Altruism
Mostrando 37-48 de 59 artigos, teses e dissertações.
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37. Kin recognition and the evolution of altruism.
In 1964, Hamilton formalized the idea of kin selection to explain the evolution of altruistic behaviours. Since then, numerous examples from a diverse array of taxa have shown that seemingly altruistic actions towards close relatives are a common phenomenon. Although many species use kin recognition to direct altruistic behaviours preferentially towards rela
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38. Competition among cooperators: Altruism and reciprocity
Levine argues that neither self-interest nor altruism explains experimental results in bargaining and public goods games. Subjects' preferences appear also to be sensitive to their opponents' perceived altruism. Sethi and Somanathan provide a general account of reciprocal preferences that survive under evolutionary pressure. Although a wide variety of recipr
National Academy of Sciences.
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39. Altruism, Society, Health Care
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40. Altruism, blood donation and public policy: a reply to Keown.
This is a continuation of and a development of a debate between John Keown and me. The issue discussed is whether, in Britain, an unpaid system of blood donation promotes and is justified by its promotion of altruism. Doubt is cast on the notions that public policies can, and, if they can, that they should, be aimed at the promotion and expression of altruis
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41. Group selection, altruism, reinforcement, and throwing in human evolution.
Evolution of altruism by group selection involves sacrifice of some individuals, not to the "group as a whole," but to other individuals in the group. Deme-group selection may establish strictly altruistic genes in a population, but only under limited conditions, and perhaps never among vertebrates, among which apparently altruistic behaviors may always pote
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42. Sex-ratio conflicts, kin selection, and the evolution of altruism
Kin-selection theory has thrived in the explanation of a wide variety of biological phenomena, chiefly the evolution of biological altruism as that found in sterile castes of eusocial insects. Much of the way in which it has been tested is based on the existence of conflicts over sex-ratio production within eusocial colonies. However, despite neatly showing
The National Academy of Sciences.
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43. Gene-culture coevolution of complex social behavior: human altruism and mate choice.
The hypothesis is examined that genes bias the development of complex social behavior in one direction over alternatives. Studies of altruism and political attitudes in twins estimate that approximately 50% of the variance is associated with direct genetic inheritance, virtually 0% with the twin's common family environment, and the remainder with each twin's
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44. A quantitative genetic model of reciprocal altruism: a condition for kin or group selection to prevail.
A condition is derived for reciprocal altruism to evolve by kin or group selection. It is assumed that many additively acting genes of small effect and the environment determine the probability that an individual is a reciprocal altruist, as opposed to being unconditionally selfish. The particular form of reciprocal altruism considered is TIT FOR TAT, a stra
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45. Maintainence of parasitaemia – is it to die for?
One of the major differences between protozoan differentiation and metazoan differentiation is that protozoan cells normally retain potency during differentiation, which need not, therefore, be considered altruistic. Altruism does, however, arise at the level of the organism and consequently, protozoons have the potential to evolve altruistic traits. This is
BioMed Central.
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46. Population genetic theory of kin selection: Multiple alleles at one locus
Exact population genetic models of one-locus sib-to-sib kin selection with an arbitrary number of alleles are studied. First, a natural additive scaling is established for the genotypic value associated with probabilities of performance of altruism. Two classes of polymorphic equilibria are possible, one corresponding to the usual one-locus viability equilib
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47. Effect of phenotypic variation on kin selection
An expression for the equilibrium of the mean phenotypic value of a quantitative character is derived for a model in which the fitness of an individual depends on its own phenotype and the mean phenotypic value of a group of related individuals. When selection is weak the equilibrium mean is well predicted by Hamilton's k > 1/r rule (k is the ratio of mean f
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48. 'Pals'. A medical student public service program.
We designed a public service and educational program to aid children and families coping with chronic illness and to augment medical student education. Medical students developed relationships with chronically ill children and families based on the Big Brother-Big Sister program model. In addition, students attended bimonthly seminars on childhood chronic il