Northern bald ibises follow others’ gaze into distant space but not behind barriers

Gaze following is the ability to use the visual orientation of others as a trigger to look in the same direction. Thereby, animals may either align their head and eye orientation with others (gaze following into distant space) or may even reposition themselves to look behind barriers impairing their perception (geometrical gaze following). It has been proposed that these two different modes are functionally and cognitively distinct, but experimental evidence for this claim is lacking. We here, to our knowledge, demonstrate for the first time, that adult animals may be capable of following gaze into distant space, but not geometrically around barriers. We tested Northern bald ibises ( Geronticus eremita ) for their ability to follow a conspecific's gaze in two standard tasks. The birds readily looked up after seeing a model bird looking up; however, when seeing a model looking behind a barrier, they responded by looking at the barrier instead of walking around. These findings are in stark contrast to results obtained with great apes and corvids and provide the first experimental evidence, to our knowledge, for cognitive differences in gaze following tasks.

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Experimental evidence for yawn contagion in orangutans (Pongo pygmaeus)

Scientific Reports ◽

10.1038/s41598-020-79160-x ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Evy van Berlo ◽

Alejandra P. Díaz-Loyo ◽

Oscar E. Juárez-Mora ◽

Mariska E. Kret ◽

Jorg J. M. Massen

Keyword(s):

Experimental Evidence ◽

Common Ancestor ◽

Great Apes ◽

Pongo Pygmaeus ◽

Last Common Ancestor ◽

Contagious Yawning ◽

Proximate Mechanism ◽

Social Species ◽

Ultimate Causation

AbstractYawning is highly contagious, yet both its proximate mechanism(s) and its ultimate causation remain poorly understood. Scholars have suggested a link between contagious yawning (CY) and sociality due to its appearance in mostly social species. Nevertheless, as findings are inconsistent, CY’s function and evolution remains heavily debated. One way to understand the evolution of CY is by studying it in hominids. Although CY has been found in chimpanzees and bonobos, but is absent in gorillas, data on orangutans are missing despite them being the least social hominid. Orangutans are thus interesting for understanding CY’s phylogeny. Here, we experimentally tested whether orangutans yawn contagiously in response to videos of conspecifics yawning. Furthermore, we investigated whether CY was affected by familiarity with the yawning individual (i.e. a familiar or unfamiliar conspecific and a 3D orangutan avatar). In 700 trials across 8 individuals, we found that orangutans are more likely to yawn in response to yawn videos compared to control videos of conspecifics, but not to yawn videos of the avatar. Interestingly, CY occurred regardless of whether a conspecific was familiar or unfamiliar. We conclude that CY was likely already present in the last common ancestor of humans and great apes, though more converging evidence is needed.

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Quid facit cum psalterio Horatius? (Hier. ep. 22,29,7)

Vigiliae Christianae ◽

10.1163/15700720-12341480 ◽

2021 ◽

Vol 75 (4) ◽

pp. 389-454

Author(s):

Barbara Feichtinger

Keyword(s):

Stark Contrast ◽

Comprehensive Classification ◽

First Time

Abstract Using the example of Epistula 3 Jerome’s citation technique is analyzed in detail. For this purpose, a comprehensive classification grid of intertextual references is introduced for the first time, which allows a systematization of the narrative examination of citations and allusions. Thus, not only differences in the use of Bible verses and quotations of classics can be highlighted transparently but also a (radical) syntactic, structural, and semantic incorporation of biblical and classic pre-texts by Jerome’s text can be substantiated. In stark contrast to former, rather negative verdicts on Jerome’s “cento style” and semantic incoherences in his writing, this approach is capable of showing a high functionality and authority in Jerome’s strategy of referencing, which shapes the narrative of the friendship letter not only aesthetically but also significantly helps to constitute its semantics.

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From action to language: comparative perspectives on primate tool use, gesture and the evolution of human language

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2011.0295 ◽

2012 ◽

Vol 367 (1585) ◽

pp. 4-9 ◽

Cited By ~ 24

Author(s):

James Steele ◽

Pier Francesco Ferrari ◽

Leonardo Fogassi

Keyword(s):

Experimental Evidence ◽

Tool Use ◽

Close Association ◽

Great Apes ◽

Human Action ◽

Human Language ◽

Special Issue ◽

Neural Representations ◽

Language Representation ◽

Fossil Hominins

The papers in this Special Issue examine tool use and manual gestures in primates as a window on the evolution of the human capacity for language. Neurophysiological research has supported the hypothesis of a close association between some aspects of human action organization and of language representation, in both phonology and semantics. Tool use provides an excellent experimental context to investigate analogies between action organization and linguistic syntax. Contributors report and contextualize experimental evidence from monkeys, great apes, humans and fossil hominins, and consider the nature and the extent of overlaps between the neural representations of tool use, manual gestures and linguistic processes.

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Growth of noncrystallographic dendrites

Journal of Materials Research ◽

10.1557/jmr.1992.1987 ◽

1992 ◽

Vol 7 (8) ◽

pp. 1987-1989 ◽

Cited By ~ 6

Author(s):

L.M. Fabietti ◽

J.A. Sekhar

Keyword(s):

Steady State ◽

Experimental Evidence ◽

Quantitative Characterization ◽

Steady State Growth ◽

State Growth ◽

First Time

First time experimental evidence is presented for the steady state growth of dendrites away from their normal crystallographic growth directions. The evidence is shown for transparent dendrites in the succinonitrile system, which are induced to grow along wetting surfaces. A method for the quantitative characterization of the tips of such dendrites is described and the differences in the secondary arm formation between off-axis and regular dendrites are recorded. The scientific and technological implications of this finding are examined.

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An Engineering Approach to the Design of Laminarizing Nozzle Flows

Journal of Basic Engineering ◽

10.1115/1.3425584 ◽

1972 ◽

Vol 94 (4) ◽

pp. 897-903 ◽

Cited By ~ 5

Author(s):

J. L. Nash-Webber ◽

G. C. Oates

Keyword(s):

Experimental Evidence ◽

Engineering Design ◽

Prediction Method ◽

Critical Survey ◽

Intensive Research ◽

The Past ◽

Prediction Scheme ◽

First Time ◽

Prediction Criteria ◽

Nozzle Flows

Despite intensive research into laminarization over the past twenty years, there has resulted hitherto no prediction method suitable for ab intio engineering design applications. Following a critical survey of currently proposed prediction criteria, this paper presents experimental evidence for a new prediction scheme applicable for the first time to compressible adiabatic flows. It is shown that this scheme is readily applicable for engineering design purposes. Extension to nonadiabatic flows is discussed.

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BUNDLE BLOCK ADJUSTMENT WITH CONSTRAINED RELATIVE ORIENTATIONS

ISPRS Annals of Photogrammetry Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-annals-v-2-2020-49-2020 ◽

2020 ◽

Vol V-2-2020 ◽

pp. 49-55

Author(s):

E. Maset ◽

L. Magri ◽

I. Toschi ◽

A. Fusiello

Keyword(s):

Empirical Study ◽

Experimental Evidence ◽

Jacobian Matrix ◽

Relative Orientation ◽

Bundle Adjustment ◽

Computational Load ◽

Camera Systems ◽

Bundle Block Adjustment ◽

First Time

Abstract. This paper deals with bundle adjustment with constrained cameras, i.e. where the orientation of certain cameras is expressed relatively to others, and these relative orientations are part of the unknowns. Despite the remarkable interest for oblique multi-camera systems, an empirical study on the effect of enforcing relative orientation constraints in bundle adjustment is still missing. We provide experimental evidence that indeed these constraints improve the accuracy of the results, while reducing the computational load as well. Moreover, we report for the first time in the literature the complete derivation of the Jacobian matrix for bundle adjustment with constrained cameras, to foster other implementations.

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Scleral pigmentation leads to conspicuous, not cryptic, eye morphology in chimpanzees

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1911410116 ◽

2019 ◽

Vol 116 (39) ◽

pp. 19248-19250 ◽

Cited By ~ 3

Author(s):

Juan Olvido Perea-García ◽

Mariska E. Kret ◽

Antónia Monteiro ◽

Catherine Hobaiter

Keyword(s):

Great Apes ◽

Gaze Following ◽

Eye Morphology ◽

Social Cue ◽

Relative Contrast ◽

Perceptual Mechanism ◽

Scleral Pigmentation ◽

Human Specific

Gaze following has been argued to be uniquely human, facilitated by our depigmented, white sclera [M. Tomasello, B. Hare, H. Lehmann, J. Call, J. Hum. Evol. 52, 314–320 (2007)]—the pale area around the colored iris—and to underpin human-specific behaviors such as language. Today, we know that great apes show diverse patterns of scleral coloration [J. A. Mayhew, J. C. Gómez, Am. J. Primatol. 77, 869–877 (2015); J. O. Perea García, T. Grenzner, G. Hešková, P. Mitkidis, Commun. Integr. Biol. 10, e1264545 (2016)]. We compare scleral coloration and its relative contrast with the iris in bonobos, chimpanzees, and humans. Like humans, bonobos’ sclerae are lighter relative to the color of their irises; chimpanzee sclerae are darker than their irises. The relative contrast between the sclera and iris in all 3 species is comparable, suggesting a perceptual mechanism to explain recent evidence that nonhuman great apes also rely on gaze as a social cue.

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Zoonotic Abbreviata caucasica in Wild Chimpanzees (Pan troglodytes verus) from Senegal

Pathogens ◽

10.3390/pathogens9070517 ◽

2020 ◽

Vol 9 (7) ◽

pp. 517 ◽

Cited By ~ 2

Author(s):

Younes Laidoudi ◽

Hacène Medkour ◽

Maria Stefania Latrofa ◽

Bernard Davoust ◽

Georges Diatta ◽

...

Keyword(s):

Pan Troglodytes ◽

Environmental Samples ◽

Great Apes ◽

12S Rrna ◽

Pan Troglodytes Verus ◽

Fecal Matter ◽

Molecular Tool ◽

Routine Diagnosis ◽

First Time

Abbreviata caucasica (syn. Physaloptera mordens) has been reported in human and various non-human primates including great apes. The identification of this nematode is seldom performed and relies on egg characterization at the coproscopy, in the absence of any molecular tool. Following the recovery of two adult females of A. caucasica from the feces of wild Senegalese chimpanzees, morphometric characteristics were reported and new data on the width of the esophagus (0.268–0.287 mm) and on the cuticle structure (0.70–0.122 mm) were provided. The molecular characterization of a set of mitochondrial (cox1, 16S rRNA, 12S rRNA) and nuclear (18S rRNA and ITS2) partial genes was performed. Our phylogenetic analysis indicates for the first time that A. caucasica is monophyletic with Physaloptera species. A novel molecular tool was developed for the routine diagnosis of A. caucasica and the surveillance of Nematoda infestations. An A. caucasica-specific qPCR targeting the 12S gene was assessed. The assay was able to detect up to 1.13 × 10−3 eggs/g of fecal matter irrespective of its consistency, with an efficiency of 101.8% and a perfect adjustment (R2 = 0.99). The infection rate by A. caucasica in the chimpanzee fecal samples was 52.08%. Only 6.19% of the environmental samples were positive for nematode DNA and any for A. caucasica. Our findings indicate the need for further studies to clarify the epidemiology, circulation, life cycle, and possible pathological effects of this infestation using the molecular tool herein developed.

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Implications of A.L. 444-2 for the Taxonomic and Phylogenetic Status of Australopithecus afarensis

The Skull of Australopithecus afarensis ◽

10.1093/oso/9780195157062.003.0009 ◽

2004 ◽

Author(s):

William H. Kimbel ◽

Yoel Rak ◽

Donald C. Johanson ◽

Ralph L. Holloway ◽

Michael S. Yuan

Keyword(s):

Great Apes ◽

Modern Human ◽

Craniofacial Morphology ◽

Single Individual ◽

Australopithecus Afarensis ◽

Adult Individual ◽

The Face ◽

Posterior Parietal ◽

African Great Apes ◽

First Time

A.L. 444-2 is the first specimen to preserve the cranium and mandible of a single adult individual of A. afarensis. Pairing this specimen with A.L. 417-1, which includes a mandible and maxilla, enables us to compare comprehensively the craniofacial morphology of male and female individuals of the species for the first time. The occluded mandibles and maxillae of A.L. 444-2 and A.L. 417-1 reveal a distinctive hominoid snout contour, combining a strongly inclined, convexly sloping nasoalveolar clivus with a relatively upright mandibular symphysis, a straight to slightly rounded anterior symphyseal outline, and an anteriorly placed gnathion. Both A. afarensis specimens feature a very deep mandibular corpus, whose height occupies close to 70% of the orbitoalveolar height of the face. In the African great apes, this value ranges from 36% to 54%, and in modern humans, it is 66%. The high value in humans is due to a short orbitoalveolar region rather than to a deep mandible. A. afarensis appears to share a relatively deep corpus with A. robustus (the only robust species in which the feature can be determined for a single individual) but not with A. africanus. Relative to the calvarial length, the A.L. 444-2 braincase height is apelike, falling between the tall modern human braincase and the low braincase of A. boisei and A. aethiopicus. In A. africanus (Sts. 5) and H. habilis (KNMER 1813) the relative braincase height is like that of A.L. 444-2 and the great apes. According to Le Gros Clark’s (1950) index expressing the height of the calvaria above the roof of the orbit as a percentage of total calvarial height, Sts. 5 and KNM-ER 1813 have tall, “humanlike” braincases, whereas A.L. 444-2, A. boisei, A. aethiopicus, and the African great apes group together with low braincases. In contrast to the rounded, nearly circular midsagittal outline of the chimpanzee calvaria, the posterior parietal/ occipital arc in A.L. 444-2 is steep and deviates anteriorly from the circle. This is also true of the A. boisei calvaria. As expected from the calvarial height comparison, the slope of the A.L. 444-2 frontal squama is smaller than that of A. africanus and H. habilis.

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