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Amdam, G. V., Csondes, A., Fondrk, M. K., & Page, R. E. J. (2006). Complex social behaviour derived from maternal reproductive traits. Nature, 439(7072), 76–78.
Abstract: A fundamental goal of sociobiology is to explain how complex social behaviour evolves, especially in social insects, the exemplars of social living. Although still the subject of much controversy, recent theoretical explanations have focused on the evolutionary origins of worker behaviour (assistance from daughters that remain in the nest and help their mother to reproduce) through expression of maternal care behaviour towards siblings. A key prediction of this evolutionary model is that traits involved in maternal care have been co-opted through heterochronous expression of maternal genes to result in sib-care, the hallmark of highly evolved social life in insects. A coupling of maternal behaviour to reproductive status evolved in solitary insects, and was a ready substrate for the evolution of worker-containing societies. Here we show that division of foraging labour among worker honey bees (Apis mellifera) is linked to the reproductive status of facultatively sterile females. We thereby identify the evolutionary origin of a widely expressed social-insect behavioural syndrome, and provide a direct demonstration of how variation in maternal reproductive traits gives rise to complex social behaviour in non-reproductive helpers.
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Parr, L. A., Hopkins, W. D., & de Waal, F. B. (1997). Haptic discrimination in capuchin monkeys (Cebus apella): evidence of manual specialization. Neuropsychologia, 35(2), 143–152.
Abstract: Two experiments investigated the effects of haptic and visual discrimination on hand preference in 22 brown capuchin monkeys (Cebus apella). The percentage of left-handed subjects in Experiment 1 were 63.6%, 45.5%, and 18.2% for haptic, bipedal, and quadrupedal reaching, respectively. In Experiment 2, the haptic demands of the task were manipulated by using additional food types and another tactile medium. Left-hand preferences were further strengthened when reaching into water compared to pineshavings in Experiment 1. Reaching with no tactile interference resulted in equal numbers of lateralized and nonlateralized subjects. These results show that when reaching demands the use of haptic cues, as opposed to visual ones, monkeys shift towards greater left hand use. This is consistent with what is known about right hemisphere superiority for haptic discrimination in humans.
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Milgram, N. W., Head, E., Muggenburg, B., Holowachuk, D., Murphey, H., Estrada, J., et al. (2002). Landmark discrimination learning in the dog: effects of age, an antioxidant fortified food, and cognitive strategy. Neurosci Biobehav Rev, 26(6), 679–695.
Abstract: The landmark discrimination learning test can be used to assess the ability to utilize allocentric spatial information to locate targets. The present experiments examined the role of various factors on performance of a landmark discrimination learning task in beagle dogs. Experiments 1 and 2 looked at the effects of age and food composition. Experiments 3 and 4 were aimed at characterizing the cognitive strategies used in performance on this task and in long-term retention. Cognitively equivalent groups of old and young dogs were placed into either a test group maintained on food enriched with a broad-spectrum of antioxidants and mitochondrial cofactors, or a control group maintained on a complete and balanced food formulated for adult dogs. Following a wash-in period, the dogs were tested on a series of problems, in which reward was obtained when the animal responded selectively to the object closest to a thin wooden block, which served as a landmark. In Experiment 1, dogs were first trained to respond to a landmark placed directly on top of coaster, landmark 0 (L0). In the next phase of testing, the landmark was moved at successively greater distances (1, 4 or 10 cm) away from the reward object. Learning varied as a function of age group, food group, and task. The young dogs learned all of the tasks more quickly than the old dogs. The aged dogs on the enriched food learned L0 significantly more rapidly than aged dogs on control food. A higher proportion of dogs on the enriched food learned the task, when the distance was increased to 1cm. Experiment 2 showed that accuracy decreased with increased distance between the reward object and landmark, and this effect was greater in old animals. Experiment 3 showed stability of performance, despite using a novel landmark, and new locations, indicating that dogs learned the landmark concept. Experiment 4 found age impaired long-term retention of the landmark task. These results indicate that allocentric spatial learning is impaired in an age-dependent manner in dogs, and that age also affects performance when the distance between the landmark and target is increased. In addition, these results both support a role of oxidative damage in the development of age-associated cognitive dysfunction and indicate that short-term administration of a food enriched with supplemental antioxidants and mitochondrial cofactors can partially reverse the deleterious effects of aging on cognition.
Keywords: Age Factors; Aging/*physiology; Analysis of Variance; Animals; Antioxidants/*pharmacology; Blood Chemical Analysis/methods; Cognition/*physiology; *Diet; Discrimination Learning/*drug effects/*physiology; Distance Perception/drug effects/physiology; Dogs/physiology; Female; Male; Psychomotor Performance/physiology; Retention (Psychology)/drug effects/physiology; Spatial Behavior/*drug effects/*physiology; Task Performance and Analysis; Time Factors; Vitamin E/blood
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Valone, T. J. (1989). Group foraging, public information, and patch estimation. Oikos, 56(3), 357–363.
Abstract: Public information is information about the quality of a patch that can be obtained by observing the foraging success of other individuals in that patch. I examine the influence of the use of public information on patch departure and foraging efficiency of group members. When groups depart a patch with the first individual to leave, the use of public information can prevent the underutilization of resource patches.
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Lee, R. D. (2003). Rethinking the evolutionary theory of aging: transfers, not births, shape senescence in social species. Proc Natl Acad Sci U S A, 100(16), 9637–9642.
Abstract: The classic evolutionary theory of aging explains why mortality rises with age: as individuals grow older, less lifetime fertility remains, so continued survival contributes less to reproductive fitness. However, successful reproduction often involves intergenerational transfers as well as fertility. In the formal theory offered here, age-specific selective pressure on mortality depends on a weighted average of remaining fertility (the classic effect) and remaining intergenerational transfers to be made to others. For species at the optimal quantity-investment tradeoff for offspring, only the transfer effect shapes mortality, explaining postreproductive survival and why juvenile mortality declines with age. It also explains the evolution of lower fertility, longer life, and increased investments in offspring.
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Corr, J. A. (2004). Nuns and monkeys: investigating the behavior of our oldest old. Sci Aging Knowledge Environ, 2004(41), pe38.
Abstract: The use of nonhuman primates, particularly rhesus macaques (Macaca mulatta), as the best model for human physiological and cognitive aging is broadly accepted. Studies employing nonhuman primates to investigate behavioral changes that may occur with increasing age, however, are not common mostly because of the unavailability of appropriate subjects. Recent longitudinal human studies suggest that individual personality might play a large role in aging “successfully” and in the retention of high levels of cognition into old age. As a result of the demographic trend of increasing numbers of aged monkeys and apes in captivity, an opportunity exists to further investigate behavioral aging using the monkey model.
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McHugh, C. P. (1989). Ecology of a semi-isolated population of adult Anopheles freeborni: abundance, trophic status, parity, survivorship, gonotrophic cycle length, and host selection. Am J Trop Med Hyg, 41(2), 169–176.
Abstract: A population of adult Anopheles freeborni near Sheridan, CA was sampled daily during 13 August-7 September 1984. Data on abundance, trophic status, and gonotrophic age were recorded. Abundance and gonotrophic age data were analyzed to estimate daily survivorship and gonotrophic cycle length. Daily survivorship for unfed mosquitoes was estimated to be 0.72 with a gonotrophic cycle of 6 days duration. Daily survivorship for bloodfed mosquitoes was estimated to be 0.74 with a gonotrophic cycle of 4 days. The 2 day difference in gonotrophic cycles between unfed and bloodfed mosquitoes was the result of the period required for maturation and mating of teneral females. In 1986, an incage release of field-collected females estimated survivorship at 0.75 per day. Precipitin tests of 1,338 blood-engorged mosquito abdomens indicated that bovids, horses, rabbits, and canids comprised 92% of bloodmeals; no bloodmeals of human origin were detected.
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Landsberg, G., & Araujo, J. A. (2005). Behavior problems in geriatric pets. Vet Clin North Am Small Anim Pract, 35(3), 675–698.
Abstract: Aging pets often suffer a decline in cognitive function (eg, memory,learning, perception, awareness) likely associated with age-dependent brain alterations. Clinically, cognitive dysfunction may result in various behavioral signs, including disorientation; forgetting of previously learned behaviors, such as house training; alterations in the manner in which the pet interacts with people or other pets;onset of new fears and anxiety; decreased recognition of people, places, or pets; and other signs of deteriorating memory and learning ability. Many medical problems, including other forms of brain pathologic conditions, can contribute to these signs. The practitioner must first determine the cause of the behavioral signs and then determine an appropriate course of treatment, bearing in mind the constraints of the aging process. A diagnosis of cognitive dysfunction syndrome is made once other medical and behavioral causes are ruled out.
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Connor, R. C., Mann, J., Tyack, P. L., & Whitehead, H. (1998). Social evolution in toothed whales. Trends. Ecol. Evol, 13(6), 228–232.
Abstract: Two contrasting results emerge from comparisons of the social systems of several odontocetes with terrestrial mammals. Researchers have identified remarkable convergence in prominent features of the social systems of odontocetes such as the sperm whale and bottlenose dolphin with a few well-known terrestrial mammals such as the elephant and chimpanzee. In contrast, studies on killer whales and Baird's beaked whale reveal novel social solutions to aquatic living. The combination of convergent and novel features in odontocete social systems promise a more general understanding of the ecological determinants of social systems in both terrestrial and aquatic habitats, as well as the relationship between relative brain size and social evolution.
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