Formal Darwinism as a tool for understanding the status of organisms in evolutionary biology

This paper uses the framework of Formal Darwinism (FD) to evaluate organism-centric critiques of the Modern Synthesis (MS). The first section argues that the FD project reconciles two kinds of selective explanations in biology. Thus it is not correct to say that the MS neglects organisms—instead, it explains organisms’ design, as argued in the second section. In the third section I employ a concept of the organism derived from Kant that has two aspects: the parts presupposing the whole, and the productivity of the parts in relation to the whole. The first aspect corresponds to the “design” that FD explains, whereas the second aspect is something about which the MS is largely silent.     

Assessing understanding in biology

This paper discusses several new assessment strategies that encourage meaningful learning and conceptual understanding in the biological sciences. Our purpose is to introduce a handful of evaluation and measurement techniques that help students assimilate well-integrated, strongly cohesive frameworks of interrelated concepts as a way of facilitating ‘real understanding’ of natural phenomena. Among these methods are concept maps, V diagrams, SemNet software, image-based test items, clinical interviews, portfolios, written products, performance measures, and conceptual diagnostic tests. Evidence suggests that these methods are most useful at highlighting ‘alternative conceptions’ and assisting students who wish to ‘learn how to learn’.     

Synthetic biology in multicellular organisms: Opportunities in nematodes

Synthetic biology has mainly focused on introducing new or altered functionality in single cell systems: primarily bacteria, yeast, or mammalian cells. Here, we describe the extension of synthetic biology to nematodes, in particular the well-studied model organism Caenorhabditis elegans, as a convenient platform for developing applications in a multicellular setting. We review transgenesis techniques for nematodes, as well as the application of synthetic biology principles to construct nematode gene switches and genetic devices to control motility. Finally, we discuss potential applications of engineered nematodes.     

Gut feelings: the emerging biology of gut-brain communication

The concept that the gut and the brain are closely connected, and that this interaction plays an important part not only in gastrointestinal function but also in certain feeling states and in intuitive decision making, is deeply rooted in our language. Recent neurobiological insights into this gut-brain crosstalk have revealed a complex, bidirectional communication system that not only ensures the proper maintenance of gastrointestinal homeostasis and digestion but is likely to have multiple effects on affect, motivation and higher cognitive functions, including intuitive decision making. Moreover, disturbances of this system have been implicated in a wide range of disorders, including functional and inflammatory gastrointestinal disorders, obesity and eating disorders.     

Trachoma organisms: technical advances in laboratory diagnosis.

New knowledge of the microbiology and immunology of Chlamydia is reviewed. New serological and isolation methods for diagnosis of Trachoma infection are described. Results of studies of ocular and genital Trachoma infection utilizing these new techniques are presented.     

Classification of organisms and structuralism in biology

Structuralism in biology is the oldest trend oriented to the search for natural "laws of forms" comparable with laws of growth of crystal, was revived at the end of 20th century on the basis of structuralist thought in socio-humanitarian sciences. The development of principal ideas of the linguistic structuralism in some aspects is similar to that of biological systematics, especially concerning the relationships between "system" and "evolution". However, apart from this general similarity, biological structuralism is strongly focused on familiar problems of the origin of diversity in nature. In their striving for the renovation of existing views, biological structuralists oppose the neo-darwinism emphasizing the existence of "law of forms", that are independent on heredity and genetic "determinism". The trend to develop so-called "rational taxonomy" is also characteristic of biological structuralism but this attempt failed being connected neither with Darwin's historicism nor with Plato's typology.     

Metacyclogenesis: a basic process in the biology of Leishmania

Metacyclogenesis is a process whereby Leishmania transforms from poorly infective procyclic promastigotes into highly infective metacyclic promastigotes. In nature, metacyclogenesis occurs in the insect vector. This transformation is accompanied by an increased ability to infect and survive in the vertebrate host, where the parasite is attacked by the host's immune system. Metacyclogenesis has also been shown to occur in axenic cultures of promastigotes. Morphological changes in size and shape, and length of flagellum were first associated with differentiation in the insect gut and in different phases of growth in culture. Later, the expression of molecules such as LPG and the surface protease gp63 were associated with this process. These two molecules were observed to undergo qualitative and quantitative modifications as the promastigotes differentiated from procyclic to metacyclic forms. Using cDNA subtractive hybridization-based methods or differential amplification, previously unknown genes tightly linked to metacyclogenesis have been identified. Gene products exclusively expressed in metacyclic promastigotes included a gene B product and Mat-1--a gene associated with metacyclogenesis. Other proteins, Meta-1, SHERP and HASP, were up-regulated during the metacyclic stage. The function and stage-regulated expression of these molecules and their relationship with infectivity are now under investigation.     

Some advances in coelacanth biology

Participants in the British-French-American Expedition to the Comoro Islands in 1972 were able to observe a living coelacanth and to obtain fresh tissue from two specimens, which were processed in the field for subsequent research. This work, by many people in several countries, still continues, and this lecture gives a condensed account of some of the investigations so far published and in progress. Separate accounts of the French contributions, by J. Anthony, of the chemistry of the body fluids, by R. W. Griffith, and of the respiration, by G. M. Hughes, are being published concurrently, the four papers being complementary to each other. A bibliography on Latimeria is included.     

Recent advances in retromer biology

The endosomal network is an organized array of intracellular, membranous compartments that function as sorting sites for endosomal and biosynthetic cargo. The fate of endocytic cargo is reliant upon interactions with a number of molecularly distinct sorting complexes, which tightly control the relationship between sorting of their respective cargo and the physical process of membrane re-scuplturing required for the formation of transport carries. One such complex, retromer, mediates retrograde transport from endosomes to the trans-Golgi network (TGN). Disregulation of retromer has been implicated in a host of disease states including late-onset Alzheimer's. Rather than give a broad overview of retromer biology, here we aim to outline the recent advances in understanding this complex, focussing on the involvement of both clathrin and the cytoskeleton in retromer function.     

Cell biology of deep-sea multicellular organisms

Establishing tissue cultures derived from deep-sea multicellular organisms has been extremely difficult because of the serious damage they sustain upon decompression and exposure to the high temperature of surface seawater. We developed a novel pressure-stat aquarium system for the study of living deep-sea multicellular organisms under pressure. Using this system, we have succeeded in maintaining a variety of deep-sea multicellular organisms under pressure and atmospheric conditions after gradual, slow decompression. Furthermore, we successfully cultivated and freeze-stocked pectoral fin cells of the deep-sea eel Simenchelys parasiticus collected at a depth of 1,162 m under atmospheric pressure conditions. This review describes novel capture and maintenance devices for deep-sea organisms and cell culture studies of the organisms under atmospheric and pressure conditions.