Ageing and the goal of evolution.

There is a certain metaphor that has enjoyed tremendous longevity in the evolution of ageing literature. According to this metaphor, nature has a certain goal or purpose, the perpetuation of the species, or, alternatively, the reproductive success of the individual. In relation to this goal, the individual organism has a function, job, or task, namely, to breed and, in some species, to raise its brood to maturity. On this picture, those who cannot, or can no longer, reproduce are somehow invisible to, or even dispensable to, the evolutionary process. Here, I argue that the metaphor should be discarded, not on the grounds that it is a metaphor, but on the grounds that this particular metaphor distorts our understanding of the evolution of ageing. One reason the metaphor is problematic is that it frames senescence and death as nature's verdict on the value of older individuals. Instead, we should explore a different metaphor: the lengthy post-reproductive period in humans and some other animals is not an accident of culture, but designed by nature for the purpose of supporting and guiding younger generations. On this alternate picture, different stages of life have their own evolutionary rationales, their distinctive design features, their special mandates.

The origin of the coding metaphor in neuroscience.

To assess Brette's proposal to expunge "coding" from the neuroscientist's lexicon, we must consider its origins. The coding metaphor is due largely to British nerve physiologist Edgar Adrian. I suggest two ways that the coding metaphor fueled his research. I conclude that the debate today should not be about the "truth" of the metaphor but about its continuing utility.

Two types of psychological hedonism.

I develop a distinction between two types of psychological hedonism. Inferential hedonism (or "I-hedonism") holds that each person only has ultimate desires regarding his or her own hedonic states (pleasure and pain). Reinforcement hedonism (or "R-hedonism") holds that each person's ultimate desires, whatever their contents are, are differentially reinforced in that person's cognitive system only by virtue of their association with hedonic states. I'll argue that accepting R-hedonism and rejecting I-hedonism provides a conciliatory position on the traditional altruism debate, and that it coheres well with the neuroscientist Anthony Dickinson's theory about the evolutionary function of hedonic states, the "hedonic interface theory." Finally, I'll defend R-hedonism from potential objections.

The birth of information in the brain: Edgar Adrian and the vacuum tube.

ARGUMENT: As historian Henning Schmidgen notes, the scientific study of the nervous system would have been "unthinkable" without the industrialization of communication in the 1830s. Historians have investigated extensively the way nerve physiologists have borrowed concepts and tools from the field of communications, particularly regarding the nineteenth-century work of figures like Helmholtz and in the American Cold War Era. The following focuses specifically on the interwar research of the Cambridge physiologist Edgar Douglas Adrian, and on the technology that led to his Nobel-Prize-winning research, the thermionic vacuum tube. Many countries used the vacuum tube during the war for the purpose of amplifying and intercepting coded messages. These events provided a context for Adrian's evolving understanding of the nerve fiber in the 1920s. In particular, they provide the background for Adrian's transition around 1926 to describing the nerve impulse in terms of "information," "messages," "signals," or even "codes," and for translating the basic principles of the nerve, such as the all-or-none principle and adaptation, into such an "informational" context. The following also places Adrian's research in the broader context of the changing relationship between science and technology, and between physics and physiology, in the first few decades of the twentieth century.

What is the value of historical fidelity in restoration?

The following considers the role of historical fidelity in habitat reconstruction efforts. To what extent should habitat reconstruction be guided by the goal of recreating some past state of a damaged ecosystem? I consider Sarkar's "replacement argument," which holds that, in most habitat reconstruction efforts, there is little justification for appealing to historical fidelity. I argue that Sarkar does not provide adequate grounds for deprecating historical fidelity relative to other natural values such as biodiversity or wild nature.

Alexander Forbes, Walter Cannon, and science-based literature.

The Harvard physiologists Alexander Forbes (1882-1965) and Walter Bradford Cannon (1871-1945) had an enormous impact on the physiology and neuroscience of the twentieth century. In addition to their voluminous scientific output, they also used literature to reflect on the nature of science itself and its social significance. Forbes wrote a novel, The Radio Gunner, a literary memoir, Quest for a Northern Air Route, and several short stories. Cannon, in addition to several books of popular science, wrote a literary memoir in the last year of his life, The Way of an Investigator. The following will provide a brief overview of the life and work of Forbes and Cannon. It will then discuss the way that Forbes used literature to express his views about the changing role of communications technology in the military, and his evolving view of the nervous system itself as a kind of information-processing device. It will go on to discuss the way that Cannon used literature to articulate the horrors he witnessed on the battlefield, as well as to contribute to the philosophy of science, and in particular, to the logic of scientific discovery. Finally, it will consider the historical and philosophical value of deeper investigation of the literary productions of scientists.

Place prioritization for biodiversity content.

The prioritization of places on the basis of biodiversity content is part of any systematic biodiversity conservation planning process. The place prioritization procedure implemented in the ResNet software package is described. This procedure is primarily based on the principles of rarity and complementarity. Application of the procedure is demonstrated with two analyses, one data set consisting of the distributions of termite genera in Namibia, and the other consisting of the distributions of bird species in the Islas Malvinas/Falkland Islands. The attributes that data sets should have for the effective and reliable application of such procedures are discussed. The procedure used here is compared to some others that are also currently in use.

Birds as surrogates for biodiversity: an analysis of a data set from southern Québec.

Surrogacy analysis consists of determining a set of biotic or environmental parameters which can be rapidly assessed in the field and reliably used to prioritize places for biodiversity conservation. Whether adequate surrogate sets exist remains an open and relatively unexplored question though its solution is central to the aims of conservation biology. This paper analyses the surrogacy problem by prioritizing places using surrogate lists and comparing these results with those obtained by using more comprehensive species lists. More specifically, it explores (i) the possibility of using bird distributions, which are often easily available, as surrogates for species at risk (endangered and threatened species), which are presumed to be an important component of biodiversity; and (ii) the methodological question of how spatial scale influences surrogate success. The data set analysed, from southern Québec, is one of the most complete biotic data sets available at the regional scale. Contrary to some previous analyses, the results obtained suggest that the surrogacy problem is potentially solvable.