Urinary Testosterone Metabolite Levels in Bonobos: A Comparison with Chimpanzees in Relation to Social System

Sannen, Adinda; Heistermann, Michael; Elsacker, Linda Van; Möhle, U.; Eens, Marcel

doi:10.1163/156853903322149504

Cited by 30 publications

(23 citation statements)

References 37 publications

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“…Contrarily, females mature later than males, and the youngest bonobo mother in captivity was 8 years old at the time of birth. Moreover, testosterone levels in mature females are much lower than in males, as is also demonstrated in this study [discussed in Sannen et al, 2003]; hence, testosterone levels probably increase less steeply and for a shorter period compared to males.…”

Section: Discussionsupporting

confidence: 82%

Urinary Testosterone Metabolite Levels in Captive Bonobos: Relationship with Age

Sannen

Elsacker²,

Eens³

et al. 2004

IJFP

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Section: Discussionsupporting

confidence: 82%

Urinary Testosterone Metabolite Levels in Captive Bonobos: Relationship with Age

Sannen

Elsacker²,

Eens³

et al. 2004

IJFP

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“…As with cortisol, we began by analyzing anticipatory effects, then moved to posttest effects. For testosterone we performed separate analyses by sex, given the known differences in testosterone levels between males and females in humans and other apes, and the prediction from the human literature and our cortisol results that the effects on this hormone would be more pronounced in males (11,39). Thus for testosterone, all GLM analyses had individual as a within-subject factor and species and outcome as between-subject factors.…”

mentioning

confidence: 99%

Differential changes in steroid hormones before competition in bonobos and chimpanzees

Wobber

Hare

Maboto

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

122

100

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A large body of research has demonstrated that variation in competitive behavior across species and individuals is linked to variation in physiology. In particular, rapid changes in testosterone and cortisol during competition differ according to an individual's or species' psychological and behavioral responses to competition. This suggests that among pairs of species in which there are behavioral differences in competition, there should also be differences in the endocrine shifts surrounding competition. We tested this hypothesis by presenting humans' closest living relatives, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), with a dyadic food competition and measuring their salivary testosterone and cortisol levels. Given that chimpanzees and bonobos differ markedly in their food-sharing behavior, we predicted that they would differ in their rapid endocrine shifts. We found that in both species, males showed an anticipatory decrease (relative to baseline) in steroids when placed with a partner in a situation in which the two individuals shared food, and an anticipatory increase when placed with a partner in a situation in which the dominant individual obtained more food. The species differed, however, in terms of which hormone was affected; in bonobo males the shifts occurred in cortisol, whereas in chimpanzee males the shifts occurred in testosterone. Thus, in anticipation of an identical competition, bonobo and chimpanzee males showed differential endocrine shifts, perhaps due to differences in perception of the situation, that is, viewing the event either as a stressor or a dominance contest. In turn, common selection pressures in human evolution may have acted on the psychology and the endocrinology of our competitive behavior.A cross species, including humans, males engaged in competition tend to show acute shifts in their levels of steroid hormones, such as testosterone and cortisol. These hormones change in a matter of minutes surrounding a competitive event, in anticipation of the competition and in response to its outcome (1, 2). In humans, men normally demonstrate an increase in cortisol before competition (3, 4). After the competition male winners tend to maintain their testosterone levels, whereas male losers' testosterone decreases (5, 6). In other animals, competing males show similar rapid changes in glucocorticoids and testosterone, since these hormones are thought to mediate energy allocation toward mating effort across species (7-10). Because competition for overt markers of status and mating opportunities is more relevant to males, these effects are less consistent in females (11)(12)(13)(14). Beyond these typical patterns, there is also high variability within and between species in the nature of the hormonal shifts surrounding competition that may be shaped by the psychology underlying competitive behavior.Two main psychological factors have been implicated in governing the endocrine changes surrounding competition within and between species: implicit power motive and coping styl...

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“…This relationship is strongest in the great apes, proving that it is phylogenetically deep enough to predict T levels in fossil hominins. Baseline androgen levels in primate species, as well as dimorphism between the sexes within species, are highly predictive of social systems (e.g., Sannen et al 2003). In particular, it has been observed that increased T accompanies heightened intergroup aggression.…”

Section: Rethinking a Pleistocene Passage To India: New Lithic Evidenmentioning

confidence: 99%

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2013

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Orrorin tugenensis (Kenya, ca. 6 Ma) is one of the earliest putative hominins in the fossil record. The Orrorin hypodigm includes three partial femora, with one of them-BAR 1002'00-preserving most of its proximal morphology and exhibiting inferred adaptations for terrestrial bipedalism. This specimen was originally described as being very human-like, even more so than later hominins, although subsequent multivariate analyses showed that it actually shares a distinctive shape with australopiths. However, some traits of this femur (e.g., greater and lesser trochanteric form) recall the morphology seen in earlier Miocene apes. Here we reassess the morphological affinities of BAR 1002'00 using three-dimensional geometric morphometrics (13 coordinates covering functionally meaningful landmarks of the proximal femur), within an extensive sample of modern humans, great apes, and hylobatids, as well as with fossil hominins, and-for the first time-Miocene apes. Since Miocene apes have been described by some as monkey-like for certain features, we also included a broad sample of cercopithecoid and platyrrhine monkeys (N of total sample=448). Our multivariate results (based on between-group principal components analysis [bgPCA] and phylogenetic methods) indicate that platyrrhines, cercopithecoids, and hominoids can be reliably distinguished from each other, thereby indicating a strong phylogenetic signal in the shape data (p<0.0001). Our results also demonstrate that Miocene apes are more similar to extant apes than to any extant monkey. A bgPCA focused on hominoids only reveals that BAR 1002'00 displays strong shape affinities with the earlier Miocene apes, being intermediate between them and some australopiths. Extant great apes, and especially chimpanzees and bonobos, display a distinct and probably derived morphology. These results suggest that some Miocene apes could closely approximate the proximal femoral anatomy of the last common ancestor of hominins and African apes. Orrorin apparently preserves aspects of this ancestral shape. The appearance of engraved ostrich eggshell (OES) canteens around 65 ka in southern Africa, and beads by 50-45 ka in eastern and southern Africa, represent significant milestones in the evolution of modern human technology and symbolic behavior. Methods for describing OES artifacts, thermal alteration, and criteria for identifying natural damage and use-wear on canteens are not systematically applied, hindering comparative analyses. We present a preliminary descriptive analysis system for OES using >40 ka and mid-Holocene Later Stone Age (LSA) OES assemblages from Enkapune Ya Muto Rockshelter, Kenya. Comparison to the >40 ka bead assemblage from Border Cave, South Africa, shows that the earliest LSA beads in both regions have irregular faceted perimeters from chipping and grinding on flat surfaces. Mid-Holocene beads have more symmetric rounded perimeters, indicating grinding in grooved stones. Kalahari foragers often recycled OES canteen fragments for bead manufacture. Beaded artifacts we...

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Urinary Testosterone Metabolite Levels in Bonobos: A Comparison with Chimpanzees in Relation to Social System

Cited by 30 publications

References 37 publications

Urinary Testosterone Metabolite Levels in Captive Bonobos: Relationship with Age

Urinary Testosterone Metabolite Levels in Captive Bonobos: Relationship with Age

Differential changes in steroid hormones before competition in bonobos and chimpanzees

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