Phenomena Of Heredity Research Articles

Mendelism in the course of biology of the new ukrainian school

The article draws attention to the discrepancy between the teaching of Mendelism in the secondary school biology course and the level of modern genetics. It is pointed out the shift of emphasis in teaching the laws of inheritance and the simplified understanding of Mendelism by reducing it to three laws. The reason for this can be seen in the unjustified giving to the results obtained by Mendel in the genetic experiment, the status of laws, which, without taking into account modern scientific achievements, uncritically pass from textbook to textbook. It is pointed out the need in the new Ukrainian school, when teaching the basics of classical genetics, to take into account the latest achievements of genetics and suppress Mendelian results not as laws, but as data of a genetic experiment, which became the basis for a paradigm shift in the understanding of the phenomena of heredity – a transition from the idea of fused heredity to the theory of hereditary discreteness material. It is proposed to present Mendel’s achievements to students as one fundamental law of discreteness of heredity, which takes a worthy place in the series of ideas about the discreteness of matter and energy.

GENETIC CODE OF THE CITY

Advances in genetics as a science have led the authors to believe that its methods and approaches can be used in urban research and in justifying decisions on spatial organization and urban development. Using the theoretical and methodological tools of genetics revealed the content of the phenomenon of "genetic top" in urban planning and urban development: understood the key provisions of genetics as a science of heredity – the origin and evolution of organisms, substantiated their feasibility for research on urban history and modern cities; the peculiarities of the genetic method for the study of cities and the role of the phenomenon of heredity for their future are determined. The genetic method is presented as a kind of genetic and aimed at studying the phenomena of development not only in time but also in space, determining the transitions from lower forms of organization of territories (places, settlements) to higher – extremely complex urban systems. It covers: the establishment of initial conditions and the origin of the organism, its main stages, main trends and lines (mutations, modifications) of development. On the example of the city of Lviv the application of certain tools for in-depth understanding of the processes of origin and evolution of the city is revealed. The set of "genes" of the city – spiritual-religious, behavioral-activity and psychological-mental in their various combinations, which form the genotype of the city as connections "man–territory–space–time". It has been confirmed that the city’s genetics (genetic space) is rooted in the past, connected with people, the energy of the Earth and the Universe. "Genetic" research shows that inherited urban differences are a factor that determines urban individuality throughout development, should be taken into account in both research and spatial organization and development of urban systems. The article only initiates certain provisions to substantiate the theory of urban genetics. Future research will determine the evidence in support of the formulated provisions or refute them as false.

Chip Off the Old Block: Generation, Development, and Ancestral Concepts of Heredity.

Heredity is such a fundamental concept that it is hard to imagine a world where the connection between parents and offspring is not understood. Three hundred years ago thinking of the phenomenon of heredity bore on a cluster of distinct philosophical questions inherited from antiquity concerning the nature and origin of substances or beings that lacked biological meaning. We are reminded of this philosophical heritage by the fact that in the 18th century the study of reproduction, embryology and development was referred to as “the science of generation”. It is now clear that reproduction, the biological process by which parents produce offspring, is a fundamental feature of all life on Earth. Heredity, the transmission of traits from parents to offspring via sexual or asexual reproduction, allows differences between individuals to accumulate and evolve through natural selection. Genetics is the study of heredity, and in particular, variation of fundamental units responsible for heredity. Ideas underlying this theory evolved in considerably different and unrelated ways across a number of knowledge domains, including philosophy, medicine, natural history, and breeding. The fusion of these different domains into a single comprehensive theory in 19th century biology was a historically and culturally interdependent process, thus examining genetic prehistory should unravel these entanglements. The major goal of our review is tracing the various threads of thought that gradually converged into our contemporary understanding of heredity.

Epigene Networks: Theory, Models, and Experiment

The article describes a concept of epigene networks that attempts to clarify the phenomenon of heredity and presents the results of long-term studies of the control gene and epigene networks in which the authors used an integrative approach with the tools of mathematical biology, cybernetics, genetic engineering, and bioinformatics. Epigene networks are control gene networks with epigenetic properties or those containing epigenes. By epigene, we mean special hereditary units with at least two modes of functioning of the genes subordinate to them that are capable of maintaining each of the modes in a successive series of generations. Epigenes are the units of functional hereditary memory; they perform a special role in ontogeny and phylogeny. Epigenetic systems can be designed and synthesized experimentally. One such systems is a two-component, stationary epigene with specified and controlled inherited dynamic properties that functions in vivo. Artificial epigenetic constructions can serve as models of the mechanisms of differentiation and cellular memory and can be used as bacterial biosensors. The generalized threshold models of natural and synthetic molecular genetic systems for the control of gene expression have both analytical and predictive value.

Role of genetic in periodontal disease

Genetics is the study and understanding of the phenomena of heredity and variation. A large number of genes are associated with many systemic conditions. Periodontitis is inflammatory condition of periodontium. Periodontium consists of gingiva, periodontal ligament, cementum, and alveolar bone. It is considered being a multifactorial disease. Studies of animals and humans support the concept that a large number of genes' factor may be associated with periodontitis and clearly play a role in the predisposition and progression of periodontal diseases. It has been proven that genetic factors impair inflammatory and immune responses during periodontal diseases. Research on identifying specific genes causing periodontitis may improve and prevent the disease progression. The aim of this article is to focus on genetic risk factors and its influence for the various forms of periodontal disease.

Some Notes on Memory

Some Notes on Memory Samuel Butler (bio) Memory i. Memory is a kind of way (or weight—whichever it should be) that the mind has got upon it, in virtue of which the sensation excited endures a little longer than the cause which excited it. There is thus induced a state of things in which mental images, [End Page 192] and even physical sensations (if there can be such a thing as physical sensation) exist by virtue of association, though the conditions which originally called them into existence no longer continue. This is as the echo continuing to reverberate after the sound has ceased. ii. To be is to think and be thinkable. To live is to continue thinking and to remember having done so. Memory is to mind as viscosity is to protoplasm, it gives a tenacity to thought—a kind of pied-à-terre from which it can, and without which it could not, advance. Thought, in fact, and memory seem inseparable; no thought, no memory; and no memory, no thought. And, as conscious thought and conscious memory are functions of another, so also are unconscious thought and unconscious memory. Memory is, as it were, the body of thought, and it is through memory that body and mind are linked together in rhythm or vibration; for body is such as it is by reason of the characteristics of the vibrations that are going on in it, and memory is only due to the fact that the vibrations are of such characteristics as to catch on to and be caught on to by other vibrations that flow into them from without—no catch, no memory. Antitheses Memory and forgetfulness are as life and death to one another. To live is to remember and to remember is to live. To die is to forget and to forget is to die. Everything is so much involved in and is so much a process of its opposite that, as it is almost fair to call death a process of life and life a process of death, so it is to call memory a process of forgetting and forgetting a process of remembering. There is never either absolute memory or absolute forgetfulness, absolute life or absolute death. So with light and darkness, heat and cold, you never can get either all the light, or all the heat, out of anything. So with God and the devil; so with everything. Everything is like a door swinging backwards and forwards. Everything has a little of that from which it is most remote and to which it is most opposed and these antitheses serve to explain one another. Unconscious Memory A man at the Century Club was falling foul of me the other night for my use of the word “memory.” There was no such thing, he said, as “unconscious memory”—memory was always conscious, and so forth. My business is—and I think it can easily be done—to show that they cannot beat me off my unconscious memory without my being able to beat them off their conscious memory; that they cannot deny the legitimacy of my maintaining the phenomena of heredity to be phenomena of memory without my being able to deny the legitimacy of their maintaining the recollection of what they had for dinner yesterday to be a phenomenon of memory. My theory of the unconscious does not lead to universal unconsciousness, but only to pigeon-holing and putting by. We shall always get new things to worry about. If I thought that by [End Page 193] learning more and more I should ever arrive at the knowledge of absolute truth, I would leave off studying. But I believe I am pretty safe. Reproduction and Memory There is the reproduction of an idea which has been produced once already, and there is the reproduction of a living form which has been produced once already. The first reproduction is certainly an effort of memory. It should not therefore surprise us if the second reproduction should turn out to be an effort of memory also. Indeed all forms of reproduction that we can follow are based directly or indirectly upon memory. It is only the...

Вивчення явища спадковості при трансформації структури в сталях

This article describes the contemporary scientific understanding of the phenomenon of heredity in metals and alloys, of heredity, the mechanism of this phenomenon at various stages of manufacture of parts and its influence on the physicomechanical and performance properties of finished parts.

The language of gene interaction.

> The study of variation and heredity, in our ignorance of the causation of those phenomena, must be built of statistical data, as Mendel knew long ago; but, as he also perceived, the ground must be prepared by specific experiment. The phenomena of heredity and variation are specific questions. That

Ibsen, Strindberg, and Telegony

During the nineteenth century the phenomenon of heredity was of great interest to artists as well as biologists, but its actual dynamics remained mysterious to both. Some felt that the inheritance of characteristics was to be explained on physiological grounds, some on psychic, and some on a combination of the two. A writer inclined toward scientific materialism like Zola naturally emphasized the physical interpretation of this phenomenon, but Ibsen and Strindberg found the possibility of heredity through psychic means, called telegony by August Weismann, more useful for their aesthetic concerns. Their plays show many varieties of this phenomenon, using telegony in ways related both to contemporary scientific speculation and to a long literary tradition, in which a key work was Goethe'sDie Wahlverwandtschaften.

A single principle for sex determination in insects.

On September 27, 1870, Gregor Mendel wrote to the famous botanist Nägeli in Zurich. In his letter, he suggested that sex determination might prove to be a phenomenon of heredity and segregation. But, as with his previous discovery of the principles of heredity, no attention was paid to his idea.

Genetics

The basic principles of inheritance were not established as a consequence of an immense accumulation of descriptive evidence. In this respect, the history of genetics differs from that of many other branches of biology. Before Mendel's conceptual tour de force and indeed, until his rules of diploid inheritance were rediscovered at the turn of the century, the phenomenon of heredity remained a mystery. A number of plant hybridists grappled with the apparently inscrutable properties of variation and even Darwin, the most incisive and comprehensive thinker among nineteenth-century biologists, remained baffled. Nevertheless, in the space of some 80 years, a staggering explosion in our understanding of heredity and in the development of analytical techniques has propelled the science of genetics into the middle of the biological stage where it plays a role rather analogous to that of atomic physics vis-à-vis the physical sciences.

August Weismann and a break from tradition

In 1892 August Weismann (1834-1914) presented to the scholarly world a remarkable theory which in a single sweep explained the diverse biological phenomena of heredity, development, regeneration, sexual reproduction, mitotic division, and Darwin's theory of evolution by natural selection. Only after a seasoned career had Weismann arrived at this comprehensive master plan-his germ-plasm theory.' He had completed his medical studies at G6ttingen in 1856 with a prizewinning essay on the source of hippuric acid in herbivors; he had worked briefly as an assistant at a chemical laboratory in Rostock; he had served as a military and private physician; he had returned to histological studies under Rudolph Leuckart (1822-1898) at Giessen and, after the completion of his "Habililationsschrift" on the metamorphosis of insects in 1863, he had become docent in zoology and comparative anatomy at Freiburg im Breisgau. At this university in the southwestern corner of Germany, Weismann had quickly risen through academic ranks to full professor and director of the zoological institute. Despite sustained eye trouble, which seriously curtailed his microscopic studies, he had completed by 1876 a series of monographic studies on metamorphosis in butterflies and in Axolotl with the object of examining the efficacy of natural selection. Furthermore, he had devoted considerable effort to investigating the ecology of and the parthenogenesis among the Clodocera of the Bodensee, and by 1880 he had begun studying the origin of the sexual cells in Hydrozoa. It was during the

Sex factors and viruses.

At this Symposium we are remembering and honouring the great and revolutionary discoveries of Gregor Mendel, presented to the world 100 years ago this year, which for the first time expressed the basic phenomena of heredity in a concise, analytical and, above all, numerical form and thus laid the foundation of the science of genetics. However, as the title of this symposium implies, we are not met here merely in adulation of Mendel’s genius but rather to review and discuss the fruits which have now matured on the tree which he planted. I think some of these fruits would seem very strange and incomprehensible to Mendel, for over the last two decades we have witnessed another revolution in genetics as dramatic and as pregnant with new potentialities as that of 100 years ago. The basic ingredients of this revolution were, first, the disclosure of systems of genetic recombination in micro-organisms, and especially in bacteria and their viruses, which enormously increased the resolution of genetic analysis; and, secondly, the elucidation by Watson & Crick, in 1953, of the physico-chemical structure of the genetic material, deoxyribonucleic acid—undoubtedly the most important and provocative biological discovery since Mendel. As a result we are now recapitulating the cytogenetical studies and correlations which marked the turn of the century, but this time the precision and refinement of our tools and techniques have increased more than 1000-fold so that we are looking at genetic behaviour and interaction at the level of molecular structure. In this lecture I would like to discuss what, from the Mendelian viewpoint, must be one of the most bizarre forms of sexual heredity, namely, the process of conjugation and genetic recombination in the bacterium Escherichia coli . My reasons for choosing this rather esoteric topic, apart from personal interest, are three. First, the whole mechanism of sexuality in this organism is mediated and controlled by a new kind of genetic element called the sex factor which, like some temperate bacteriophages, is able to exist in alternative states in the cell, either free in the cytoplasm or as an integral part of the bacterial chromosome, and which can properly be construed as a virus with a novel mode of infectivity, as I hope to show. Secondly, a number of essentially similar elements have recently been discovered in bacteria, masquerading under such different disguises as the genetic determinants of antibiotic substances called colicins or as carriers of transmissible drug resistance, so that the sex factor is far from being a unique entity among the bacteria. Thirdly, genetic interactions occur between the sex factor and the bacterial chromosome which confer great flexibility on this system. Some of the situations which are generated by these interactions mimic those found in the cells of higher organisms so that it is possible to construct plausible, though very speculative, models for the evolution of more stable and highly organized genetic systems.

FOREWORD

The two main groups brought together by this year's program were geneticists and anthropologists, both of which study the evolution of man. The ultimate purpose of science, perhaps, is to assist man in understanding himself and his place in the universe. All branches of science, even those studying celestial bodies or the structure of the atom, eventually contribute to this purpose. But the sciences most immediately concerned with man are anthropology and biology, which study him as a living organism and a social being. For nearly two centuries anthropology and biology have developed almost independently, although both have been profoundly influenced by such fundamental discoveries as Darwin's theory of evolution and his finding that man is a part of nature. In our century, the development of genetics, which studies the phenomena of heredity and variation, has caused a gradual drawing together of biological and anthropological research.

Species and Adaptations

MR. BATESON'S address to the American Association at Toronto last December, which was published in NATURE of April 29, exhibits features of the same kind as those which were evident in his address to the British Association in Australia in 1914. In the Australian address he maintained that the effect of the discoveries and investigations in recent years in the phenomena of heredity and variation was greatly to increase the difficulty of understanding the origin of any characters which were new in the proper sense of the word. He went so far as to suggest that all characters which have appeared in the course of evolution may have been present in the protoplasm Or nuclear structure of the original unicellular forms from which later forms, including man, have descended, all apparently new characters having been due to loss of inhibiting factors and segregation of various simpler combinations from the original complex. Now Mr. Bateson again declares himself an agnostic with regard to the evolution of species, and in spite of all modern discoveries, or because of them, states that we are farther than ever from any satisfactory explanation of the evolution of a new species, or of two or more species, from a single ancestral species.

An Introduction to a Biology, and Other Papers

SINCE the advent of natural selection the mechanistic interpretation of Nature has on the. whole steadily gained ground among biologists., The trend has been more and more towards the translation of vital phenomena in terms of physics and chemistry. Much of modern investigation, such as the discovery of artificial parthenogenesis or the establishing of the Mendelian principles among the phenomena of heredity, has undoubtedly strengthened the mechanistic position. Yet to all action succeeds reaction. To-day there is an evident tendency in many quarters to. cast on one side the mechanistic., interpreter and seek out other prophets. The note sounded thirty years ago by the acute and critical intellect of Samuel Butler is finding echoes among. biological workers. Such a one was the author of this book.. The “Introduction to a Biology” was designed, we are told, to direct attention to the failure of modern interpretative biology and to suggest the direction in which an understanding of life may be sought. Unhappily the work is but a fragment cut short by the author's premature death.

The Evolution of a Botanical Problem

FROM the beginning of man's thoughtful consideration of natural processes, the phenomenon of sexual reproduction, with the associated phenomena of heredity, have persistently engaged his keenest interest. The primary fact of the necessary concurrence of two individuals in the production of offspring was, in the case of animals, recognized from the beginning. The equivalent phenomenon was not established for plants until the end of the seventeenth century. At this time, however, little more was known of the essential features of the sexual process in animals than had beenfamiliar to Assyrians, Egyptians and Greeks twenty centuries before. Of the additions made since 1700 to our knowledge of sexual reproduction, of its varied types and of the associated phenomena, no mean share has been contributed by botanical investigators. Noteworthy among such contributions are the work of Koelreuter and Mendel in the production and systematic study of plant hybrids, and the early work of Pfeffer on the chemotactic response of spermatozoids. Of more recent work we may cite that of the plant cytologists on apogamy and apospory, on multi-nucleate sexual eells or gametes, and on the long-delayed nuclear fusion in the sexual reproduction

Societies and Academies

MANCHESTER. Literary and Philosophical Society, October 3.— The president, Prof. F. E. Weiss, gave an address on recent researches on heredity in plants. After mentioning the work of earlier investigators, Prof. Weiss referred to the experiments of Mendel on the crossing of different strains of peas. From the results Mendel deduced the two fundamental laws of heredity: first, the dominance of certain unit characters in the first hybrid generation, and, secondly, the segregation of the dominant and recessive characters in the second hybrid generation. This latter law, though not its numerical ratios, was independently discovered by Naudin. These discoveries remained almost unnoticed for half a century, until de Vries, Correns, Bateson, and others brought them prominently before biologists at the beginning of the century. Confining himself to the phenomena of heredity in plants, Prof. Weiss dwelt upon some of the investigations of Correns and Bateson on colour inheritance in Mirabilis jalapica and sweet peas, and referred also to his own experiments in crossing the scarlet and blue forms of the common Pimpernel. The resultant cross was completely scarlet, like one of the parents, but in the subsequent generation 25 per cent, of the offspring were pure blues. The same result was obtained by crossing the blue form with pollen from a pink variety of Pimpernel, blue being recessive in the first hybrid generation. Prof. Weiss also dealt with the numerical ratios exhibited in the inheritance of paired characters, and with some of the more complex manifestations, such as the appearance of coloured flowers as the offspring of two white parents. Dealing with the analysis of hybrid plants, he referred to his experiments with Geum intermedium, the cross between the common and water avens, a hybrid not uncommonly met with in the limestone dales of Derbyshire. This plant exhibits in the size, colour, and shape of its flowers an intermediate condition between its two parents, and is thus easily distinguished from either. The flowers of the hybrid possess both the yellow plastids of the common avens and the red sap (anthocyanin) of the water avens. When pollinated with its own pollen, this very fertile hybrid gives rise to plants some of which have red flowers with no trace of yellow, while others are yellow with no red sap, and, in addition, a number of plants with pure white flowers were obtained. A similar “throwing” of white flowers was observed in the offspring of the hybrid between the primrose and the oxlip. The question of the determination of sex has also been attacked from the botanical point of view by Correns with some success, and his results, on the whole, tend to confirm the view that this problem may yet be satisfactorily solved on Mendelian lines.

Elemente der exakten Erblichkeitslehre

WITHIN the last few years the output of exact experimental work upon phenomena of heredity has been very large, and the progress made, as compared with that of the previous forty years, has been astounding. In England it has chiefly been produced by investigator? who have strictly segregated themselves either to the Mendelian or the bio-metrical schools, and who as a rule seem unable to icalise the merits of the work of their rivals. One may pause in astonishment on reading, in a recent work issued by the head of the Mendelian school, that Of the so-called investigations of heredity pursued by extensions of Gallon's non-analytical method and promoted by Prof. Pearson and the English bio-metrical school it is now scarcely necessary to speak. That such work may ultimately contribute to the development of statistical theory cannot be denied, but as applied to the problems “of heredity the effort has resulted only in the concealment of that order which it was ostensibly undertaken to reveal. … With the discovery of segregation, it became obvious that methods dispensing with individual analysis of the material are useless.” Elemente der exakten Erblichkeitslehre. Deutsche wesentlich Erweiterte Ausgabe in Fünfundzwanzig Vorlesungen. By W. Johannsen. Pp. vi + 516. (Jena: Gustav Fischer, 1909.) Price 9 marks.

Hering's Theory of Heredity, and its Consequences

UNTIL lately I supposed, with most biologists, that the phenomena of heredity and variation were facts which we were quite unable to explain. But having had occasion to study the subject once more, I have found in Prof. Hering's1 address on “Memory as a General Function of Organised Matter,” delivered to the Imperial Academy of Sciences at Vienna on May 30, 1870, the germ of a theory which simplifies everything, and throws quite a new light on the problem of variation. In fact, when carried to its full extent, it reduces our difficulties almost to the ever-lasting mystery of the nature and mode of action of mind, a mystery which can never be solved.