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Specialized networks of movement detectors in the antero-inferior field of the eyes of the fruitfly, Drosophila melanogaster, and the housefly, Musca domestica, respond to upward (or downward) drift of the retinal images by excitation (or inhibition) of the lift-generating force of flight. The influence of the direction of pattern movement upon the altitude control response has been investigated under conditions of fixed flight in still air. Matched model analysis of the available response curves suggests the predominance of unidirectional movement detectors in these networks. Homologous wingbeat-inhibiting detectors in the specified fields of the eyes of the two species respond preferentially to pattern movement from antero-superior to postero-inferior. The arrangement of wingbeat-exciting detectors seems to follow different schemes: These detectors respond preferentially to movement from inferior to superior in Drosophila, and to movement from antero-inferior to postero-superior in Musca. The wingbeat-exciting network in Musca is restricted to a comparatively small antero-equatorial area of the specified fields of the eyes. The combination of the two types of detectors in this area establishes a powerful lift control system which is particularly sensitive to minute deviations from a given level of flight.

To give an exact definition of what we mean when we speak of a fixed motor pattern or a fixed action pattern is difficult because one should not include any working hypotheses in the definition of any biological function or structure that has not already been thoroughly analyzed. Still, it is possible to confess that we believe that the hard core of what we call fixed motor patterns consists in centrally coordinated sequences of endogenously generated impulses, and that this coordination has evolved phylogenetically and is very resistant to any individual modification. A fixed motor pattern’s most important distinction from motor patterns that are not fixed and, simultaneously, the cogent argument for its being genetically programmed, consists in its taxonomic distribution. Fixed motor patterns show, from species to species and from genus to genus, similarities and dissimilarities that concur strictly with those of morphological characters. The discovery of these facts of similarity and dissimilarity is due to the work done by C. H. Whitman and O. Heinroth. They discovered that the concept of homology could be applied to motor patterns in certain “ritualized” movements of courtship in pigeons (Columbidae) and in waterfowl (Anatidae). It is typical for discoveries constituting major breakthroughs that they are made with objects in which the newly found laws of nature are represented in the simplest possible ways. The classic example of this, as already mentioned, is Gregor Mendel’s hitting upon monohybrids, that is, hybrids between races of plants which differ in only one gene. The courtship movements in question also obey the simplest possible laws. They obey the so-called all-or-nothing law of nervous discharge; in other words, their identity is not veiled by the great variability of the forms in which other motor patterns appear in correlation with the varying intensity of their specific excitation. As will be discussed in the following section, even a low excitation can elicit barely noticeable “intention movements,” and with rising excitation, a gradual scale of transitions leads from this “intention” to the fully intensified motor pattern achieving its teleonomic function. In some particular motor patterns which function as signals, this intensity-correlated variability has been abolished in the interest of unambiguity: when they are performed at all, it is always with the same “typical intensity,” as Desmond Morris (1957), who discovered the phenomenon, has described it.

From a linguistic perspective, the Bellman-Goldberg thesis of a necessary relationship between the abilities of organisms to move and communicate is very interesting. Since several concepts and terms are represented in both the thesis and contemporary linguistic literature, these items are discussed in further detail. Questions of the implicit assumptions of the homology of the motor and linguistic systems are also raised here. Finally, there are requests for further clarification on issues of evolution in this test of the strength of the thesis.

In a stimulating essay called ‘On Biological Transformation’1 published in 1945, Woodger attempted to make precise the concept of morphological correspondence which, as he showed, is basic to the concept of homology. He indicated how the concept of morphological correspondence might need modifying if it were to cover the same ground as the concept of homology covers in contemporary biological thought. If one considers the ways in which the concept of homology is applied it turns out that it covers a number of related but different ideas. We talk of a wing of a bird being homologous with a leg of a mammal. We talk of the fore and hind limbs of a vertebrate being serially homologous. We find parts being designated as homologous because they develop from embryonic parts which are homologous, and that the adult homology is based on this. We find two parts are homologous because they have common ancestors. We even find chromosomes are said to be homologous as well as genes, and recently the concept of homologous sera has been put forward.

Successive flares within the same centre of activity sometimes produce radio events that are remarkably similar. The occurrence of such homologous radio events is commonly restricted to periods of less than 48 hours.

(1870). VIII.—On the use of the term “Homology”. Annals and Magazine of Natural History: Vol. 6, No. 32, pp. 113-121.

Precision genomic alterations largely rely on homology directed repair (HDR), but targeting without homology using the non-homologous end-joining (NHEJ) pathway has gained attention as a promising alternative. Previous studies demonstrated precise insertions formed by the ligation of donor DNA into a targeted genomic double-strand break in both dividing and non-dividing cells. Here, we demonstrate the use of NHEJ repair to replace genomic segments with donor sequences; we name this method ‘Replace’ editing ( R ational e nd-joining p rotocol de l ivering a targeted sequen c e e xchange). Using CRISPR/Cas9, we create two genomic breaks and ligate a donor sequence in-between. This exchange of a genomic for a donor sequence uses neither microhomology nor homology arms. We target four loci in cell lines and show successful exchange of exons in 16–54% of human cells. Using linear amplification methods and deep sequencing, we quantify the diversity of outcomes following Replace editing and profile the ligated interfaces. The ability to replace exons or other genomic sequences in cells not efficiently modified by HDR holds promise for both basic research and medicine.

This research examines heterogeneity in Americans' musical tastes by separating breadth and level of taste, taking into account the structural constraints such as cohort, period, social class, gender and racial composition, which have shaped Americans' musical preferences over the past 20 years. We identify four types of respondents who share similar taste patterns that correspond to different degrees of omnivorousness: omnivores, limited, temperates and moderates. We argue that taste patterns deviate from the usual elitist basis in that omnivores are depicted as both highbrow individuals with lowbrow taste and non-highbrow individuals with lowbrow taste. We also find that structural constraints have little impact on breadth of tastes among omnivores and a relatively high impact on breadth of tastes among limited, temperates and moderates. Heterology is emphasized (rather than the Bourdieuvian homology) in an examination of the equivalence between the social structure and the cultural sphere. Heterology recognizes that breadth and level of taste are two independent dimensions of cultural consumption.

We have added a command (SCAN) to PROLANG which allows the user to search for exactly matching subsequences in the PROLANG Protein Sequences Database (PSDB)

Matti Saraste, (Figure 1)(Figure 1) Program Coordinator for Structural and Computational Biology at the European Molecular Biology Laboratory (EMBL), died on May 21, 2001, in Heidelberg, Germany, at the age of 52.Figure 1Matti SarasteView Large Image | View Hi-Res Image | Download PowerPoint SlideMatti Saraste was a pioneer of the combinatorial use of different structural biology methods, such as electron microscopy, X-ray crystallography, NMR spectroscopy, and computational techniques. Much of what is known today about the structural organization of large cytoskeletal proteins can be credited to Matti's research activities. Matti was esteemed for his pivotal contributions to the experimental and structural biology of transmembrane proteins and expertise in the field of bioenergetics. He was instrumental in promoting the integration of the structurally oriented research of signal transduction with the emerging opportunities from genetics, cell biology, and, more recently, proteomics and genomics.Prominent researchers at the EMBL, who have known and collaborated with Matti for many years, have expressed great shock and sorrow at his death. Matti was the driving force behind a better understanding of the mechanisms of vectorial tramsmembrane catalysis and protein-protein interactions in signaling pathways. They also remember him not only as an idealistic scientist who dreamed of a “better society,” but one who took substantial efforts to actualize and incorporate his personal ideals, at least within his own working environment. An advocate of philosophy and anthropology, Matti appreciated and was enriched by the diverse cultural backgrounds of his fellows and colleagues.Matti was a fellow for about one year at Moscow State State University, Moscow, Russia, between 1975 and 1976. He obtained his Ph.D. degree in biochemistry from the University of Helsinki, in Helsinki, Finland, in 1978. In the early 1980s, he spent two years as an EMBO-funded postdoctoral fellow in the laboratory of John E. Walker at the MRC Laboratory of Molecular Biology, in Cambridge, England, where he became centrally involved in setting up experiments on ATP synthases. He frequently described this time as a turning point in his career, during which he discovered the unique opportunities afforded by molecular structural biology. Part of his work provided the basis for the epochal X-ray structure solution of the F1 ATP synthase complex, which led to the Nobel prize being awarded to John Walker.Matti returned to Helsinki, where he became an independent researcher, and in 1989 was appointed Associate Professor of Biochemistry at the University of Helsinki. During these years, he developed double-tracked research interests. One scientific area was on respiratory systems, in particular, the integral membrane protein cytochrome oxidase; the second area was on large cytoskeletal proteins, where he focused on the heterotetrameric protein spectrin. Both systems have been of challenging complexity, not easily amenable to structural biology investigations.With the desire to make most efficient use of the state-of-the-art structural biology facilities available at that time and to experience the unique ambience of an international laboratory, he accepted the offer of independent group leader in the Structural Biology Program at the central laboratory of EMBL in 1990. With an initially small team of extremely motivated European graduate students and postdocs, he resumed his long-term projects: cytochrome oxidase and spectrin. During the subsequent years, he provided a series of pivotal contributions on various domains of these protein giants, often using cut/paste methods for tailoring these entities with the then-available molecular biology techniques. Thanks to the presence of some signaling domains like the Src homology 3 (SH3) domain and the pleckstrin homology (PH) domain in spectrin, he quickly became a scientific addict of signal transduction and rapidly developed a unique ability to put these domains into a wide context of biological processes.Based on his scientific achievements and his leading efforts for integration of the state-of-the-art molecular biology methods, he was appointed Coordinator of the Structural and Computation Biology Program at EMBL in 1996. Since then, he reshaped this program from a primarily methods-oriented one into a unit of mostly young, highly motivated and gifted group leaders with ambitious scientific goals in structural biology, integrated into the heterogeneous environment of the EMBL. Matti has also served as Editor of FEBS Letters since 1987, and more recently was appointed Managing Editor of the same journal. During his later days, he spent substantial effort in improving its peer review process, which led to a significant increase in its scientific impact.As much as Matti loved the international environment at the EMBL, he never lost his strong roots for Finland. Many previous graduate students and postdocs will never forget the unique ambience of social events in his home — where the specific Finnish ingredients, like fires made from juniper wood, smoked fish, and red-colored granberry spirits, served as obligatory additives. Matti liked nature, and being with him in natural habitats in the Alsace or the Black Forest was always a wonderful experience for his fellows. Being a humanitarian, Matti was also a stout supporter of the EMBL's new program “Science and Society.”Matti began his career as an antibourgeoisie-oriented student, reflecting the political climate 20 to 30 years ago; it was no surprise that he initially chose Moscow instead of some of the more prestigious universities in the United States to commence his international career. More recently, the EMBL afforded him a scientific environment that reflected some of his personal, life-long dreams. Scientists of the spirit of Matti are badly needed, especially during times when structural biology is experiencing another golden era, due to epochal determinations of giant protein complexes, while at the same time facing fundamental challenges by structural genomics approaches and a rapidly increasing commercialization of the available techniques. Matti Saraste will be deeply missed both by the scientific community and by his friends who loved him.

As the myths themselves are based on secondary codes (the primary codes being those that provide the substance of language), the present work is put forward as a tentative draft of a tertiary code, which is intended to ensure the reciprocal translatability of several myths. This is why it would not be wrong to consider this book itself as a myth: it is, as it were, the myth of mythology. (L6vi-Strauss 1964:12)

Eighteen extracellular secondary products were identified from members of the Por- pidiaceae. Eight compounds were new to the family, including one, methyl 2'-0-methylmicro- phyllinate, new to science. These secondary products occur in eight sets in particular relative concentrations. Because of their discernibility and reproducibility, each set is meaningfully inter- preted as a taxonomic character state. Each set, or character state, may represent a single recurring chemical pathway, and similarities in the pathways offer a preliminary basis for proposing evolu- tionary homology, suggesting how the individual states might be grouped into characters. Non- homologues, proposed on the basis of dissimilarity, are corroborated by co-occurrence. Most discussion of the concept of evolution- ary homology has been based on morphological examples. Little attention has been given to the interpretation of biochemical characters other than DNA and proteins. The present study ap- plies theory already developed for morpholog- ical characters to infer taxonomic characters and character states from a biochemical data set from lichens.

My interest in this article is in structural equivalences between works in different arts. In other words, I am not interested in comparing specific works in terms of shared images or mutual references either to external "reality" or to one another, as in the work of Panofsky (1939), Praz (1970), Hagstrum (1958), or, most recently, Mitchell (1986). I will instead look into the way different works enact the same period structures in materials and techniques specific to their arts. I will concentrate on postmodernism. Various arts employ various structures. Yet, as Wendy Steiner (1982: 68) reminds us, "an interartistic parallel... is not dictated by the preexistent structures of the arts involved; instead, it is an exploration of how these structures can be aligned." I propose to arrive at such an alignment by examining how postmodern painting and fiction interact with their audiences. Central to my study is Erving Goffman's (1974) frame analysis. Through artistic comparison the present article will contribute to a description of our "contemporary aesthetics" (Steiner 1982: 18). Structural interart comparisons are often theoretically weak. The most common move is to posit some kind of ad hoc parallel, similarity, or homology between the structures of different kinds of works of art, without reference to any general category or categories serving as tertium comparationis. It is my contention that Goffman's idea of "frame" or "frameworks of understanding" may provide us with such a general category. In Frame Analysis Goffman sets out to furnish a general explanation

The authors make the transposition of a semiotic theory of poem, consisting of the traditional semiotic levels, to the theory of the plastic text, in such a way that the absolute homology between all the processes of artistic communication like the plastic ones and the literary ones in proved, distinguishing the level of literarity as conventionalized pragmatic option and the level of poeticality as value based on the effects of the imaginary activity and communication. The authors examine examples of the Spanish modern painting.

Science is communicated through statements about things, sets of things, and processes. The scientific method includes testing statements or hypotheses. An examination of the procedures used in science and the assumptions on which the procedures are based is necessary in order to verify the veracity of the statement made. Commenting on errors is necessary to prevent future workers in the field from adopting a technique or interpretation that lacks support (Blackwelder, 1967). Inferring evolutionary relationships of organisms are categorized into three school of thought: evolutionary taxonomy (e.g., Simpson, 1953,1961; Mayr, 1963,1969), numerical taxonomy (e.g., Sneath and Sokal, 1973) and phylogenetic systematics (e.g., Hennig, 1966; Farris, 1979, 1982, 1983; Wiley, 1981). Only one of these, phylogenetic systematics, provides a means for examining results by reassessing data under adherence to the principles of homology and parsimony (Hennig, 1966). Phylogenetic systematics requires that characters comprising the data sets be understood by the investigator. Ideally, differences in the ontogeny of characters among taxa are known (de Queiroz, 1985) but generally this is not possible and may be unknowable (Kluge, 1985). Characters for which ontogenetic information is not available can be placed within the data sets. This enables the investigator to observe the distribution of the character states in question within the topology of the resultant cladogram and can lead to additional hypotheses concerning the evolution of the characters. Two methods are used to produce cladograms. The hand-generated method is a useful technique for small, clear-cut data sets in which homoplasies are few or absent. As the size of the data set or the possible number of homoplasies increases or both, calculating all possible hypotheses (i.e., trees) and determining which hypothesis best explains the data becomes increasingly difficult (Felsenstein, 1978; Nelson and Platnick, 1981). The second method utilizes high speed computers (Felsenstein, 1982). This requires some procedural step-by-step direction, an algorithm. Although a particular series of steps within the algorithm may reflect a particular philosophy (e.g., in PAUP using the optimizing options ACCTRAN vs. DELTRAN), the computer follows the rules of procedure contained in the algorithm and is not subject to a priori modification at any step during the analysis. Only the investigator can make mistakes in coding or by not including all the data due to some a priori assumptions (Hecht and Edwards, 1977). The workings of phylogenetic systematics determines the results, not the computer (Wiley, 1981; Churchill et al., 1984, 1985). I re-analyzed three recently published data sets that illustrate problems that can result from misapplied algorithms and character transformations. The examples are taken from the herpetological literature, but similar examples exist in other groups (see discussions in Smith and Hood, 1984; Cracraft, 1987). The first example deals with problems encountered when data sets exceed the ability of the hand-generated method of analysis. Figure 1A is a cladogram taken from a recently published paper on the African/Malagasy frogs in the Old World family Hyperoliidae (Drewes, 1984). In the "Materials and Methods" section Drewes stated that he followed the principles of Hennig (1966). The Hennigian principles

Some errors in systematic theory have arisen by attempts to define things instead of words. The abstract concept of the biological species definition is discussed, together with objections to it. The author shows that "homology" is a theoretical term and that phylogenetic definitions of it are not circular. A number of excellent works are available which discuss aspects of the process of classification. But a clear and rigorous explanation of systematic and phylogenetic method, in which the fundamental concepts are fully elucidated and in which the underlying logic is analysed completely, has yet to be published. This lack is understandable, for the abstract fundamentals are deceptively simple, and applying them in practice is often difficult. For the individual systematist, the only solution seems to be a study of numerous examples, asking repeatedly what is the fundamental justification for the method. But paradoxically, there are so many pitfalls of reasoning, however simple the basic principles may be, that attempts to obtain conceptual rigor through analysis of examples often leads to misconceptions. Hence the current controversies over method. One could only resolve the arguments by showing the particular misconceptions upon which each error rests; but this is impractical, since it would require an exhaustive treatment of the entire scope of abstract thought as it applies to systematics. Nonetheless, some of the problems may be readily disposed of without too detailed a treatment, in that they 1 Although the views expressed here are my own, I must express my deepest gratitude for the criticisms and advice of Walter Bock, Barry R. Wilson, Richard I. Johnson, and, especially, Emst Mayr. Support during the period of research was provided by National Science Foundation Grant NSFG19727. derive from errors of reasoning which may be dealt with apart from fundamental principles. It is hoped that this discussion of one source of error will direct the efforts of systematists toward clarification of their thought. Confusion as to the significance of definitions very often leads to mistakes. This is especially true in the application of typological methods to systematics. Indeed, one might argue that insistence upon purely typological approaches to systematics results as a consequence of using the concept of definition in a nonsensical way. It is things which typology seeks to define. But one does not define a thing, one describes it. Definitions apply only to words, not to the things to which the words correspond. They are simply discussions of how words happen to be used, entailing an analysis of the concepts which the words symbolize, or are proposals to use words in a particular way. Usage being conventional, definitions are perfectly precise, exactly because they say nothing empirical. Because both definitions and descriptions are frequently lists of characteristics of things, they are readily confused, and the idea may arise that definitions and descriptions impose the same kind of limitations on the properties of things that they do on the usage of words. The meaning of a word has nothing whatever to do with the practical problem of identifying the things which may happen to fit the definition. However obvious and indisputable it may be, this point is so often