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| Author | Cameron, E.Z. | ||||
| Title | Facultative adjustment of mammalian sex ratios in support of the Trivers-Willard hypothesis: evidence for a mechanism | Type | Journal Article | ||
| Year | 2004 | Publication | Proceedings. Biological sciences / The Royal Society | Abbreviated Journal | Proc Biol Sci |
| Volume | 271 | Issue | 1549 | Pages | 1723-1728 |
| Keywords | Age Factors; Animals; Body Constitution; *Evolution; Female; Glucose/metabolism/physiology; Litter Size; Male; Mammals/*physiology; *Models, Biological; Reproduction/physiology; Seasons; Sex Factors; *Sex Ratio; Time Factors | ||||
| Abstract | Evolutionary theory predicts that mothers of different condition should adjust the birth sex ratio of their offspring in relation to future reproductive benefits. Published studies addressing variation in mammalian sex ratios have produced surprisingly contradictory results. Explaining the source of such variation has been a challenge for sex-ratio theory, not least because no mechanism for sex-ratio adjustment is known. I conducted a meta-analysis of previous mammalian sex-ratio studies to determine if there are any overall patterns in sex-ratio variation. The contradictory nature of previous results was confirmed. However, studies that investigated indices of condition around conception show almost unanimous support for the prediction that mothers in good condition bias their litters towards sons. Recent research on the role of glucose in reproductive functioning have shown that excess glucose favours the development of male blastocysts, providing a potential mechanism for sex-ratio variation in relation to maternal condition around conception. Furthermore, many of the conflicting results from studies on sex-ratio adjustment would be explained if glucose levels in utero during early cell division contributed to the determination of offspring sex ratios. | ||||
| Address | Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. ezcameron@zoology.up.ac.za | ||||
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| Language | English | Summary Language | Original Title | ||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0962-8452 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:15306293 | Approved  |
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| Call Number | refbase @ user @ | Serial | 413 | ||
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| Author | Johnson, D.D.P.; Stopka, P.; Knights, S. | ||||
| Title | Sociology: The puzzle of human cooperation | Type | Journal Article | ||
| Year | 2003 | Publication | Nature | Abbreviated Journal | Nature |
| Volume | 421 | Issue | 6926 | Pages | 911-2; discussion 912 |
| Keywords | Altruism; *Cooperative Behavior; Evolution; Humans; *Models, Biological; Punishment; Reward; Risk | ||||
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| Address | Olin Institute for Strategic Studies, Harvard University, Cambridge, Massachusetts 02138, USA. dominic@post.harvard.edu | ||||
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| Language | English | Summary Language | Original Title | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0028-0836 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:12606989 | Approved |
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| Call Number | refbase @ user @ | Serial | 467 | ||
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| Author | Scheffer, M.; van Nes, E.H. | ||||
| Title | Self-organized similarity, the evolutionary emergence of groups of similar species | Type | Journal Article | ||
| Year | 2006 | Publication | Proceedings of the National Academy of Sciences of the United States of America | Abbreviated Journal | Proc. Natl. Acad. Sci. U.S.A. |
| Volume | 103 | Issue | 16 | Pages | 6230-6235 |
| Keywords | Animals; *Competitive Behavior; *Ecosystem; *Evolution; *Models, Biological | ||||
| Abstract | Ecologists have long been puzzled by the fact that there are so many similar species in nature. Here we show that self-organized clusters of look-a-likes may emerge spontaneously from coevolution of competitors. The explanation is that there are two alternative ways to survive together: being sufficiently different or being sufficiently similar. Using a model based on classical competition theory, we demonstrate a tendency for evolutionary emergence of regularly spaced lumps of similar species along a niche axis. Indeed, such lumpy patterns are commonly observed in size distributions of organisms ranging from algae, zooplankton, and beetles to birds and mammals, and could not be well explained by earlier theory. Our results suggest that these patterns may represent self-constructed niches emerging from competitive interactions. A corollary of our findings is that, whereas in species-poor communities sympatric speciation and invasion of open niches is possible, species-saturated communities may be characterized by convergent evolution and invasion by look-a-likes. | ||||
| Address | Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 8080, 6700 DD, Wageningen, The Netherlands. marten.scheffer@wur.nl | ||||
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| Language | English | Summary Language | Original Title | ||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0027-8424 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:16585519 | Approved |
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| Call Number | refbase @ user @ | Serial | 510 | ||
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| Author | Zhou, W.-X.; Sornette, D.; Hill, R.A.; Dunbar, R.I.M. | ||||
| Title | Discrete hierarchical organization of social group sizes | Type | Journal Article | ||
| Year | 2005 | Publication | Proceedings. Biological sciences / The Royal Society | Abbreviated Journal | Proc Biol Sci |
| Volume | 272 | Issue | 1561 | Pages | 439-444 |
| Keywords | Anthropology, Cultural; *Group Structure; Humans; *Models, Biological; *Social Behavior; *Social Environment | ||||
| Abstract | The 'social brain hypothesis' for the evolution of large brains in primates has led to evidence for the coevolution of neocortical size and social group sizes, suggesting that there is a cognitive constraint on group size that depends, in some way, on the volume of neural material available for processing and synthesizing information on social relationships. More recently, work on both human and non-human primates has suggested that social groups are often hierarchically structured. We combine data on human grouping patterns in a comprehensive and systematic study. Using fractal analysis, we identify, with high statistical confidence, a discrete hierarchy of group sizes with a preferred scaling ratio close to three: rather than a single or a continuous spectrum of group sizes, humans spontaneously form groups of preferred sizes organized in a geometrical series approximating 3-5, 9-15, 30-45, etc. Such discrete scale invariance could be related to that identified in signatures of herding behaviour in financial markets and might reflect a hierarchical processing of social nearness by human brains. | ||||
| Address | State Key Laboratory of Chemical Reaction Engineering, East China University of Science and Technology, Shanghai 200237, China | ||||
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| Language | English | Summary Language | Original Title | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0962-8452 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:15734699 | Approved |
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| Call Number | refbase @ user @ | Serial | 549 | ||
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| Author | Izar, P.; Ferreira, R.G.; Sato, T. | ||||
| Title | Describing the organization of dominance relationships by dominance-directed tree method | Type | Journal Article | ||
| Year | 2006 | Publication | American journal of primatology | Abbreviated Journal | Am. J. Primatol. |
| Volume | 68 | Issue | 2 | Pages | 189-207 |
| Keywords | Animals; Cebus/physiology; *Models, Biological; *Social Dominance | ||||
| Abstract | Methods to describe dominance hierarchies are a key tool in primatology studies. Most current methods are appropriate for analyzing linear and near-linear hierarchies; however, more complex structures are common in primate groups. We propose a method termed “dominance-directed tree.” This method is based on graph theory and set theory to analyze dominance relationships in social groups. The method constructs a transitive matrix by imposing transitivity to the dominance matrix and produces a graphical representation of the dominance relationships, which allows an easy visualization of the hierarchical position of the individuals, or subsets of individuals. The method is also able to detect partial and complete hierarchies, and to describe situations in which hierarchical and nonhierarchical principles operate. To illustrate the method, we apply a dominance tree analysis to artificial data and empirical data from a group of Cebus apella. | ||||
| Address | Department of Experimental Psychology, University of Sao Paulo, Brazil. patrizar@usp.br | ||||
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| Language | English | Summary Language | Original Title | ||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0275-2565 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:16429416 | Approved |
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| Call Number | refbase @ user @ | Serial | 723 | ||
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| Author | Hamilton, W.D. | ||||
| Title | Geometry for the selfish herd | Type | Journal Article | ||
| Year | 1971 | Publication | Journal of theoretical biology | Abbreviated Journal | J. Theor. Biol. |
| Volume | 31 | Issue | 2 | Pages | 295-311 |
| Keywords | Animals; Anura; *Behavior, Animal; Breeding; Communication; Evolution; Fear; Metallurgy; *Models, Biological; Probability; Snakes; *Spatial Behavior | ||||
| Abstract | This paper presents an antithesis to the view that gregarious behaviour is evolved through benefits to the population or species. Following Galton (1871) and Williams (1964) gregarious behaviour is considered as a form of cover-seeking in which each animal tries to reduce its chance of being caught by a predator. It is easy to see how pruning of marginal individuals can maintain centripetal instincts in already gregarious species; some evidence that marginal pruning actually occurs is summarized. Besides this, simply defined models are used to show that even in non-gregarious species selection is likely to favour individuals who stay close to others. Although not universal or unipotent, cover-seeking is a widespread and important element in animal aggregation, as the literature shows. Neglect of the idea has probably followed from a general disbelief that evolution can be dysgenic for a species. Nevertheless, selection theory provides no support for such disbelief in the case of species with outbreeding or unsubdivided populations. The model for two dimensions involves a complex problem in geometrical probability which has relevance also in metallurgy and communication science. Some empirical data on this, gathered from random number plots, is presented as of possible heuristic value. |
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| Language | English | Summary Language | Original Title | ||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0022-5193 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:5104951 | Approved |
no | ||
| Call Number | refbase @ user @ | Serial | 771 | ||
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| Author | Uehara, T.; Yokomizo, H.; Iwasa, Y. | ||||
| Title | Mate-choice copying as Bayesian decision making | Type | Journal Article | ||
| Year | 2005 | Publication | The American naturalist | Abbreviated Journal | Am Nat |
| Volume | 165 | Issue | 3 | Pages | 403-410 |
| Keywords | Animals; *Bayes Theorem; *Choice Behavior; Female; Male; *Models, Biological; *Sexual Behavior, Animal | ||||
| Abstract | Mate-choice copying by females has been reported in fishes (e.g., guppies) and lekking birds. Presumably, females assess males' quality using both information from direct observation of males and information acquired by observing other females' choices. Here, we study mathematically the conditions under which mate-choice copying is advantageous on the basis of Bayesian decision theory. A female may observe the mate choice of another female, called the model female, who has performed an optimal choice based on her own judgment. The conditions required for the focal female to choose the same mate as that chosen by the model female should depend on the male's appearance to her, the reliability of her own judgment of male quality, and the reliability of the model females. When three or more females are involved, the optimal mate choice critically depends on whether multiple model females make decisions independently or they themselves copy the choices of others. If two equally reliable females choose different males, the choice of the second female, made knowing the choice of the first, should have a stronger effect on the choice of the third (focal) female. This “last-choice precedence” should be tested experimentally. | ||||
| Address | Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan. uehara@bio-math.biology.kyushu-u.ac.jp | ||||
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| Language | English | Summary Language | Original Title | ||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 1537-5323 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:15729669 | Approved |
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| Call Number | Serial | 1821 | |||
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| Author | Tobin, T.; Combie, J.D. | ||||
| Title | Performance testing in horses: a review of the role of simple behavioral models in the design of performance experiments | Type | Journal Article | ||
| Year | 1982 | Publication | Journal of Veterinary Pharmacology and Therapeutics | Abbreviated Journal | J Vet Pharmacol Ther |
| Volume | 5 | Issue | 2 | Pages | 105-118 |
| Keywords | Analgesics, Opioid/pharmacology; Animals; Apomorphine/pharmacology; Behavior, Animal/*drug effects; Dose-Response Relationship, Drug; Fentanyl/pharmacology; Horses/*physiology; Methylphenidate/pharmacology; *Models, Biological; Motor Activity/drug effects | ||||
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| Language | English | Summary Language | Original Title | ||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0140-7783 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:6125601 | Approved |
no | ||
| Call Number | refbase @ user @ | Serial | 1957 | ||
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| Author | Dubois, F.; Giraldeau, L.-A. | ||||
| Title | The forager's dilemma: food sharing and food defense as risk-sensitive foraging options | Type | Journal Article | ||
| Year | 2003 | Publication | The American Naturalist | Abbreviated Journal | Am Nat |
| Volume | 162 | Issue | 6 | Pages | 768-779 |
| Keywords | Animals; Competitive Behavior/*physiology; *Environment; Feeding Behavior/*physiology; *Game Theory; *Models, Biological; Population Density; Population Dynamics | ||||
| Abstract | Although many variants of the hawk-dove game predict the frequency at which group foraging animals should compete aggressively, none of them can explain why a large number of group foraging animals share food clumps without any overt aggression. One reason for this shortcoming is that hawk-dove games typically consider only a single contest, while most group foraging situations involve opponents that interact repeatedly over discovered food clumps. The present iterated hawk-dove game predicts that in situations that are analogous to a prisoner's dilemma, animals should share the resources without aggression, provided that the number of simultaneously available food clumps is sufficiently large and the number of competitors is relatively small. However, given that the expected gain of an aggressive animal is more variable than the gain expected by nonaggressive individuals, the predicted effect of the number of food items in a clump-clump richness-depends on whether only the mean or both the mean and variability associated with payoffs are considered. More precisely, the deterministic game predicts that aggression should increase with clump richness, whereas the stochastic risk-sensitive game predicts that the frequency of encounters resulting in aggression should peak at intermediate clump richnesses or decrease with increasing clump richness if animals show sensitivity to the variance or coefficient of variation, respectively. | ||||
| Address | Departement des Sciences Biologiques, Universite du Quebec a Montreal, Case postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada. fdubois@u-bourgogne.fr | ||||
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| Language | English | Summary Language | Original Title | ||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-0147 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:14737714 | Approved |
no | ||
| Call Number | Serial | 2132 | |||
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| Author | Kaplan, A.I.; Borodovskii, M.I. | ||||
| Title | [Alternative animal behavior: a model and its statistical characteristics] | Type | Journal Article | ||
| Year | 1989 | Publication | Nauchnye Doklady Vysshei Shkoly. Biologicheskie Nauki | Abbreviated Journal | Nauchnye Doki Vyss Shkoly Biol Nauki |
| Volume | Issue | 3 | Pages | 29-32 | |
| Keywords | Animals; *Behavior, Animal; Cognition; Male; Mathematics; *Models, Biological; *Models, Statistical; Rats; Reinforcement (Psychology) | ||||
| Abstract | The rats' alternative behaviour in T-maze at simultaneous two-sided food refreshment in 13 trials a day during 6 days has been studied. It has been found that in the first testing days the indexes of alternative behaviour of animals correspond to the characteristics of the random alternation. However, on the 5-6th day of testing in the overwhelming majority of rats the true deviation of alternation index above or below than the theoretical values has been revealed. A question on the existence of two strategies of cognitive behaviour alteration and perseveration in rat population is under discussion. | ||||
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| Language | Russian | Summary Language | Original Title | Al'ternativnoe povedenie zhivotnykh: model' i statisticheskie kharakteristiki | |
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0470-4606 | ISBN | Medium | ||
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| Notes | PMID:2742929 | Approved |
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| Call Number | Equine Behaviour @ team @ | Serial | 2799 | ||
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