Theory Of Inheritance Research Articles

Niche construction on Bali: the gods of the countryside

Human niche construction encompasses both purely biological phenomena, such as the evolution of lactose tolerance, and dual inheritance theory, which investigates the transmission of cultural information. But does niche construction help to explain phenomena in which conscious intention also plays a role? The creation of the engineered landscape of Balinese rice terraces offers a test case. Population genetic analysis and archaeological evidence are used to investigate whether this phenomenon emerged historically from trial and error by generations of farmers, or alternatively was designed by Bali's rulers. In light of strong support for the former hypothesis, two models are developed to explore the emergence of functional structure at both local and global scales. As time goes forward and selected patterns of irrigation schedules are implemented, local variation in rice harvests influences future decisions by the farmers, creating a coupled human-natural system governed by feedback from the environment. This mathematical analysis received a measure of empirical support when government agricultural policies severed the local feedback channels, resulting in the almost instantaneous collapse of rice harvests. The historical process of niche construction may also have included an evolution of religious consciousness, reflected in the beliefs and practices of the water temple cult.

Bio-Legal History, Dual Inheritance Theory and Naturalistic Comparative Law: On Content and Context Biases in Legal Evolution

Abstract In this article, I take a closer look at what contemporary evolutionary approaches to human behavior and culture could have to offer comparative legal theory. I shall argue that these contemporary evolutionary approaches have reached a sufficient level of both sophistication and agreement to warrant their cautious re-inclusion into comparative legal theory. The article is structured as follows. In the first section I will introduce the concept of “bio-legal histories” as a new, but possibly better, variant – inspired by evolutionary psychology – of the much older idea that the “psychic unity of humankind” leads to “universal comparative law.” The contemporary evolutionary approaches to human behavior (and culture) underlying these views – evolutionary psychology and cultural epidemiology – will then be contrasted to dual inheritance theory – a contemporary evolutionary approach to human behavior that is, I believe, better geared towards understanding the mechanisms leading to cultural diversity. I aim to show that the differences between these approaches and their counterparts in the comparative law literature are in large part due to their differing views on the relative likely importance of two different classes of cultural evolutionary forces: content-based biases and context-based biases. This will also allow me to express some doubts as regards memetic approaches to (comparative) law and the application of Generalized Darwinism to evolutionary economics. Finally, some possible implications of the dual inheritance theoretical approach for comparative law are briefly discussed.

Autonomic dysregulation as a novel underlying cause of mitral valve prolapse: a hypothesis.

SummaryMitral valve prolapse is a common valvular abnormality that is caused by myxomatous degeneration, characterized macroscopically by leaflet thickening and redundancy accompanied with histologically marked proliferation of the spongiosa and mucopolysaccharide acid replacement of leaflet collagen in the prolapse leaflets. Nevertheless, the discrepant natural history and various concomitant syndromes cannot be explained completely by the current genetic autosomal dominant inheritance theory. In addition, autonomic dysregulation has been commonly reported in mitral valve prolapse, but has never been indicated as a major underlying cause. This article attempts to interpret the occurrence of primary pathology and progression in mitral valve prolapse on a common basis of improper autonomic tone. The imbalanced background of autonomic nervous firing leads to disharmonized synthetic/catabolism balance in the extracellular matrix, disrupted transition in the interstitial cellular component and invalided anti-inflammatory pathway in the endothelium, which trigger and accelerate the progression of this condition. Such a hypothesis not only unifies the seemingly disparate syndromes and valvular disorder, but also has implications for future biopharmaceutical and mechanical treatment.

Mendel's Theatre: Heredity, Eugenics, and Early Twentieth-Century American Drama (review)

Reviewed by: Mendel's Theatre: Heredity, Eugenics, and Early Twentieth-Century American Drama Susan Currell Tamsen Wolff. Mendel's Theatre: Heredity, Eugenics, and Early Twentieth-Century American Drama. Basingstoke, UK: Palgrave Macmillan, 2009. Pp. 278, illustrated. $90.00 (Hb). The title of Tamsen Wolff's book comes from a mechanical display model called "Mendel's Theatre" that was used by the eugenic movement to teach theories of genetic inheritance to early-twentieth-century Americans. This performance was played to those who were to become the chief actors and directors in an offstage drama: potential field-workers who would go into communities to help direct future progress towards human betterment. As this audience was mostly female, eugenicists attempted to convey scientific concepts clearly; in order to make visible what was invisible, they relied heavily on performance and theatricality. "Mendel's Theatre" was shaped like a proscenium stage embedded with a rolling scroll on which three acts "detail[ed] with pictures and dolls the inexorable drama of the Mendelian inheritance of human hair and skin color" (61). The analogy between the eugenicist dramatization of the theories of inheritance and modern dramaturgy continues throughout Wolff's well-researched, fascinating, and extremely convincing book, which argues that the eugenic movement was inherently theatrical and that modern drama engaged with (and was enlivened by) both the ideas and the theatricality of that movement. The book is an original and compelling dramatization in both theme and style: tracing the origins of dramatic fascination with the theme of heredity, Wolff builds her own ancestral tree, beginning with a chapter on the "Predecessors" of American eugenic drama–Ibsen, Strindberg, and Shaw–and ending with a chapter titled "A Genealogy of American Theatre." Paying clear attention to the ambiguities, ambivalences, and downright contradictions of eugenic thought in the early twentieth century, Wolff shows how dramatists adapted and adjusted their stagecraft to present prevailing hereditarian ideas. For Ibsen and Strindberg (whose pre-Mendelian era plays connected them to a more confused or complex neo-Darwinism, such as environmental or Lamarckian eugenics), this was more a thematic concern to make visible in the present the impact [End Page 595] of an unseen past. Subsequently a major goal of modern drama, revealing the hidden (or recessive traits and genes) was a similar concern for eugenic pedagogy, as shown in Mendel's Theatre. Once Mendelian genetic theory was rediscovered in 1900, the shift in eugenic thought also emerged in a dramaturgical shift, most clearly in the plays of George Bernard Shaw. Developing his own theory of "Creative Evolution" (37), Shaw built on Ibsen and Strindberg to stage explicit dramas of eugenic idealism (however confused it may have been at the time), and those dramas subsequently influenced the American dramatists Eugene O'Neill and Susan Glaspell, whose works and engagement with eugenics are the central focus of the book. The reception and production of hereditarian theatre in America was particularly strong, Wolff argues, because eugenic thought was widely accepted, along with progressive discourses about the future of the American population. In many ways, she correctly points out, America was the stage on which the eugenic drama would unfold. Wolff provides a useful outline of the development of the eugenic movement in America, and, while much of this development has been detailed before, she stays focused on its central relationship to dramatic developments. Chapters on Glaspell's The Verge (1921) and O'Neill's Strange Interlude provide close readings of both the themes and stage-craft associated with prevailing eugenic ideas and ideologies, showing that the very contradictions in such thought operated to make complex and ambiguous stage dramas. While inflected by eugenic thought, The Verge also dramatized and undercut a rhetoric that would deny women agency and put unsustainable faith in the evidence of the unseen and unknowable. Similarly, Strange Interlude–called by one contemporary critic the "Eugenic O'Neill Baby" (qtd. in Wolff 142)–enacted the production of a eugenic child and its consequences in a nine-act drama that was incredibly popular at the time (though never since). As in Ibsen and Strindberg, the problem of free will created a dramatic tension with the eugenic message of unseen forces directing human behaviour...

The evolutionary analysis of human behaviour: its potential to increase plant conservation success

Humans derive most of their well-being from plants, a self renewing natural resource. Yet human activities aimed at increasing well-being are threatening self renewal of some of these species. Some are directly threatened by over exploitation. Most become threatened as an unforeseen consequence of other activities principally agriculture, commerce, industrialisation and the manufacture and use of artificial fertilisers. The evidence suggests that the evolutionary need for reproductive success in humans has led our use of natural sources to be unsustainable throughout our species history. The need to acquire resource to achieve mate selection remains the same today as for our earliest relatives. Only the extent and rate of acquisition has changed in recent times and with it the environment and the diversity of plants that survive. Throughout our history, human ingenuity has often been required to rebalance the demand for plant derived benefits for well-being with their supply. Both technical and social ingenuity have been used to achieve the necessary outcome. The targets set within the Global Strategy for Plant Conservation reflect the need for both social and technical ingenuity if the loss of plant diversity is to be halted, with 10 of the 16 targets focussing on social change and only 4 requiring technical innovation. Yet, inspection of the literature shows little use is made of the evolutionary analysis of human behaviour (evolutionary psychology, human behavioural ecology and dual inheritance theory) in the design of projects seeking plant conservation. This paper attempts to begin to close this gap.

How Far Will We See in the Future?

How Far Will We See in the Future?

Lysenko rising

Lysenko rising

Giuseppe Sergi, "champion" of Darwinism?

The Italian anthropologist, psychologist and evolutionist Giuseppe Sergi (1841-1936) may be regarded in some respects today as an "atypical" Darwinist, but, almost paradoxically, he was considered a "champion" of Darwinism by colleagues and commentators of his own time. Probably, two aspects of his work are responsible for this apparent anomaly: his faith in the so-called soft inheritance and his claims regarding a theory concerning the polyphyletic origin of human races. The soft inheritance theory, however, was needed by Sergi to support ideas regarding the complexity of inheritance in man, a fact that, in his opinion, could not completely be put down to mechanical laws, and polygeny was useful when trying to rectify the problem concerning the incompleteness of the fossil record. In both cases, it is possible to show that he was involved in supporting Darwinian theory during the most severe crisis of its consensus in Italy and at International level, between the end of the 19th century and the beginning of the 20th. Finally, the apparent unorthodox features which can be found in Sergi's ideas appear to be, in Kuhnian terms, ad hoc hypotheses put forward by Sergi himself in order to support the paradigm.

Is Lamarckian evolution relevant to medicine?

Background200 years have now passed since Darwin was born and scientists around the world are celebrating this important anniversary of the birth of an evolutionary visionary. However, the theories of his colleague Lamarck are treated with considerably less acclaim. These theories centre on the tendency for complexity to increase in organisms over time and the direct transmission of phenotypic traits from parents to offspring.DiscussionLamarckian concepts, long thought of no relevance to modern evolutionary theory, are enjoying a quiet resurgence with the increasing complexity of epigenetic theories of inheritance. There is evidence that epigenetic alterations, including DNA methylation and histone modifications, are transmitted transgenerationally, thus providing a potential mechanism for environmental influences to be passed from parents to offspring: Lamarckian evolution. Furthermore, evidence is accumulating that epigenetics plays an important role in many common medical conditions.SummaryEpigenetics allows the peaceful co-existence of Darwinian and Lamarckian evolution. Further efforts should be exerted on studying the mechanisms by which this occurs so that public health measures can be undertaken to reverse or prevent epigenetic changes important in disease susceptibility. Perhaps in 2059 we will be celebrating the anniversary of both Darwin and Lamarck.

Like Grandfather, Like Grandson: Erasmus and Charles Darwin on evolution

Last year (2009) marked the bicentenary of Charles Darwin's birth and the sesquicentenary of The Origin of Species. This article examines the influence of Erasmus Darwin on Charles's evolutionary thought and shows how, in many ways, Erasmus anticipated his much better-known grandson. It discusses the similarity in the mindsets of the two Darwins, asks how far the younger Darwin was exposed to the elder's evolutionary thought, examines the similarities and differences in their theories of evolution, and ends by showing the surprising similarity between their theories of inheritance. Erasmus's influence on Charles is greater than customarily acknowledged, and now is an opportune time to bring the grandfather out from behind the glare of his stellar grandson.

THE KNOWLEDGE INHERITANCE THEORY OF DISTRIBUTIVE JUSTICE

This article criticises the ‘knowledge inheritance theory of distributive justice’ presented by Gar Alperovitz and Lew Daly in their Unjust Deserts: How the Rich Are Taking Our Common Inheritance and Why We Should Take It Back; Wealth and Inequality in the Knowledge Economy (New York: The New Press, 2008). The authors claim that since innovation depends far more on accumulated knowledge than on any individual's contribution, most resulting wealth is deserved equally by all members of society. Their redistributive conclusion is not justified. Illegitimately applying the concept of justice to contexts where it is at best metaphorical, the ‘knowledge inheritance theory’ massively undervalues the role of individual intellectual activity, and relies on confusions concerning the nature of society, rights, causality, and gifts.

The foundation of extranuclear inheritance: plastid and mitochondrial genetics

In 1909 two papers by Correns and by Baur published in volume 1 of Zeitschrift für induktive Abstammungs- und Vererbungslehre (now Molecular Genetics and Genomics) reported on the non-Mendelian inheritance of chlorophyll deficiencies. These papers, reporting the very first cases of extranuclear inheritance, laid the foundation for a new field: non-Mendelian or extranuclear genetics. Correns observed a purely maternal inheritance (in Mirabilis), whereas Baur found a biparental inheritance (in Pelargonium). Correns suspected the non-Mendelian factors in the cytoplasm, while Baur believed that the plastids carry these extranuclear factors. In the following years, Baur's hypothesis was proved to be correct. Baur subsequently developed the theory of plastid inheritance. In many genera the plastids are transmitted only uniparentally by the mother, while in a few genera there is a biparental plastid inheritance. Commonly there is random sorting of plastids during ontogenetic development. Renner and Schwemmle as well as geneticists in other countries added additional details to this theory. Pioneering studies on mitochondrial inheritance in yeast started in 1949 in the group of Ephrussi and Slonimski; respiration-deficient cells (petites in yeast, poky in Neurospora) were demonstrated to be due to mitochondrial mutations. Electron microscopical and biochemical studies (1962-1964) showed that plastids and mitochondria contain organelle-specific DNA molecules. These findings laid the molecular basis for the two branches of extranuclear inheritance: plastid and mitochondrial genetics.

Genetic analysis: a history of genetic thinking

1. Introduction 2. From reproduction and generation to heredity 3. Faktoren in search of meaning 4. The chromosome theory of inheritance 5. Genes as the atoms of heredity 6. Increasing resolving power 7. Deducing genes from traits, inducing traits from genes 8. What is true for E. coli is not true for the elephant 9. Concluding comments bibliography.

Coalescent under the evolution of coadaptation

Adaptation to novel environments arises either from new beneficial mutations or by utilizing pre-existing genetic variation. When standing variation is used as the source of new adaptation, fitness effects of alleles may be altered through an environmental change. Alternatively, changes in epistatic genetic backgrounds may convert formerly neutral mutations into beneficial alleles in the new genetic background. By extending the coalescent theory to describe the genealogical histories of two interacting loci, I here investigated the hitchhiking effect of epistatic selection on the amount and pattern of sequence diversity at the linked neutral regions. Assuming a specific form of epistasis between two new mutations that are independently neutral, but together form a coadapted haplotype, I demonstrate that the footprints of epistatic selection differ markedly between the interacting loci depending on the order and relative timing of the two mutational events, even though both mutations are equally essential for the formation of an adaptive gene combination. Our results imply that even when neutrality tests could detect just a single instance of adaptive substitution, there may, in fact, be numerous other hidden mutations that are left undetected, but still play indispensable roles in the evolution of a new adaptation. We expect that the integration of the coalescent framework into the general theory of polygenic inheritance would clarify the connection between factors driving phenotypic evolution and their consequences on underlying DNA sequence changes, which should further illuminate the evolutionary foundation of coadapted systems.

Darwinism in the twenty-first century

Darwin (1859) formulated a comprehensive explanation of evolution by natural selection, including a molecular theory of inheritance and the realization that novel adaptive traits could originate by environmental induction. While the twentieth century was the age of the gene in evolutionary biology, the twenty-first century promises to be the age of the environment: developmental genetics, alongside Mendelian transmission genetics, and a growing appreciation of environmental effects on organisms, represents a return to Darwin’s original view of how adaptive evolution works.

Laboratory Exercises To Examine Recombination & Aneuploidy inDrosophila

[ILLUSTRATION OMITTED] Chromosomal aneuploidy, a deviation from an exact multiple of an organism's haploid chromosome number, is a difficult concept for students to master. Aneuploidy arising from chromosomal non-disjunction (NDJ) is particularly problematic for students, since it arises in the context of meiosis, itself a challenging subject. Students learning NDJ are forced to actively apply their knowledge of normal meiosis, often revealing previously unapparent deficits in their understanding. Teaching NDJ is thus an important opportunity for students to review and apply their skills in modeling meiosis. Despite this opportunity, standard methods for teaching NDJ are passive. While experiments illustrating recombination mapping, sex-linkage, and other core genetics concepts are readily available for high school and undergraduate genetics courses, simple exercises demonstrating NDJ are not. This is regrettable, for non-disjunction is not only medically important but also historically significant as the original proof for the chromosomal theory of inheritance (Bridges, 1916). Presented here is a straightforward method to detect NDJ of the sex chromosomes in Drosophila in the context of laboratory exercises to examine recombination of sex-linked loci. The exercises presented here allow for detecting maternal and paternal NDJ events within a single cross, an advantage since the use of standard markers obscures paternal NDJ events (Bridges, 1916). An additional advantage of this method is that it easily allows for recombination mapping with recessive alleles in trans as well as in cis. This method allows students to simultaneously investigate recombination and aneuploidy with live organisms, and as such is complementary to theoretical methods of teaching recombination and NDJ. The exercises presented here are based on a Drosophila virginizing system that has recently been developed as a method to perform teaching crosses without the need for collecting virgins manually (Venema, 2006). This system employs a modified Y chromosome that harbors a conditional, dominant lethal mutation: a regulatory sequence that is activated in response to heat connected to a protein called head involution defective, or hid that activates programmed cell death. Since this modified Y chromosome (abbreviated as Y{hs-hid}) is present only in males, temporarily raising the temperature of a Y{hs-hid} Drosophila culture during larval stages will cause all males to undergo systemic apoptosis and die. Female larvae, however, survive the heat shock and remain virgin after hatching since there are no surviving males to mate with (Venema, 2006). The use of this system is of great advantage for educators in that large numbers of virgins can be obtained without scoring or segregating young female flies. This ability to use large numbers of flies in pedagogical crosses also facilitates finding the results of rare genetic events in the progeny. (1) Venema (2006) describes a scheme for recombination mapping between autosomal loci using this system; however, recombination mapping of sex-linked loci in Drosophila is more convenient for high school or introductory-level university courses. Additionally, examining recombination between sex-linked loci allows for the simultaneous detection of chromosomal NDJ events in the progeny, since some Drosophila sex chromosome aneuploids are viable (Table 1). Four possible exercises are presented: two versions of a dihybrid testcross and two versions of a three-point testcross. The dihybrid testcross exercises map sex-linked loci with the recessive mutant alleles either together as a parental genotype (i.e., recessive alleles in cis) or with recessive mutations inherited from both parents (recessive alleles in trans). Similarly, the options for the three-point testcross are mapping the three loci with mutant alleles all in cis, or with two in cis, and the third in trans. The dihybrid or three-point testcross options allow for instructors to choose the exercises of appropriate complexity for their particular grade level and learning objectives. …

Toward a Modern Revival of Darwin's Theory of Evolutionary Novelty

Darwin proposed that evolutionary novelties are environmentally induced in organisms “constitutionally” sensitive to environmental change, with selection effective owing to the inheritance of constitutional responses. A molecular theory of inheritance, pangenesis, explained the cross-generational transmission of environmentally induced traits, as required for evolution by natural selection. The twentieth-century evolutionary synthesis featured mutation as the source of novelty, neglecting the role of environmental induction. But current knowledge of environmentally sensitive gene expression, combined with the idea of genetic accommodation of mutationally and environmentally induced change, supports a revival of Darwin's original theory that is consistent with modern molecular and population genetics.

Defeasible inheritance systems and reactive diagrams

Inheritance diagrams are directed acyclic graphs with two types of connections between nodes: x → y (read x is a y) and x 6→ y (read as x is not a y). Given a diagram D, one can ask the formal question of “is there a valid (winning) path between node x and node y?” Depending on the existence of a valid path we can answer the question “x is a y or ”x is not a y. The answer to the above question is determined through a complex inductive algorithm on paths between arbitrary pairs of points in the graph. This paper aims to simplify and interpret such diagrams and their algorithms. We approach the area on two fronts. (1) Suggest reactive arrows to simplify the algorithms for the winning paths. (2) We give a conceptual analysis of (defeasible or nonmonotonic) inheritance diagrams, and compare our analysis to the “small” and “big sets” of preferential and related reasoning. In our analysis, we consider nodes as information sources and truth values, direct links as information, and valid paths as information channels and comparisons of truth values. This results in an upward chaining, split validity, off-path preclusion inheritance formalism of a particularly simple type. We show that the small and big sets of preferential reasoning have to be relativized if we want them to conform to inheritance theory, resulting in a more cautious approach, perhaps closer to actual human reasoning. We will also interpret inheritance diagrams as theories of prototypical reasoning, based on two distances: set difference, and information difference. We will see that some of the major distinctions between inheritance formalisms are consequences of deeper and more general problems of treating conflicting information. It is easily seen that inheritance diagrams can also be analysed in terms of reactive diagrams as can all argumentation systems. AMS Classification: 68T27, 68T30

Mapping Linked Genes in Drosophila melanogaster Using Data from the F2 Generation of a Dihybrid Cross

Drosophila melanogaster is a commonly utilized organism for testing hypotheses about inheritance of traits. There is a wide variety of mutants of Drosophila that demonstrate effectively both dominant and recessive traits, as well as autosomal and X-linked inheritance (Flagg, 2005; Winchester & Wejksnora, 1996). Students in both high school and university labs study the genetics of inheritance by analyzing offspring of appropriate Drosophila crosses to determine inheritance patterns, including gene linkage. However, most genetics investigations with Drosophila analyze offspring patterns of the F2 generation of dihybrid crosses to determine that genes are linked but do not calculate the map units between the linked genes (College Board, 2001; Mertens & Hammersmith, 2007; Scott, 2001). Calculating map units between linked genes is most straightforward when testcross data is used (Brooker, 2005; Russell, 2006). However, setting up a testcross is not trivial. Constructing a testcross in Drosophila requires obtaining an F1 virgin female fly to mate with a homozygous recessive male fly in order to produce the subsequent generation for analysis of traits. In a teaching lab setting in which there are severe constraints on lab time, students have great difficulty in obtaining virgin F1 females to set up the testcross to generate data for mapping. This article describes how to use F2 data generated from an F1 sibmate cross to determine map distances in linked genes. Lab Method & Data Analysis Drosophila crosses with virgin parentals are either set up by the instructor (Flagg, 2005) or are ordered from a commercial supplier (Carolina Biological Supply, Burlington, NC or Ward's Natural Science, Rochester, NY). These crosses can be set up either as a coupling cross or as a repulsion cross. The coupling cross is performed by crossing a wild-type fly to one that has both mutant phenotypes in the homozygous form. An example would be crossing a wild type fly to one with sepia eyes and ebony body. The repulsion cross is performed by crossing one homozygous mutant with another. An example of this would be crossing a fly with sepia eyes to one with an ebony body. After one week, the parentals are removed and the larvae are allowed to hatch into the F1 generation. Students analyze the F1 generation of the appropriate Drosophila cross to determine which traits are dominant and which are recessive. The F1 generation of this Drosophila cross is then allowed to sibmate in a new vial of Drosophila media. After one week, the F1 generation is removed from the vial and the larvae are allowed to remain. After an additional week, the F2 generation is removed, anesthetized or immobilized, and sorted according to sex and phenotype (College Board, 2001; Flagg, 2005; Mertens & Hammersmith, 2007; Scott, 2001; Winchester & Wejksnora, 1996). Once data are obtained, students use chi-square analysis (College Board, 2001; Brooker, 2005; Russell, 2006) to determine if the genes are linked or independently assorting. They hypothesize that the F2 generation should produce a 9:3:3:1 ratio and use chi-square analysis to determine if the offspring fit the hypothesized ratio (College Board, 2001; Brooker, 2005; Russell, 2006). To make this exercise more investigative, students can develop hypotheses based upon their knowledge about the chromosomal theory of inheritance, gene linkage, and crossing over (Brooker, 2005) before they count the F2 generation. Once students understand coupling and repulsion crosses, they can predict the outcomes of the F2 generations in the coupling and repulsion crosses for linked genes, if no crossing over has occurred. Students should be able to determine that in a coupling cross, the F2 should produce no offspring demonstrating a single recessive trait unless crossing over occurred. Further investigation should allow the students to hypothesize that in the repulsion cross, the double recessive offspring should not be seen in the F2 unless recombination has occurred. …

Ensuring product quality in hardware-manufacturing technologies

This article attempts to solve problems related to ensuring product quality in hardware manufacturing operations by using principles from the theory of technological inheritance. Measures are proposed to eliminate undesirable technological inheritance that lowers product quality and examples are given to illustrate their practical use in hardware production.