Studies of multiple paternity in mammals and other animal species generally report proportion of multiple paternity among litters, mean litter sizes, and mean number of sires per litter. It is shown how these variables can be used to produce an estimate of the probability of reproductive success for a male that has mated with a female. This estimate of male success is more informative about the mating system that alternative measures, like the proportion of litters with multiple paternity or the (...) mean number of sires per litter. The probability of success for a mated male can be measured both theoretically and empirically, and gives an estimate of the intensity of sperm competition and of a male's “confidence of paternity” upon mating. The probability of success for mated males for ten “exemplar” species of mammals is estimated and they are compared for insights into the functioning of their mating systems. (shrink)

This work is the latest contribution to the Clarendon Later Ancient Philosophers series edited by Jonathan Barnes and A. A. Long. As with the earlier volumes (John Dillon's Alcinous, The Handbook of Platonism , R. J. Hankinson's Galen, On the Therapeutic Method Books I and II, Richard Bett's Sextus Empiricus, Against the Ethicists, and D. L. Blank's Sextus Empiricus, Against the Grammarians), D(obbin) provides an introduction, an English translation, and a critical commentary predominantly focused on the philosophical content of the (...) text of an author from the period ranging from the first century BC to the fifth century AD. A bibliography of a dozen earlier editions of E(pictetus), a painstaking bibliography of secondary literature, an index nominum, a generous index locorum, and a brief subject index are also included. Overall this edition maintains the high standards characteristic of the CLAP series. (shrink)

Parentage analyses via microsatellite markers have revealed multiple paternity within the broods of polytocous species of mammals, reptiles, amphibians, fishes and invertebrates. The widespread phenomenon of multiple paternity may have attending relationships with such evolutionary processes as sexual selection and kin selection. However, just how much multiple paternity should a species exhibit? We developed Bayesian null models of how multiple paternity relates to brood sizes. For each of 114 species with published data on brood sizes and numbers of sires, we (...) compared our null model estimates to published frequencies of multiple paternity. The majority of species fell close to our null model, especially among fish and invertebrate species. Some species, however, had low probabilities of multiple paternity, far from the predictions of the null model, likely due to sexual selection and environmental constraints. We suggest a major division among species’ mating systems between those with close to random mating and high levels of multiple paternity, and those with constraints that produce low levels of multiple paternity. (shrink)

In “The Will to Believe,” William James affirms that we have some control over what we believe and asks how this control should be exercised. He rejects the evidentialists’ view that we ought to believe only when intellectual grounds make it quite sure that the belief is true. For him, “options” are choices among contrary beliefs. Some options are “living,” “forced,” and “momentous.” James’ thesis concerns belief-options that have these three features and where proof as to the truth is unavailable. (...) He holds that in such cases we have a right to believe, provided believing has better consequences than not believing would. James is correct that sometimes it is permissible to believe without adequate grounds. His view is misleading, though, when he leaves the impression that this is so only where the option is living, forced, momentous, and not settleable by evidence. The right to believe has broader scope than this. Moreover, James’ right to believe presupposes a view of truth at odds with his later pragmatism. (shrink)

:The most basic question one can ask of a model is ‘What is the effect on variable y2 of variable y1?’ Causation is ‘implementation neutral’ when all interventions on external variables that lead to a given change in y1 have the same effect on y2, so that the effect of y1 on y2 is defined unambiguously. Familiar ideas of causal analysis do not apply when causation is implementation neutral. For example, a cause variable cannot be linked to an effect variable (...) by both a direct path and a distinct indirect path. Discussion of empirical aspects of implementation neutrality leads to further unexpected results, such as that if one variable causes another the coefficient representing that causal link is always identified. (shrink)

In this book a distinguished group of environmental experts argues that in order to solve global environmental problems, we must view them in a broad interdisciplinary perspective that recognizes the relations—the interconnected circle—among ecology, economics, and ethics. Currently the circle is broken, they say, because environmental policy is decided on short-term estimations of material that take little account of the economic or moral burdens that will be borne by future generations if we deplete our resources now. We must, assert the (...) authors, have a better knowledge of the science underlying our environmental problems, we must understand their causes and consequences in relation to our economic and political systems, and we must recognize that an effective response will require a shift in a technologically oriented society’s ethical attitude toward the natural environment. The authors address a wide range of concerns from global atmospheric degradation and spreading toxification of the environment to loss of forests and massive species extinctions. They offer to general readers, students, and professionals practical assessments and remedies for many of these problems. They suggest, for example, mechanisms that provide economic incentives for conservation; engineering and technical adaptations to use resources more effectively and dispose of waste products; better economic accounting procedures for measuring the real environmental costs of our depletion of natural resources; and a remodeled education system that better prepares us to see each individual’s responsibility to the environment. (shrink)