Mechanical explanation of nature and its limits in Kant’s Critique of judgment

In this paper I discuss two questions. What does Kant understand by mechanical explanation in the Critique of judgment? And why does he think that mechanical explanation is the only type of the explanation of nature available to us? According to the interpretation proposed, mechanical explanations in the Critique of judgment refer to a particular species of empirical causal laws. Mechanical laws aim to explain nature by reference to the causal interaction between the forces of the parts of matter and the way in which they form into complex material wholes. Just like any other empirical causal law, however, mechanical laws can never be known with full certainty. The conception according to which we can explain all of nature by means of mechanical laws, it turns out, is based on what Kant calls ‘regulative’ or ‘reflective’ considerations about nature. Nothing in Kant’s Critique of judgment suggests that these considerations can ever be justified by reference to how the natural world really is. I suggest that what, upon first consideration, appears to be a thoroughly mechanistic conception of nature in Kant is much more limited than one might have expected.     

Naturalising purpose: from comparative anatomy to the 'adventure of reason'

Kant's analysis of the concept of natural purpose in the Critique of judgment captured several features of organisms that he argued warranted making them the objects of a special field of study, in need of a special regulative teleological principle. By showing that organisms have to be conceived as self-organizing wholes, epigenetically built according to the idea of a whole that we must presuppose, Kant accounted for three features of organisms conflated in the biological sciences of the period: adaptation, functionality and conservation of forms. Kant's unitary concept of natural purpose was subsequently split in two directions: first by Cuvier's comparative anatomy, that would draw on the idea of adaptative functions as a regulative principle for understanding in reconstituting and classifying organisms; and then by Goethe's and Geoffroy's morphology, a science of the general transformations of living forms. However, such general transformations in nature, objects of an alleged 'archaeology of nature', were thought impossible by Kant in section paragraph 80 of the Critique of judgment. Goethe made this 'adventure of reason' possible by changing the sense of 'explanation': scientific explanation was shifted from the investigation of the mechanical processes of generation of individual organisms to the unveiling of some ideal transformations of types instantiated by those organisms.     

Kant’s concept of natural purpose and the reflecting power of judgement

This paper examines how in the ‘Critique of teleological judgment’ Kant characterized the concept of natural purpose in relation to and in distinction from the concepts of nature and the concept of purpose he had developed in his other critical writings. Kant maintained that neither the principles of mechanical science nor the pure concepts of the understanding through which we determine experience in general provide adequate conceptualizations of the unique capacities of organisms. He also held that although the concept of natural purpose was derived through reflection upon an analogy to human purposive activity in artistic production and moral action, it articulates a unique notion of intrinsic purposiveness. Kant restricted his critical reflections on organisms to phenomena that can be given to us in experience, criticizing speculations on their first origins or final purpose. But I argue that he held that the concept of natural purpose is a product of the reflecting power of judgment, rather than an empirical concept, and represents only the relation of things to our power of judgment. Yet it is necessary for the identification of organisms as organized and self-organizing, and as subject to unique norms and causal relations between parts and whole.     

Kant on biological teleology: Towards a two-level interpretation

According to Kant's Critique of the power of judgment, teleological considerations are unavoidable for conceptualizing organisms. Does this mean that teleology is more than merely heuristic? Kant stresses the regulative status of teleological attributions, but sometimes he seems to treat teleology as a constitutive condition for biology. To clarify this issue, the concept of natural purpose and its role for biology are examined. I suggest that the concept serves an identificatory function: it singles out objects as natural purposes, whereby the special science of biology is constituted. This relative constitutivity of teleology is explicated by means of a distinction of levels: on the object level of biological science, teleology is taken as constitutive, though it is merely regulative on the philosophical meta level. This distinction also concerns the place of Aristotelian teleology in Kant: on the object level, the Aristotelian view is accepted, whereas on the meta level, an agnostic stance is taken concerning teleology.     

Cellular “bauplans”: Evolving unicellular forms by means of Julia sets and Pickover biomorphs

The universe of cellular forms has received scarce attention by mainstream neo-Darwinian views. The possibility that a fundamental trait of biological order may consist upon, or be guided by, developmental processes not completely amenable to natural selection was more akin to previous epochs of biological thought, i.e. the “bauplan” discussion. Thirty years ago, however, Lynn and Tucker studied the biological mechanisms responsible for defining organelles position inside cells. The fact that differentiated structures performing a specific function within the eukaryotic cell (i.e. mitochondrion, vacuole, or chloroplast) were occupying specific positions in the protoplasm was the observational and experimental support of the ‘morphogenetic field’ notion at the cellular level. In the present paper we study the morphogenetic field evolution yielding from an initial population of undifferentiated cells to diversified unicellular organisms as well as specialized eukaryotic cell types. The cells are represented as Julia sets and Pickover biomorphs, simulating the effect of Darwinian natural selection with a simple genetic algorithm. The morphogenetic field “defines” the locations where cells are differentiated or sub-cellular components (or organelles) become organized. It may be realized by different possibilities, one of them by diffusing chemicals along the Turing model. We found that Pickover cells show a higher diversity of size and form than those populations evolved as Julia sets. Another novelty is the way that cellular organelles and cell nucleus fill in the cell, always in dependence on the previous cell definition as Julia set or Pickover biomorph. Our findings support the existence of specific attractors representing the functional and stable form of a differentiated cell—genuine cellular bauplans. The configuration of the morphogenetic field is “attracted” towards one or another attractor depending on the environmental influences as modeled by a particular fitness function. The model promotes the classical discussions of D’Arcy Thompson and the more recent views of Waddington, Goodwin and others that consider organisms as dynamical systems that evolve through a ‘master plan’ of transformations, amenable to natural selection. Intriguingly, the model also connects with current developments on mechanobiology, highlighting the informational–developmental role that cytoskeletons may play.     

Candidatus Monilibacter spp., common bulking filaments in activated sludge, are members of Cluster III Defluviicoccus

Two alphaproteobacterial Neisser negative ‘Nostocoida limicola’ morphotypes differing slightly in their trichome diameter and filament regularity were dominant populations in the Bendigo, Victoria, Australia activated sludge community removing phosphorus (P). Neither responded to the FISH probes available for any of the other alphaproteobacterial ‘N. limicola’ morphotypes. Instead both fluoresced with the DF988 FISH probe designed originally to target alphaproteobacterial cluster II Defluviicoccus tetrad forming organisms. A 16S rRNA based clone library from this biomass revealed that the alphaproteobacterial clones grouped closely with Candidatus ‘Monilibacter batavus’ and Defluviicoccus clones in a cluster separate from the existing cluster I and II Defluviicoccus. When a FISH probe was designed against these, it only hybridized to the thinner and less abundant ‘N. limicola’ morphotype. Micromanipulation–RT-PCR was used to selectively recover the main ‘N. limicola’ morphotype and a FISH probe designed against the 16S rRNA clones generated from it showed only this filament fluoresced. From FISH based surveys, both ‘N. limicola’ variants occurred frequently in phosphorus removal activated sludge systems in Australia treating domestic waste. The data suggest that they represent two new strains of Candidatus ‘Monilibacter’, which on this evidence are filamentous members of the genus Defluviicoccus, a potential competitor for the polyphosphate accumulating organisms in these communities.     

Cytogenetic stability of <Emphasis Type="Italic">Centaurea ragusina</Emphasis> long-term culture

Centaurea ragusina L. (Asteraceae) is an endemic Croatian plant species, which developed xeromorphic characteristics as a consequence of its natural environment – vertical limestone cliffs above the Adriatic sea. Cytogenetic status of C. ragusina long-term culture (94th subculture) and C. ragusina seedlings was analysed and compared after 4 weeks of growth. Cytogenetic stability was investigated in root meristem cells of C. ragusina cultured plants originated from Pen đa (cliffs near Dubrovnik) and seedlings originated from three different localities in south Adriatic (Penđa, Pasjača – cliffs near Dubrovnik and island of Komiža) using mitotic index and mitotic and chromosomal abnormalities as parameters. Mitotic indices of cultured plants and ‘Penđa’ seedlings were similar and showed significant increase compared to mitotic indices of ‘Komiža’ and ‘Pasjača’ seedlings. Although the highest number of mitotic abnormalities was recorded in root meristem cells of cultured plants, it was only a bit higher than in root tips of ‘Pasjača’ and ‘Penđa’ seedlings, while that of ‘Komiža’ was two times lower compared to cultured plants. Pattern of analysed mitotic abnormalities was very similar in root tips of cultured plants and ‘Pasjača’ and ‘Penđa’ seedlings, with exception of ‘Komiža’ seedlings. Presented results suggest that long-term cultivation of C. ragusina has almost no effect on culture ageing considering similar distribution of scored mitotic abnormalities as in ‘Penđa’ and ‘Pasjača’ seedlings.     

Molecular Systematics of Middle American Cichlid Fishes and the Evolution of Trophic-Types in ‘Cichlasoma(Amphilophus)’ and ‘C.(Thorichthys)’

The majority of Middle American cichlids are placed in the informal assemblage ‘Cichlasoma.’ The group is divided into eight sections which appear to be based primarily on trophic morphology. Although several members of ‘Cichlasoma’ have been used in ecomorphological, behavioral, and biogeographic studies, no phylogenetic hypotheses for the group exist. In an attempt to develop a better understanding of the phylogenetic relationships of ‘cichlasomine’ cichlids, we examined the evolution of the trophic specialization, substratum-sifting, in two sections, ‘Cichlasoma(Thorichthys)’ and ‘C.(Amphilophus),’ to determine whether the trait reflects common ancestry. We sequenced the complete mitochondrial cytochromebgene for 19 cichlids representing six sections of ‘Cichlasoma,’ and representatives of other Neotropical Cichlidae. Additional cichlid, and noncichlid outgroup sequences were included for a total of 22 taxa. The molecular phylogeny supports the recognition of the section ‘C.(Thoricthys)’ as a natural group, and we place those cichlids in the genusThorichthys.The phylogeny also depicts ‘C.(Amphilophus)’ as paraphyletic, with substratum-sifters and generalized predators forming separate nonsister clades. We recommend that the substratum-sifting clade of the section ‘C.(Amphilophus)’ be placed in the resurrected genusAstatheros.The generalized predator clade of ‘C.(Amphilophus)’ contains only two species, ‘C. (A.) citrinellum’ and ‘C. (A.) labiatum,’ which we place in the genusAmphilophus.The phylogenetic hypotheses generated indicate that the substratum-sifting generaThorichthysandAmphilophusdo not share a common ancestor. Reconstruction of the evolution of substratum-sifting is equivocal, requiring either the independent evolution of the trait on two separate occasions or its presence in a more inclusive clade and subsequent loss in nonsubstratum sifting species.     

Eugenics, politics and the state: social democracy and the Swiss ‘gardening state’

This article explores the connections between eugenics, politics and the state, taking the Swiss case as a particular focus. It is argued that Switzerland provides a historical example of what Bauman [Bauman, Z. (1989). Modernity and the Holocaust. Cambridge: Polity Press.] describes as ‘gardening states’: states that are concerned with eliminating the ‘bad weeds’ from the national garden and thereby constructing sharply exclusionary national identities. The Swiss experiments with eugenics (1920s–1960s) can be seen as an example of an ongoing struggle against ‘difference’. Against this backdrop I will examine, first, the ways in which state regulation of reproductive sexuality, and other eugenic measures, became central mechanisms for dealing with cultural and other ‘differences’ in the Swiss nation. Second, I will analyse the gendered nature of such mechanisms, as well as the preoccupation with racial ‘difference’ exemplified by eugenic policies towards ‘Gypsies’. To conclude, I will examine the impact of political institutions and political ideology, in particular, social democracy, on these eugenic gardening efforts.     

The elevated anthocyanin level in the shaded peel of ‘Anjou’ pear enhances its tolerance to high temperature under high light

Pigments, chlorophyll fluorescence, dark respiration, and the antioxidant system in the shaded peel of green ‘Anjou’ pear (Pyrus communis L.) and its bud mutation, red ‘Anjou’, were compared in response to high peel temperature, high light alone or in combination to determine the protective role of anthocyanins under high temperature with or without light. Under high temperature treatment alone, no difference in the maximum quantum yield of PSII (F_V/F_M) was detected between red ‘Anjou’ and green ‘Anjou’; the superoxide dismutase activity and the glutathione pool were up-regulated in green ‘Anjou’ peel but remained unchanged in red ‘Anjou’ peel. Under high temperature coupled with high light, the F_V/F_M of green ‘Anjou’ peel was decreased to a lower value than that of red ‘Anjou’, and significant interaction was detected between temperature and light for both cultivars. Furthermore, the difference in F_V/F_M between red ‘Anjou’ and green ‘Anjou’ under high temperature coupled with high light was significantly larger than that under high light alone, indicating that this larger difference was caused by the interaction between high temperature and high light as no significant difference was detected in F_V/F_M between the two cultivars under high temperature treatment alone at any sampling point. It is concluded that the elevated anthocyanin level in the shaded peel of red ‘Anjou’ does not alter its thermotolerance in the dark, but makes it more tolerant of high temperature under high light.     

α2-macroglobulin ‘fast’ forms inhibit superoxide production by activated macrophages

Mouse peritoneal macrophages activated by bacillus Calmette-Guerin (BCG) were incubated with human α₂-macroglobulin converted to its ‘fast’ form with either trypsin or methylamine before being stimulated with phorbol myrystate acetate. Both α₂-macroglobulin-trypsin and α₂-macroglobulin-methylamine inhibited macrophage production of superoxide anion (O₂⁻) while native α₂-macroglobulin had little effect except at high concentration. The α₂-macroglobulin ‘fast’ forms, which bind with a K_d of about 8 nM, inhibited 50% generation of O₂⁻(ID₅₀) at a concentration of 7 nM while α₂-macroglobulin inhibited O₂⁻ production with an ID₅₀ of 141 nM. The ‘fast’ forms of α₂-macroglobulin may play a role in the feedback regulation of inflammatory reactions.     

Morphological Stasis of Two Species Belonging to the L-morphotype in the <Emphasis Type="Italic">Brachionus plicatilis</Emphasis> Species Complex

Detection and characterization of sibling species complexes in zooplankton are critical to understanding their ecological responses and patterns of evolution. The taxon Brachionus plicatilis is a complex of at least 14 species with three major, deeply diverged clades, which are morphologically distinct. We studied morphometric differences between two species – B. plicatilis sensu stricto and B. ‘Manjavacas’– which belong to the L-(large) morphotype and often co-occur in ponds or lakes. B. plicatilis s.s. was on average 6% longer than B. ‘Manjavacas’. They differed significantly in the measurements related to lorica spines. A significant discriminant function relating spine measurements was found, however, individuals from each species showed extensive overlap. Our morphometric data provide additional evidence for the species status of B. plicatilis s.s. and B. ‘Manjavacas’. Since these are ancient species, our results support that a morphological stasis occurs in these taxa. We identified COI restriction sites for PvuII and KpnI which are diagnostic for B. ‘Manjavacas’ and B. plicatilis s.s., respectively. We conclude that morphometry is not useful in classifying the two species. At present, this can only be done reliably using molecular methods.     

Thermotropic ‘two-stage’ liquid crystalline crystalline lipid phase separation in microsomal membranes

The effect of temperature on native microsomal membrane vesicles isolated from Tetrahymena is investigated by wide angle X-ray diffraction. A 4.2 Å reflection, typical for lipids in the crystalline state, can be recorded in the temperature range between 0°C and 35°C. Quantitative evaluation of this reflection reveals a broad thermotropic ‘two-stage’ liquid crystallinecrystalline lipid phase separation with a ‘breakpoint’ at approx. 18°C. This ‘breakpoint’ coincides with the emergence of lipid-protein segregations in endomembranes of intact Tetrahymena cells as previously visualized by freeze-etch electron microscopy.     

Oxidative stress,antioxidant activity and Fe(III)-chelate reductase activity of five <Emphasis Type="Italic">Prunus</Emphasis> rootstocks explants in response to Fe deficiency

The aim of this work was to investigate whether Fe reduction and antioxidant mechanisms were expressed differently in five Prunus rootstocks (‘Peach seedling,’ ‘Barrier,’ ‘Cadaman,’ ‘Saint Julien 655/2’ and ‘GF-677’). These rootstocks differ in their tolerance to Fe deficiency when grown in the absence of Fe (−Fe) or in presence of bicarbonate (supplied as 5 or 10 mM NaHCO₃). Fe deficiency conditions, especially bicarbonate, were shown to decrease Fe and total chlorophyll (CHL) concentration. In the (−Fe)-treated roots of all rootstocks and in the 5 mM NaHCO₃-treated ones of the tolerant ‘GF-677’ the Fe(III)-chelate reductase (FCR) activity was stimulated. On the contrary, apart from the ‘GF-677,’ FCR activity was greatly inhibited by the 10 mM NaHCO₃. From the results obtained with decapitated rootstocks, it is not entirely clear whether or not the presence of shoot apex was a prerequisite to induce FCR function in all rootstocks tested. In the leaves of rootstocks exposed to the (−Fe) treatment, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities were enhanced whereas the levels of the non-enzymatic antioxidants (FRAP values) were increased in the Fe-deprived leaves, irrespective of the rootstock. Except for ‘Peach seedling,’ foliar SOD activity was stimulated by the presence of NaHCO₃. Furthermore, POD activity was increased in the ‘Saint Julien 655/2’ and ‘GF-677,’ but was depressed in the ‘Barrier’ rootstocks exposed to 10 mM NaHCO₃. As a result of 10 mM NaHCO₃, the expression of a Cu/Zn-SOD and a POD isoform was diminished in the leaves of ‘Peach seedling’ and ‘Barrier,’ respectively. By contrast, an additional isoform of both POD and Mn–SOD were expressed in the leaves of ‘GF-677’ exposed to 10 mM NaHCO₃ suggesting that the tolerance of rootstocks to Fe deficiency is associated with induction of an antioxidant defense mechanism. Although CAT activity was increased in the 5 mM NaHCO₃-treated leaves of ‘GF-677,’ specifically the 10 mM NaHCO₃ treatment resulted in a decrease of CAT activity and an accumulation of H₂O₂, indicating that bicarbonate-induced Fe deficiency may cause more severe oxidative stress in the rootstocks, than the absence of Fe. A general link between Fe deficiency-induced oxidative stress and Fe reduction-sensing mechanism is also discussed.     

Engineering role models: do non-human species have the answers?

A shift from traditional engineering approaches to ecologically-based techniques will require changing societal values regarding ‘how and what’ is defined as engineering and design. Non-human species offer many ecological engineering examples that are often beneficial to ecosystem function and other biota. For example, organisms known as ‘ecosystem engineers’ build, modify, and destroy habitat in their quest for food and survival. Similarly, ‘keystone species’ have greater impacts on community or ecosystem function than would be predicted from their abundance. The capacity of these types of organisms to affect ecosystems is great. They exert controlling influences over ecosystems and communities by altering resource allocation, creating habitats and modifying relative competitive advantages.Species’ effects in ecosystems, although context-dependent, can be evaluated as ‘beneficial’ or ‘detrimental’. The evaluation depends on whether effects on other species or ecosystem function are more or less desirable from a given perspective. Organisms with beneficial impacts facilitate the presence of other species, employ efficient nutrient cycling, and are sometimes characterized by specific mutualisms. In contrast, many cases of detrimental engineering are found from introduced (i.e., exotic) species and are characterized by a loss of species richness, a lack of nutrient retention and the degradation of ecosystem integrity. Species’ impacts on ecosystems and community traits have been quantified in ecological studies and can be used similarly to understand, design and model human engineering structures and impacts on the landscape. Emulation of species with beneficial impacts on ecosystems can provide powerful guidance to the goals of ecological engineering. Using role model organisms that have desirable effects on species diversity and ecosystem function will be important in developing alternatives to traditional engineering practices.     

The ‘philosophical grasp of the appearances’ and experimental microscopy: Johannes Müller’s microscopical research, 1824–1832

Romantic Naturphilosophie has been at the centre of almost every account of early nineteenth-century sciences, be it as an obstacle or as an aid for scientific advancement. The following paper suggests a change of perspective. I seek to read Naturphilosophie as one manifestation among others of a more general concern with the question of how experience enables the subject to acquire knowledge about objects. To illustrate such an approach, I focus on Johannes Müller’s early work. Here one finds two contrasting images of microscopical observation, its set-up, and the observer: the embryological study of 1830 demands a ‘philosophical grasp’ of the appearances. In contrast, the investigations of blood of 1832 are presented as a series of controlled experiments. I argue that an interpretation of this contrast in terms of an appropriation and casting aside of Naturphilosophie is not altogether convincing. Instead, both images of microscopy are manifestations of a more general problem, namely, the problem of exactly how subject and object came together in experience. I show how this concern not only shaped the methodological sensibilities particular to Müller’s embryology and the investigation of bodily liquids but also provided the epistemological principles and the target for his sense-physiological experiments. It bound Müller’s work together with Naturphilosophie and linked Naturphilosophie with other contemporaneous projects in philosophy. All of these enterprises sought to contribute to ongoing debates about how experience allowed the subject to acquire knowledge about the world.     

The ‘Orsten’—More than a Cambrian Konservat-Lagerstätte yielding exceptional preservation

In several areas of southern Sweden, limestone nodules, locally called Orsten occur within bituminous alum shales. These shales and nodules were deposited under dysoxic conditions at the bottom of what was most likely a shallow sea during the late Middle to Upper Cambrian (ca. 500 million years ago). Subsequently, the name ‘Orsten’ has been referred to particular, mainly arthropod, fossils from such nodules, and, in a wider sense, to the specific type of preservation of minute fossil through secondarily phosphatization. This preservation is exceptional in yielding uncompacted and diagenetically undeformed three-dimensional fossils. ‘Orsten’-type preservation resulted from incrustation of a thin external layer and also by impregnation by calcium phosphate and, therefore, mineralization of the surface of the former animals during early diagenesis. Primarily, this type of preservation seems to have affected only cuticle-bearing metazoans such as cycloneuralian nemathelminths and arthropods. ‘Orsten’ preservation in this sense seems to be limited by size, in having yielded no partial or complete animals larger than 2 mm. On the other end of the scale, even larvae 100 μm long are preserved, often more complete than larger specimens, and details such as setules and pores smaller than 1 μm can be observed. Fossils preserved in such a manner are almost exclusively hollow carcasses, but can be filled secondarily; less common are completely phosphatized compact specimens. The high quality of preservation makes the Swedish ‘Orsten’ a typical Konservat-Lagerstätte. Yet, its special type of preservation is more widespread in time and geographical distribution than assumed initially, and the origin of the phosphate is not necessarily restricted just to one source. Subsequent to the first discoveries of limb fragments of Cambrian arthropods in 1975, animals in this special preservational type have been discovered in several continents and across a broad stratigraphic range including even Proterozoic strata. The latter have yielded early cleavage and metazoan embryonic stages, expanding knowledge on the preservational capacities of the ‘Orsten’. Here, we report the recent status of our research on the ‘Orsten’ and give perspectives for future exploration on a worldwide scale, particularly in light of a recently formed international research group named Center of Orsten Research and Exploration (C.O.R.E.).     

Syntheses of daidzein-7-yl β- -glucopyranosiduronic acid and daidzein-4′,7-yl di-β- -glucopyranosiduronic acid

Syntheses of the title compounds — commonly known as ‘daidzein 7-glucuronide’ and ‘daidzein 4′,7-diglucuronide’ — are described. Selective 7-deacetylation of 4′,7-di-O-acetyldaidzein is employed.