEVEN MITHEN

Keyword(s):

Cultural Change ◽

Homo Sapiens ◽

Brain Size ◽

Modern Human ◽

Clear Picture ◽

Modern Humans ◽

Creative Imagination ◽

African Apes ◽

Ways Of Thinking ◽

Forms Of Knowledge

The modern human is a product of six million years of evolution wherein it is assumed that the ancestor of man resembles that of a chimpanzee. This assumption is based on the similarities of the ape-like brain size and post-cranial characteristics of the earliest hominid species to chimpanzees. Whilst it is unclear whether chimpanzees share the same foresight and contemplation of alternatives as with humans, it is nevertheless clear that chimpanzees lack creative imagination — an aspect of modern human imagination that sets humanity apart from its hominid ancestors. Creative imagination pertains to the ability to combine different forms of knowledge and ways of thinking to form creative and novel ideas. This chapter discusses seven critical steps in the evolution of the human imagination. These steps provide a clear picture of the gradual emergence of creative imagination in humans from their primitive origins as Homo sapiens some 200,000 years ago. This chronological evolution of the imaginative mind of humans involves both biological and cultural change that began soon after the divergence of the two lineages that led to modern humans and African apes.

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Tools to tipple: ethanol ingestion by wild chimpanzees using leaf-sponges

Royal Society Open Science ◽

10.1098/rsos.150150 ◽

2015 ◽

Vol 2 (6) ◽

pp. 150150 ◽

Cited By ~ 18

Author(s):

Kimberley J. Hockings ◽

Nicola Bryson-Morrison ◽

Susana Carvalho ◽

Michiko Fujisawa ◽

Tatyana Humle ◽

...

Keyword(s):

Alcoholic Beverage ◽

Genetic Mutation ◽

Ethanol Ingestion ◽

Last Common Ancestor ◽

Modern Humans ◽

African Apes ◽

Raphia Hookeri ◽

Plastic Containers ◽

Voluntary Ethanol Consumption

African apes and humans share a genetic mutation that enables them to effectively metabolize ethanol. However, voluntary ethanol consumption in this evolutionary radiation is documented only in modern humans. Here, we report evidence of the long-term and recurrent ingestion of ethanol from the raffia palm ( Raphia hookeri, Arecaceae) by wild chimpanzees ( Pan troglodytes verus ) at Bossou in Guinea, West Africa, from 1995 to 2012. Chimpanzees at Bossou ingest this alcoholic beverage, often in large quantities, despite an average presence of ethanol of 3.1% alcohol by volume (ABV) and up to 6.9% ABV. Local people tap raffia palms and the sap collects in plastic containers, and chimpanzees use elementary technology—a leafy tool—to obtain this fermenting sap. These data show that ethanol does not act as a deterrent to feeding in this community of wild apes, supporting the idea that the last common ancestor of living African apes and modern humans was not averse to ingesting foods containing ethanol.

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A Novel Sensor Prototype with Enhanced and Adaptive Sensitivity Based on Negative Stiffness Mechanism

Sensors ◽

10.3390/s20164644 ◽

2020 ◽

Vol 20 (16) ◽

pp. 4644

Author(s):

Lijun Liu ◽

Yongzhong Nie ◽

Ying Lei

Keyword(s):

Low Frequency ◽

High Sensitivity ◽

Negative Stiffness ◽

Micro Electro Mechanical Systems ◽

Enhanced Sensitivity ◽

Landslide Hazards ◽

Negative Stiffness Mechanism ◽

Low Sensitivity ◽

Electric Filed ◽

Design And Manufacture

Loess–mudstone/soil-rock interfacial landslide is one of the prominent landslide hazards that occurs in soil rock contacting zones. It is necessary to develop sensors with high sensitivity to weak and low frequency vibrations for the early warning of such interfacial landslides. In this paper, a novel monitoring sensor prototype with enhanced and adaptive sensitivity is developed for this purpose. The novelty of the sensitive sensor is based on the variable capacitances and negative stiffness mechanism due to the electric filed forces on the vibrating plate. Owing to the feedback control of adjustable electrostatic field by an embedded micro controller, the sensor has adaptive amplification characteristics with high sensitivity to weak and low frequency input and low sensitivity to high input. The design and manufacture of the proposed sensor prototype by Micro-Electro-Mechanical Systems (MEMS) with proper packaging are introduced. Post-signal processing is also presented. Some preliminary testing of the prototype and experimental monitoring of sand interfacial slide which mimics soil–rock interfacial landslide were performed to demonstrate the performance of the developed sensor prototype with adaptive amplification and enhanced sensitivity.

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Hominin Postcranial Remains from Sterkfontein, South Africa, 1936-1995

10.1093/oso/9780197507667.001.0001 ◽

2020 ◽

Keyword(s):

South Africa ◽

Human Evolution ◽

International Workshop ◽

Gauteng Province ◽

Australopithecus Africanus ◽

Postcranial Remains ◽

Early Hominin ◽

To Come ◽

Answering Questions ◽

Early Human

The excavations at Sterkfontein Cave, Gauteng Province, South Africa, have yielded one of the largest collections of postcranial fossils of any hominin site. These fossils remain relatively unstudied, and few published comprehensively, despite the enormous potential of these fossils for answering questions about Australopithecus africanus paleobiology, early hominin variation, and early human evolution. This volume presents photographs, anatomical descriptions and analyses for all Sterkfontein hominin postcranial fossils that were available for study in 2009, when an international workshop of experts was convened at University of the Witwatersrand to discuss and study this material. The chapters in this volume represent a foundation for further investigations with which to interpret these and other fossils from Sterkfontein, and from all over Africa, that will be recovered in years to come.

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Thoracic vertebral count and thoracolumbar transition in Australopithecus afarensis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1702229114 ◽

2017 ◽

Vol 114 (23) ◽

pp. 6000-6004 ◽

Cited By ~ 11

Author(s):

Carol V. Ward ◽

Thierra K. Nalley ◽

Fred Spoor ◽

Paul Tafforeau ◽

Zeresenay Alemseged

Keyword(s):

Vertebral Column ◽

Cervical Vertebrae ◽

Homo Erectus ◽

Thoracic Vertebrae ◽

Australopithecus Afarensis ◽

Australopithecus Africanus ◽

African Apes ◽

Thoracic Level ◽

Thoracolumbar Transition ◽

Considerable Discussion

The evolution of the human pattern of axial segmentation has been the focus of considerable discussion in paleoanthropology. Although several complete lumbar vertebral columns are known for early hominins, to date, no complete cervical or thoracic series has been recovered. Several partial skeletons have revealed that the thoracolumbar transition in early hominins differed from that of most extant apes and humans. Australopithecus africanus, Australopithecus sediba, and Homo erectus all had zygapophyseal facets that shift from thoracic-like to lumbar-like at the penultimate rib-bearing level, rather than the ultimate rib-bearing level, as in most humans and extant African apes. What has not been clear is whether Australopithecus had 12 thoracic vertebrae as in most humans, or 13 as in most African apes, and where the position of the thoracolumbar transitional element was. The discovery, preparation, and synchrotron scanning of the Australopithecus afarensis partial skeleton DIK-1-1, from Dikika, Ethiopia, provides the only known complete hominin cervical and thoracic vertebral column before 60,000 years ago. DIK-1-1 is the only known Australopithecus skeleton to preserve all seven cervical vertebrae and provides evidence for 12 thoracic vertebrae with a transition in facet morphology at the 11th thoracic level. The location of this transition, one segment cranial to the ultimate rib-bearing vertebra, also occurs in all other early hominins and is higher than in most humans or extant apes. At 3.3 million years ago, the DIK-1-1 skeleton is the earliest example of this distinctive and unusual pattern of axial segmentation.

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Transmastoid reshaping of the sigmoid sinus: preliminary study of a novel surgical method to quiet pulsatile tinnitus of an unrecognized vascular origin

Journal of Neurosurgery ◽

10.3171/2015.6.jns15961 ◽

2016 ◽

Vol 125 (2) ◽

pp. 441-449 ◽

Cited By ~ 22

Author(s):

Chong Sun Kim ◽

So Young Kim ◽

Hyunseok Choi ◽

Ja-Won Koo ◽

Shin-Young Yoo ◽

...

Keyword(s):

Bone Cement ◽

Rating Scales ◽

Case Series ◽

Low Frequency ◽

Sigmoid Sinus ◽

Pathophysiological Mechanism ◽

Pulsatile Tinnitus ◽

Sound Perception ◽

Surgical Method ◽

Imaging Results

OBJECTIVE A dominant sigmoid sinus with focal dehiscence or thinning (DSSD/T) of the overlying bony wall is a commonly encountered, but frequently overlooked, cause of vascular pulsatile tinnitus (VPT). Also, the pathophysiological mechanism of sound perception in patients with VPT remains poorly understood. In the present study, a novel surgical method, termed transmastoid SS-reshaping surgery, was introduced to ameliorate VPT in patients with DSSD/T. The authors reviewed a case series, analyzed the surgical outcomes, and suggested the pathophysiological mechanism of sound perception. The theoretical background underlying VPT improvement after transmastoid SS-reshaping surgery was also explored. METHODS Eight patients with VPT that was considered attributable to DSSD/T underwent transmastoid SS-reshaping surgery between February 2010 and February 2015. The mean postoperative follow-up period was 9.5 months (range 4–13 months). Transmastoid SS-reshaping surgery featured simple mastoidectomy, partial compression of the SS using harvested cortical bone chips, and reinforcement of the bony SS wall with bone cement. Perioperative medical records, imaging results, and audiological findings were comprehensively reviewed. RESULTS In 7 of the 8 patients (87.5%), the VPT abated immediately after surgery. Statistically significant improvements in tinnitus loudness and distress were evident on numeric rating scales. Three patients with preoperative ipsilesional low-frequency hearing loss exhibited postoperative improvements in their low-frequency hearing thresholds. No major postoperative complications were encountered except in the first subject, who experienced increased intracranial pressure postoperatively. This subsided after a revision operation for partial decompression of the SS. CONCLUSIONS Transmastoid SS-reshaping surgery may be a good surgical option in patients with DSSD/T, a previously unrecognized cause of VPT. Redistribution of severely asymmetrical blood flow, reinforcement of the bony SS wall with bone cement to reconstruct a soundproof barrier, and disconnection of a problematic sound conduction route via simple mastoidectomy silence VPT.

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Early hominin auditory capacities

Science Advances ◽

10.1126/sciadv.1500355 ◽

2015 ◽

Vol 1 (8) ◽

pp. e1500355 ◽

Cited By ~ 15

Author(s):

Rolf Quam ◽

Ignacio Martínez ◽

Manuel Rosa ◽

Alejandro Bonmatí ◽

Carlos Lorenzo ◽

...

Keyword(s):

Middle Ear ◽

Short Range ◽

Vocal Communication ◽

Sensory Ecology ◽

Life Forms ◽

Auditory Pattern ◽

Australopithecus Africanus ◽

Stapes Footplate ◽

Past Life ◽

Early Hominin

Studies of sensory capacities in past life forms have offered new insights into their adaptations and lifeways. Audition is particularly amenable to study in fossils because it is strongly related to physical properties that can be approached through their skeletal structures. We have studied the anatomy of the outer and middle ear in the early hominin taxaAustralopithecus africanusandParanthropus robustusand estimated their auditory capacities. Compared with chimpanzees, the early hominin taxa are derived toward modern humans in their slightly shorter and wider external auditory canal, smaller tympanic membrane, and lower malleus/incus lever ratio, but they remain primitive in the small size of their stapes footplate. Compared with chimpanzees, both early hominin taxa show a heightened sensitivity to frequencies between 1.5 and 3.5 kHz and an occupied band of maximum sensitivity that is shifted toward slightly higher frequencies. The results have implications for sensory ecology and communication, and suggest that the early hominin auditory pattern may have facilitated an increased emphasis on short-range vocal communication in open habitats.

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Sacrum morphology supports taxonomic heterogeneity of Australopithecus africanus at Sterkfontein Member 4

10.21203/rs.3.rs-72859/v1 ◽

2020 ◽

Author(s):

Cinzia Fornai ◽

Viktoria Krenn ◽

Philipp Mitteröcker ◽

Nicole Webb ◽

Martin Haeusler

Keyword(s):

South Africa ◽

Sexual Dimorphism ◽

Geometric Morphometrics ◽

Single Species ◽

Modern Humans ◽

Male Adult ◽

Australopithecus Africanus ◽

Human Sample ◽

Quantitative Assessments

Abstract The presence of multiple Australopithecus species at Sterkfontein Member 4, South Africa (2.07 to 2.61 Ma) is highly contentious. Quantitative assessments of craniodental and postcranial variability remain inconclusive. Using geometric morphometrics, we compared the sacrum of the small-bodied, presumed female subadult Australopithecus africanus skeleton Sts 14 and the large, alleged male adult StW 431 against a geographically diverse sample of modern humans, and two species for each of the genera Gorilla, Pan and Pongo. The probabilities of sampling morphologies as distinct as Sts 14 and StW 431 from a single species ranged from 1.3 to 2.5% for the human sample, and from 0.0 to 4.5% for the ape sample, depending on the analysis performed. Neither differences in developmental or geologic age nor sexual dimorphism could account for the differences between StW 431 and Sts 14 sacra. These findings support earlier claims of taxonomic heterogeneity at Sterkfontein Member 4.

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Insertion sites in manual proximal phalanges of African apes and modern humans

American Journal of Physical Anthropology ◽

10.1002/ajpa.24127 ◽

2020 ◽

Vol 173 (3) ◽

pp. 556-567

Author(s):

Ana Bucchi ◽

Javier Luengo ◽

Antonietta Del Bove ◽

Carlos Lorenzo

Keyword(s):

Modern Humans ◽

African Apes ◽

Insertion Sites

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Behavioural responses of the European spiny lobster, Palinurus elephas (Fabricius, 1787), to conspecific and synthetic sounds

Crustaceana ◽

10.1163/15685403-00003430 ◽

2015 ◽

Vol 88 (5) ◽

pp. 523-540 ◽

Cited By ~ 7

Author(s):

G. de Vincenzi ◽

F. Filiciotto ◽

V. Maccarrone ◽

S. Mazzola ◽

G. Buscaino

Keyword(s):

Spiny Lobster ◽

Low Frequency ◽

Linear Sweep ◽

Sound Stimulation ◽

Sound Perception ◽

Acoustic Stimuli ◽

Intraspecific Communication ◽

Audio Video ◽

Combined Data ◽

Palinurus Elephas

This study examined the effects of three different acoustic stimuli on the behaviour of the European spiny lobster,Palinurus elephas(Fabricius, 1787). Twenty male and 20 female lobsters were exposed to: a low-frequency linear sweep tone (0.1-20 kHz), a high-frequency linear sweep tone (20-80 kHz), conspecific sounds (rasp: train of wideband pulses), and no sound stimulation (control). After a habituation period, lobsters were audio-video recorded for 30 min. Tail flipping, sound emissions, distance moved, mobility, velocity and movement were recorded. Differences between the males and females in the rasp playback condition were observed, with the females having highest values of the behaviours under study. Moreover, when analysing the male and female combined data we found that exposure to synthetic stimuli did not produce any significant variations. Finally, it can be assumed that there is: a capacity for rasp sound perception, and a significant role for these pulses in the intraspecific communication ofP. elephas.

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