Joined: June 2007
anyone into this sort of thing...
|Olivier Rieppel. 2008. Species as a Process. Acta Biotheoretica Sep 2008. |
Abstract Species are generally considered to be the basic units of evolution, and hence to constitute spatio-temporally bounded entities. In addition, it has been argued that species also instantiate a natural kind. Evolution is fundamentally about change. The question then is how species can remain the same through evolutionary change. Proponents of the species qua individuals thesis individuate species through their unique evolutionary origin. Individuals, or spatio-temporally located particulars in general, can be bodies, objects, events, or processes, or a combination of these. It is here argued that species are best understood as open or closed, causally integrated processual systems that also instantiate an historically conditioned homeostatic property cluster natural kind.
Keywords Species - Systems - Presentism - Eternalism - Endurance - Perdurance - Futuralism
here is a bit
|Eternalism takes time as a fourth dimension that is on par with the three dimensions of space. Space-time forms a four-dimensional continuum, as is required by the space-time ontology of modern physics (Rea 2003). On that account, all the space-time slices of an object, past, present, and future, ‘co-exist’ in four dimensions. A perduring object then forms a space-time worm (Loux 2003, p. 223), as do species on a perdurantist–eternalist account (Hull 1989, p. 187; Brogaard 2004, p. 226). Species cannot be extinct, they can only be ‘far away’. Nor can species evolve in the Darwinian sense of the word, since they have no future that could bring about genuine change.|
any physicists care to comment on this view of time?
|As was emphasized by Rea (2003, p. 274), presentism is in strong accord with intuition, whereas eternalism seeks empirical support from contemporary theories of physics (Sklar 2006). Where the presentist has a problem to identify the duration of the present, the eternalist has the problem of identifying the ‘thickness’ of the temporal parts (space—time slices) of the perduring object. For some philosophers such as Whitehead (1920), time obtains from the passing of nature. But if we cannot keep time from passing, we also cannot hold nature still: “There is no holding nature still and looking at it” (Whitehead 1920, p. 14). A perduring object, or species, thus threatens to disintegrate into a series of theoretically infinitely thin time-slices, i.e., fleeting Whiteheadian ‘occasions’ (Whitehead 1979) that are spatio-temporally located parts of processes whose moment “of becoming is also their moment of perishing” such that they themselves neither change nor move (Sherburne 1966, pp. 210, 222). If the question is how one and the same (numerically identical) species can persist through temporal change, an ontology premised on the notion that nothing exists for any substantial length of time would not solve the problem. Identity conditions for persistence through time would lose their relevance (Haslanger 2003, p. 335). Herein lies a strong motivation for four-dimensionalism that results from an eternalist account of time, as was employed by Whitehead (1979) in his process philosophy—an account that was also adopted by Hennig (1950, 1966; see Rieppel 2007b).|
Some authors take a four-dimensional space-time worm to be “the mereological fusions of instantaneous temporal parts or stages located at different times” (Crisp 2003, p. 216). Such a space-time worm stands in contrast to one whose segments are events or processes, which naturally extend through time. Organisms (Bertalanffy 1932, 1941; Hennig 1950, 1966; Rieppel 2007a) as well as evolving species take part in processes, indeed can be seen to be processes themselves (see further discussion below, and in Rieppel 2007b); Hennig (1950, 1966) realized with respect to his concept of the semaphoront that instantaneous temporal parts or stages are not a suitable ontology to capture developing organisms (Rieppel 2003, 2007b), and the same is true for evolving species. Such a radical, indeed Whiteheadian interpretation of the perdurantist–eternalist account contrasts with another possible interpretation of four-dimensionalism, which does not take time as another dimension on par with space, but which takes a persisting object to be identical with its history (Gallois 2005, p. 8). On that account, the species is a sequence of events that is identical with its history, i.e., a process that extends through space and time. History has not only a past and a present, but also a future, distinctions that are denied on the perdurantist–eternalist account. A species that is a four-dimensional space-time worm (Hull 1989, p. 187; Brogaard 2004, p. 226) has no past, nor any future: it just is (Hull 1989, p. 187). Accordingly, and for Hull (1989 , p. 187), “the species name Cygnus olor” refers “both to a spatio-temporally extended lineage and to a time-slice of that lineage.” This is why Løvtrup (1979, p. 390) contrasts Hull’s (1976) views with his own, where species (‘terminal taxa’ in Løvtrup’s (1977, 1979) axiomatic system) remain active players in the arena of evolution, making history.
Presentism yields a non-dimensional species concept (Mayr 1963, 1982) that fails to capture the species as an evolutionary process. Eternalism likewise cannot capture the species as an evolutionary process, as there is no past, nor any potential for future change and innovation. As will be illustrated by a brief excursion into the history of biology, a ‘third way’, a new metaphysics of change is required to capture species that are “evolution in the making” (Løvtrup 1977, p. 50).
i do not know many young biologists who are concerned with these issues. yet they seem grave enough to warrant consideration. these concepts form the foundation for discussing "speciation" and macroevolution, yet there are deep schisms between schools of thought that cannot be addressed by simply "following the evidence".
You're obviously illiterate as hell. Peach, bro.-FtK
Finding something hard to believe based on the evidence, is science.-JoeG
the odds of getting some loathsome taint are low-- Gordon E Mullings Manjack Heights Montserrat
I work on molecular systems with pathway charts and such.-Giggles