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Hampton, R. R., Sherry, D. F., Shettleworth, S. J., Khurgel, M., & Ivy, G. (1995). Hippocampal volume and food-storing behavior are related in parids. Brain Behav Evol, 45(1), 54–61.
Abstract: The size of the hippocampus has been previously shown to reflect species differences and sex differences in reliance on spatial memory to locate ecologically important resources, such as food and mates. Black-capped chickadees (Parus atricapillus) cached more food than did either Mexican chickadees (P. sclateri) or bridled titmice (P. wollweberi) in two tests of food storing, one conducted in an aviary and another in smaller home cages. Black-capped chickadees were also found to have a larger hippocampus, relative to the size of the telencephalon, than the other two species. Differences in the frequency of food storing behavior among the three species have probably produced differences in the use of hippocampus-dependent memory and spatial information processing to recover stored food, resulting in graded selection for size of the hippocampus.
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Connor, R. J., Kawaoka, Y., Webster, R. G., & Paulson, J. C. (1994). Receptor specificity in human, avian, and equine H2 and H3 influenza virus isolates. Virology, 205(1), 17–23.
Abstract: The receptor specificity of 56 H2 and H3 influenza virus isolates from various animal species has been determined to test the relevance of receptor specificity to the ecology of influenza virus. The results show that the receptor specificity of both H2 and H3 isolates evaluated for sialic acid linkage specificity and inhibition of hemagglutination by horse serum correlates with the species of origin, as postulated earlier for H3 strains based on a limited survey of five human, three avian, and one equine strain. Elucidation of the amino acid sequence of several human H2 receptor variants and analysis of known sequences of H2 and H3 isolates revealed that receptor specificity varies in association with an amino acid change at residues 228 in addition to the change at residue 226 previously documented to affect receptor specificity of H3 but not H1 isolates. Residues 226 and 228 are leucine and serine in human isolates, which preferentially bind sialic acid alpha 2,6-galactose beta 1,4-N-acetyl glucosamine (SA alpha 2,6Gal), and glutamine and glycine in avian and equine isolates, which exhibit specificity for sialic acid alpha-2,3-galactose beta-1,3-N-acetyl galactosamine (SA alpha 2,3Gal). The results demonstrate that the correlation of receptor specificity and species of origin is maintained across both H2 and H3 influenza virus serotypes and provide compelling evidence that influenza virus hosts exert selective pressure to maintain the receptor specificity characteristics of strains isolated from that species.
Keywords: Amino Acid Sequence; Amino Acids/genetics; Animals; Carbohydrate Sequence; Chick Embryo; Hemagglutinin Glycoproteins, Influenza Virus; Hemagglutinins, Viral/genetics; Influenza A virus/*metabolism; Molecular Sequence Data; Receptors, Virus/*metabolism; Species Specificity; Viral Envelope Proteins/genetics
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Shettleworth, S. J. (1993). Varieties of learning and memory in animals. J Exp Psychol Anim Behav Process, 19(1), 5–14.
Abstract: It is often assumed that there is more than one kind of learning--or more than one memory system--each of which is specialized for a different function. Yet, the criteria by which the varieties of learning and memory should be distinguished are seldom clear. Learning and memory phenomena can differ from one another across species or situations (and thus be specialized) in a number of different ways. What is needed is a consistent theoretical approach to the whole range of learning phenomena, and one is explored here. Parallels and contrasts in the study of sensory systems illustrate one way to integrate the study of general mechanisms with an appreciation of species-specific adaptations.
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Hart, D., & Whitlow, J. W. J. (1995). The experience of self in the bottlenose dolphin. Conscious Cogn, 4(2), 244–247.
Abstract: Marten and Psarakos have presented some evidence which suggests that objective self-awareness and possibly representations of self may characterize the dolphins' experience of self. Their research demonstrates the possibility of similarities in the sense of self between primate species and dolphins, although whether dolphins have subjective self-awareness, personal memories, and theories of self--all important facets of the sense of self in humans--was not examined. Clearly, even this limited evidence was difficult to achieve; the difficulties in adapting methods and coding behavior are quite apparent in their report. Future progress, however, may depend upon clarification of what are the necessary components for a sense of self and an explication of how these might be reflected in dolphin behavior. We are mindful of the authors' point (pp. 219 and 220) that the dolphin lives more in an acoustic than a visual environment. Thus, while tasks relying upon vision may reveal the presence or absence of the sense of self in primates, it might well be the case that in dolphins self-related experiences might be better revealed in auditory tasks. But then, what is the nature of human self-awareness in terms of audition? While both conceptual and methodological hurdles remain, Marten and Psarakos have demonstrated that important questions can be asked about the minds and phenomenal worlds of nonanthropoid species.
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Loveland, K. A. (1995). Self-recognition in the bottlenose dolphin: ecological considerations. Conscious Cogn, 4(2), 254–257. |
Barton, R. A. (1996). Neocortex size and behavioural ecology in primates. Proc. R. Soc. Lond. B, 263(1367), 173–177.
Abstract: The neocortex is widely held to have been the focus of mammalian brain evolution, but what selection pressures explain the observed diversity in its size and structure? Among primates, comparative studies suggest that neocortical evolution is related to the cognitive demands of sociality, and here I confirm that neocortex size and social group size are positively correlated once phylogenetic associations and overall brain size are taken into account. This association holds within haplorhine but not strepsirhine primates. In addition, the neocortex is larger in diurnal than in nocturnal primates, and among diurnal haplorhines its size is positively correlated with the degree of frugivory. These ecological correlates reflect the diverse sensory-cognitive functions of the neocortex.
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Reboreda, J. C., Clayton, N. S., & Kacelnik, A. (1996). Species and sex differences in hippocampus size in parasitic and non-parasitic cowbirds. Neuroreport, 7(2), 505–508.
Abstract: To test the hypothesis that selection for spatial abilities which require birds to locate and to return accurately to host nests has produced an enlarged hippocampus in brood parasites, three species of cowbird were compared. In shiny cowbirds, females search for host nests without the assistance of the male; in screaming cowbirds, males and females inspect hosts' nests together; in bay-winged cowbirds, neither sex searches because this species is not a brood parasite. As predicted, the two parasitic species had a relatively larger hippocampus than the non-parasitic species. There were no sex differences in relative hippocampus size in screaming or bay-winged cowbirds, but female shiny cowbirds had a larger hippocampus than the male.
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Hampton, R. R., & Shettleworth, S. J. (1996). Hippocampal lesions impair memory for location but not color in passerine birds. Behav Neurosci, 110(4), 831–835.
Abstract: The effects of hippocampal complex lesions on memory for location and color were assessed in black-capped chickadees (Parus atricapillus) and dark-eyed juncos (Junco hyemalis) in operant tests of matching to sample. Before surgery, most birds were more accurate on tests of memory for location than on tests of memory for color. Damage to the hippocampal complex caused a decline in memory for location, whereas memory for color was not affected in the same birds. This dissociation indicates that the avian hippocampus plays an important role in spatial cognition and suggests that this brain structure may play no role in working memory generally.
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Hampton, R. R., & Shettleworth, S. J. (1996). Hippocampus and memory in a food-storing and in a nonstoring bird species. Behav Neurosci, 110(5), 946–964.
Abstract: Food-storing birds maintain in memory a large and constantly changing catalog of the locations of stored food. The hippocampus of food-storing black-capped chickadees (Parus atricapillus) is proportionally larger than that of nonstoring dark-eyed juncos (Junco hyemalis). Chickadees perform better than do juncos in an operant test of spatial non-matching-to-sample (SNMTS), and chickadees are more resistant to interference in this paradigm. Hippocampal lesions attenuate performance in SNMTS and increase interference. In tests of continuous spatial alternation (CSA), juncos perform better than chickadees. CSA performance also declines following hippocampal lesions. By itself, sensitivity of a given task to hippocampal damage does not predict the direction of memory differences between storing and nonstoring species.
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Parker, S. T. (1997). A general model for the adaptive function of self-knowledge in animals and humans. Conscious Cogn, 6(1), 75–86.
Abstract: This article offers a general definition of self-knowledge that embraces all forms and levels of self-knowledge in animals and humans. It is hypothesized that various levels of self-knowledge constitute an ordinal scale such that each species in a lineage displays the forms of self-knowledge found in related species as well as new forms it and its sister species may have evolved. Likewise, it is hypothesized that these various forms of levels of self-knowledge develop in the sequence in which they evolved. Finally, a general hypothesis for the functional significance of self-knowledge is proposed along with subhypotheses regarding the adaptive significance of various levels of self-knowledge in mammals including human and nonhuman primates. The general hypothesis is that self-knowledge serves as a standard for assessing the qualities of conspecifics compared to those of the self. Such assessment is crucial to deciding among alternative reproductive and subsistence strategies. The qualities that are assessed, which vary across taxa, range from the size and strength of the self to its mathematical or musical abilities. This so-called assessment model of self-knowledge is based on evolutionary biological models for social selection and the role of assessment in animal communication.
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