Traditionally, species have been treated as classes. In fact they may be considered individuals. The logical term “individual” has been confused with a biological synonym for “organism.” If species are individuals, then: 1) their names are proper, 2) there cannot be instances of them, 3) they do not have defining properties, 4) their constituent organisms are parts, not members. “ Species " may be defined as the most extensive units in the natural economy such that reproductive competition occurs among their (...) parts. Species are to evolutionary theory as firms are to economic theory: this analogy resolves many issues, such as the problems of “reality” and the ontological status of nomenclatorial types. (shrink)

Evolutionary theory is undergoing an intense period of discussion and reevaluation. This, contrary to the misleading claims of creationists and other pseudoscientists, is no harbinger of a crisis but rather the opposite: the field is expanding dramatically in terms of both empirical discoveries and new ideas. In this essay I briefly trace the conceptual history of evolutionary theory from Darwinism to neo-Darwinism, and from the Modern Synthesis to what I refer to as the Extended Synthesis, a more inclusive conceptual framework (...) containing among others evo–devo, an expanded theory of heredity, elements of complexity theory, ideas about evolvability, and a reevaluation of levels of selection. I argue that evolutionary biology has never seen a paradigm shift, in the philosophical sense of the term, except when it moved from natural theology to empirical science in the middle of the 19th century. The Extended Synthesis, accordingly, is an expansion of the Modern Synthesis of the 1930s and 1940s, and one that—like its predecessor—will probably take decades to complete. (shrink)

Uniformitarianism is a dual concept. Substantive uniformitarianism (a testable theory of geologic change postulating uniformity of rates or material conditions) is false and stifiqng to hypothesis formation. Methodological uniformitarianism (a procedural principle asserting spatial and temporal invariance of natural laws) belongs to the definition of science and is not unique to genic~~. Methodological uniformitarianism enabled Lyell to exclude the miraculous from geologic explanation; its invocation today is anachronistic since the question of divine intervention is no longer an issue in science. (...) Substantive uniformitarianism, an incorrect theory, should be abandoned. Methodological uniformitarianism, now a superfiuous term, is best confined to the past history of geology. (shrink)

PUNCTUATED cquilibrium has finally obtained an unambiguous and incontrovertiblc majoxity—that is, our theory is now 21 ' years old. We also, with parental pride (and, therefore, potential..

In this paper Wimsatt's analysis of units of selection is taken as defining the units of selection question. A definition of levels of selection is offered and it is shown that the levels of selection question is quite different from the units of selection question. Some of the relations between units and levels are briefly explored. It is argued that the levels of selection question is the question relevant to explanatory concerns, and it is suggested that it is the question (...) relevant to ontological concerns. (shrink)

A model is presented to account for the natural selection of what is termed reciprocally altruistic behavior. The model shows how selection can operate -against the cheater (non-reciprocator) in the system. Three instances of altruistic behavior are discussed, the evolution of which the model can explain: (1) behavior involved in cleaning symbioses; (2) warning cries in birds: and (3) human reciprocal altruism. Regarding human reciprocal altruism, it is shown that the details of the psychological system that regulates this altruism can (...) be explained by the model. Specifically, friendship,d islike, moralistic aggression, gratitude, sympathy, trust, suspicion, trustworthiness, aspects of guilt, and some forms of dishonesty and hypocrisy can be explained as important adaptations to regulate the altruistic system. Each individual human is seen as possessing altruistic and cheating tendencies, the expression of which is sensitive to developmental variables that were selected to set the tendencies at a balance appropriate to the local social and ecological environment. (shrink)

What at bottom is meant by calling the universe many or by calling it one? -/- Pragmatically interpreted, pluralism or the doctrine that it is many means only that the sundry parts of reality may be externally related. Everything you can think of, however vast or inclusive, has on the pluralistic view a genuinely "external" environment of some sort or amount. Things are "with" one another in many ways, but nothing includes everything, or dominates over everything. The word "and" trails (...) along after every sentence. Something always escapes. "Ever not quite" has to be said of the best attempts made anywhere in the universe at attaining all-inclusiveness. The pluralistic world is thus more like a federal republic than like an empire or a kingdom. However much may be collected, however much may report itself as present at any effective centre of consciousness or action, something else is self-governed and absent and unreduced to unity. -/- Monism, on the other hand, insists that when you come down to reality as such, to the reality of realities, everything is present to everything else in one vast instantaneous co-implicated completeness -- nothing can in any sense, functional or substantial, be really absent from anything else, all things interpenetrate and telescope together in the great total conflux. (shrink)

Oaks exemplify problems with the reproductive species concept which motivate a reconsideration of the use and nature of species. Ecology is important in the reconsideration. The species level is usually overemphasized in evolutionary thought; selection acts on phenotypes and any mutualistic units. Standard definitions tend to inhibit free conceptual progress. Multispecies, sets of broadly sympatric species that exchange genes, may occur among animals as well as plants and may conceivably bridge kingdoms. This phenomenon can be adaptively important. There may be (...) taxa without species. The degree of modality of adaptive zones can be investigated empirically. (shrink)

he theory o f natural selection provides a mechanistic, causal account of how living things came to look as if they had been designed for a purpose. So overwhelming is the appearance of purposeful design that, even in this Darwinian era when we know "better," we still find it difficult, indeed boringly pedantic, to refrain from teleological language when discussing adaptation. Birds' wings are obviously "for" flying, spider webs are for catching insects, chlorophyll molecules are for photosynthesis, DNA molecules are (...) for... What are DNA molecules for? The question takes us aback. In my case it touches off an almost audible alarm siren in the mind. If we accept the view of life that I wish to espouse, it is the forbidden question. DNA is not "for" anything. If we wish to speak teleologically, all adaptations are for the preservation of DNA; DNA itself just is. Following Williams, I have advocated this view at length, and I do not want to repeat myself here. Instead I shall try to clear up an important misunderstanding of the view, a misunderstanding that has constituted an unnecessary barrier to its acceptance. (shrink)