150 Jahre Mendel

The monk and his legacy: 150 years of Mendel The paper demonstrates how the experiments of Gregor Johann Mendel (1822–1884) with plant hybrids in the late 1860s revolutionized modern biology. It also shows how the commemoration of his anniversaries during the 20th century reflected the change of scientific epochs determined by the growth of genetics and related fields.     

Instructors' practices in and attitudes toward teaching ethics in the genetics classroom

There is strong consensus among educators that training in the ethical and social consequences of science is necessary for the development of students into the science professionals and well-rounded citizens needed in the future. However, this part of the curriculum is not a major focus of most science departments and it is not clear if, or how, students receive this training. To determine the current status of bioethics education of undergraduate biology students in the United States, we surveyed instructors of introductory genetics. We found that there was support for more ethics education both in the general curriculum and in the genetics classroom than is currently being given. Most instructors devote <5% of class time to ethical and social issues in their genetics courses. The majority feels that this is inadequate treatment of these topics and most cited lack of time as a major reason they were unable to give more attention to bioethics. We believe biology departments should take the responsibility to ensure that their students are receiving a balanced education. Undergraduate students should be adequately trained in ethics either within their science courses or in a specialized course elsewhere in the curriculum.     

Achievement of genetics in plant reproduction research: the past decade for the coming decade

In the last decade, a variety of innovations of emerging technologies in science have been accomplished. Advanced research environment in plant science has made it possible to obtain whole genome sequence in plant species. But now we recognize this by itself is not sufficient to understand the overall biological significance. Since Gregor Mendel established a principle of genetics, known as Mendel's Laws of Inheritance, genetics plays a prominent role in life science, and this aspect is indispensable even in modern plant biology. In this review, we focus on achievements of genetics on plant sexual reproduction research in the last decade and discuss the role of genetics for the coming decade. It is our hope that this will shed light on the importance of genetics in plant biology and provide valuable information to plant biologists.     

Mendel, the empiricist

In contemporary texts in biology and genetics, Mendel is frequently portrayed as a theorist who was the father of classical genetics. According to some authors, he created his theory of inheritance to explain the results of his experimental hybridizations of peas. Others have proposed that he designed and carried out his experiments to demonstrate the correctness of a theory of inheritance he had already developed. We disagree strongly with these views of Mendel. Instead, we have come to regard him as an empirical investigator trying to discover the empirical natural laws describing the formation of hybrid peas and the development of their offspring over several generations. We have supported our view with an analysis of portions of Mendel's paper and his letters to Carl N ageli.     

人类血型性状综合遗传大实验的设计与教学实践

综合大实验能够训练学生灵活应用理论知识并掌握实验技能,成为当前实验课教学改革的重要方式。本文以人类的ABO血型性状为实验对象,设计了“人类ABO血型分子基因分型与群体遗传平衡分析”大实验。实验中提取同学唾液中黏膜细胞的DNA,经过PCR扩增目的片段、酶切及电泳分离一系列分子遗传技术分析,鉴定出每位同学的基因型;然后以全班同学为一个类似孟德尔群体调查ABO血型的各种基因型频数,用Popgene软件分析各种群体遗传参数。通过开放教学不仅让学生掌握了分子遗传实验技术和群体遗传分析技术及软件应用,还让学生自主设计方案优化分子技术环节,提高学生驾驭知识的能力。通过5年的教学探索与实践,建立了稳定的分子遗传实验体系,能够清楚地检测出ABO血型的6种基因型：I^AI^A、I^Ai、I^BI^B、I^Bi、I^AI^B、ii;综合了分子遗传与群体遗传的实验教学,统计全班同学6种基因型的频数,直接计算3个复等位基因的频率,进而应用软件分析群体遗传各种参数;实现了学生自主设计并完成实验的开放式实验教学;大实验教学获得了学生的好评,取得了很好的教学效果。该大实验可直接应用于生物类专业的遗传学实验教学,其中的教学理念和方法还可推广应用于其他生物学实验教学。     

Research note: Genes on chromosomes: The conversion of Thomas Hunt Morgan

In the first decade of the twentieth century, the foundation for the science of genetics was set. In 1900, the data of Gregor Mendel were rediscovered. By 1915, a community of scientists accepted that there were entities on chromosomes that controlled the development of observable traits. During the intervening period, Thomas Hunt Morgan was one of the major skeptics regarding the chromosomal location of the genes. His acceptance may have been the turning point for the flowering of American genetics. This paper will discuss the reasons for Morgan's recalcitrance, his conversion to belief, and the nature of the scientific evidence that led to his acceptance.     

What are genes “for” or where are traits “from”? What is the question?

For at least a century it has been known that multiple factors play a role in the development of complex traits, and yet the notion that there are genes “for” such traits, which traces back to Mendel, is still widespread. In this paper, we illustrate how the Mendelian model has tacitly encouraged the idea that we can explain complexity by reducing it to enumerable genes. By this approach many genes associated with simple as well as complex traits have been identified. But the genetic architecture of biological traits, or how they are made, remains largely unknown. In essence, this reflects the tension between reductionism as the current “modus operandi” of science, and the emerging knowledge of the nature of complex traits. Recent interest in systems biology as a unifying approach indicates a reawakened acceptance of the complexity of complex traits, though the temptation is to replace “gene for” thinking by comparably reductionistic “network for” concepts. Both approaches implicitly mix concepts of variants and invariants in genetics. Even the basic question is unclear: what does one need to know to “understand” the genetic basis of complex traits? New operational ideas about how to deal with biological complexity are needed.     

Development and evaluation of a genetics literacy assessment instrument for undergraduates

There is continued emphasis on increasing and improving genetics education for grades K-12, for medical professionals, and for the general public. Another critical audience is undergraduate students in introductory biology and genetics courses. To improve the learning of genetics, there is a need to first assess students' understanding of genetics concepts and their level of genetics literacy (i.e., genetics knowledge as it relates to, and affects, their lives). We have developed and evaluated a new instrument to assess the genetics literacy of undergraduate students taking introductory biology or genetics courses. The Genetics Literacy Assessment Instrument is a 31-item multiple-choice test that addresses 17 concepts identified as central to genetics literacy. The items were selected and modified on the basis of reviews by 25 genetics professionals and educators. The instrument underwent additional analysis in student focus groups and pilot testing. It has been evaluated using approximately 400 students in eight introductory nonmajor biology and genetics courses. The content validity, discriminant validity, internal reliability, and stability of the instrument have been considered. This project directly enhances genetics education research by providing a valid and reliable instrument for assessing the genetics literacy of undergraduate students.     

数学原理在遗传学教学中的应用与实践

遗传学在生命科学中具有举足轻重的作用,其建立、发展和完善与数学紧密相连。由于遗传学自身具有较强的理论性和实践性,其内容较为抽象,导致部分学生缺乏学习兴趣。采用"渗透式"教学的方法,把遗传学知识和数学思维有机结合,巧妙应用数学的方法和技巧,将部分遗传现象进行数学抽象和逻辑推理,提升学生对遗传学的认识和理解层次,进一步提高学生的学习和研究能力。     

J. B. S. Haldane,Ernst Mayr and the Beanbag Genetics Dispute

Starting from the early decades of the twentieth century, evolutionary biology began to acquire mathematical overtones. This took place via the development of a set of models in which the Darwinian picture of evolution was shown to be consistent with the laws of heredity discovered by Mendel. The models, which came to be elaborated over the years, define a field of study known as population genetics. Population genetics is generally looked upon as an essential component of modern evolutionary theory. This article deals with a famous dispute between J. B. S. Haldane, one of the founders of population genetics, and Ernst Mayr, a major contributor to the way we understand evolution. The philosophical undercurrents of the dispute remain relevant today. Mayr and Haldane agreed that genetics provided a broad explanatory framework for explaining how evolution took place but differed over the relevance of the mathematical models that sought to underpin that framework. The dispute began with a fundamental issue raised by Mayr in 1959: in terms of understanding evolution, did population genetics contribute anything beyond the obvious? Haldane’s response came just before his death in 1964. It contained a spirited defense, not just of population genetics, but also of the motivations that lie behind mathematical modelling in biology. While the difference of opinion persisted and was not glossed over, the two continued to maintain cordial personal relations.     

Mendel's genes: toward a full molecular characterization

The discipline of classical genetics is founded on the hereditary behavior of the seven genes studied by Gregor Mendel. The advent of molecular techniques has unveiled much about the identity of these genes. To date, four genes have been sequenced: A (flower color), LE (stem length), I (cotyledon color), and R (seed shape). Two of the other three genes, GP (pod color) and FA (fasciation), are amenable to candidate gene approaches on the basis of their function, linkage relationships, and synteny between the pea and Medicago genomes. However, even the gene (locus) identity is not known for certain for the seventh character, the pod form, although it is probably V. While the nature of the mutations used by Mendel cannot be determined with certainty, on the basis of the varieties available in Europe in the 1850s, we can speculate on their nature. It turns out that these mutations are attributable to a range of causes-from simple base substitutions and changes to splice sites to the insertion of a transposon-like element. These findings provide a fascinating connection between Mendelian genetics and molecular biology that can be used very effectively in teaching new generations of geneticists. Mendel's characters also provide novel insights into the nature of the genes responsible for characteristics of agronomic and consumer importance.     

The Mathematical Basis of Mendelian Genetics

In a climate where increasing numbers of students are encouraged to pursue post-secondary education, the level of preparedness students have for college-level coursework is not far from the minds of all educators, especially high school teachers. Specifically within the biological sciences, introductory biology classes often serve as the gatekeeper or a pre-requisite for subsequent coursework in those fields and pre-professional programmes (eg pre-medicine or pre-veterinarian). Thus, how helpful high school science and mathematics experiences are in preparing students for their introductory biology classes is important and relevant for teachers, science educators and policy makers alike. This quantitative study looked at the association between students' high school science and mathematics experiences with introductory college biology performance. Using a nationally representative sample of US students (n?=?2667) enrolled in 33 introductory college biology courses, a multi-level statistical model was developed to analyse the association between high school educational experiences and the final course grade in introductory biology courses. Advanced high school science and mathematics coursework, an emphasis on a deep conceptual understanding of biology concepts and a prior knowledge of concepts addressed in well-structured laboratory investigations are all positively associated with students' achievement in introductory college biology.     

Transposing from the Laboratory to the Classroom to Generate Authentic Research Experiences for Undergraduates

Large lecture classes and standardized laboratory exercises are characteristic of introductory biology courses. Previous research has found that these courses do not adequately convey the process of scientific research and the excitement of discovery. Here we propose a model that provides beginning biology students with an inquiry-based, active learning laboratory experience. The Dynamic Genome course replicates a modern research laboratory focused on eukaryotic transposable elements where beginning undergraduates learn key genetics concepts, experimental design, and molecular biological skills. Here we report on two key features of the course, a didactic module and the capstone original research project. The module is a modified version of a published experiment where students experience how virtual transposable elements from rice (Oryza sativa) are assayed for function in transgenic Arabidopsis thaliana. As part of the module, students analyze the phenotypes and genotypes of transgenic plants to determine the requirements for transposition. After mastering the skills and concepts, students participate in an authentic research project where they use computational analysis and PCR to detect transposable element insertion site polymorphism in a panel of diverse maize strains. As a consequence of their engagement in this course, students report large gains in their ability to understand the nature of research and demonstrate that they can apply that knowledge to independent research projects.     

WinPop 2.5: software for representing population genetics phenomena

The curriculum for genetics courses is shifting from a classical to a more molecular genetics focus, increasing the importance of subjects such as population genetics. Population genetics is a computational and statistical field that requires a good understanding of the nature of stochastic events. It is a difficult field for biology students with a limited mathematical background and there is a need for visualisation tools to facilitate understanding by the use of practical examples. WinPop provides students and researchers with a visual tool to allow the simulation and representation of population genetics phenomena. WinPop is a user-friendly software meant for use in population genetics courses and basic research. WinPop 2.5 contains six different modules that represent and simulate population genetics models. Genotype and allele frequencies are calculated under the different models: panmixia, genetic drift, assortative matings, selection, gene flow and mutation. The program's interface presents information in Cartesian graphics and isosceles triangular coordinate systems, allowing the user to save graphical and textual data output from the simulations. WinPop is developed in Visual Basic 6.0 and uses Windows 95 and higher. WinPop 2.5 can be downloaded from http://www.genedrift.org/winpop.php.     

The Cold War Context of the Golden Jubilee,Or, Why We Think of Mendel as the Father of Genetics

In September 1950, the Genetics Society of America (GSA) dedicated its annual meeting to a "Golden Jubilee of Genetics" that celebrated the 50th anniversary of the rediscovery of Mendel's work. This program, originally intended as a small ceremony attached to the coattails of the American Institute of Biological Sciences (AIBS) meeting, turned into a publicity juggernaut that generated coverage on Mendel and the accomplishments of Western genetics in countless newspapers and radio broadcasts. The Golden Jubilee merits historical attention as both an intriguing instance of scientific commemoration and as an early example of Cold War political theatre. Instead of condemning either Lysenko or Soviet genetics, the Golden Jubilee would celebrate Mendel - and, not coincidentally, the practical achievements in plant and animal breeding his work had made possible. The American geneticists' focus on the achievements of Western genetics as both practical and theoretical, international, and, above all, non-ideological and non-controversial, was fully intended to demonstrate the success of the Western model of science to both the American public and scientists abroad at a key transition point in the Cold War. An implicit part of this article's argument, therefore, is the pervasive impact of the Cold War in unanticipated corners of postwar scientific culture.     

Darwinism after Mendelism: the case of Sewall Wright's intellectual synthesis in his shifting balance theory of evolution (1931)

Historians of science have long been agreeing: what many textbooks of evolutionary biology say, about the histories of Darwinism and the New Synthesis, is just too simple to do justice to the complexities revealed to critical scholarship and historiography. There is no current consensus, however, on what grand narratives should replace those textbook histories. The present paper does not offer to contribute directly to any grand, consensual, narrational goals; but it does seek to do so indirectly by showing how, in just one individual case, details of intellectual biography connect with big picture issues. To this end, I examine here how very diverse scientific and metaphysical commitments were integrated in Sewall Wright's own personal synthesis of biology and philosophy. Taking as the decisive text the short final section of Wright's long 1931 paper on 'Evolution in Mendelian populations,' I examine how his shifting balance theory (SBT) related to his optimum breeding strategy research, his physiological genetics, his general theory of homogenising and heterogenesing causation and his panpsychist view of mind and matter; and I discuss how understanding these relations can clarify Wright's place in the longue durée of evolutionary thought.     

How fieldwork-oriented biology teachers establish formal outdoor education practices

ABSTRACT

Fieldwork is an important part of biology as well as science and biology education. However, teachers perceive several reasons for the limited use of fieldwork in schools. Further, outdoor education is often organised as a single fieldtrip guided by outdoor educators, and little research has been done on fieldwork as a regular part of formal biology education. This case study explores three secondary-school biology teachers who untypically use outdoor education as a major part of their ecology courses for 8^th grade students (median age 14). Berger and Luckmann’s theory of the process of institutionalization as a theoretical background is used to interpret the pedagogical and organizational choices of the case study teachers. Analysis of the interviews of the selected three teachers revealed pedagogical and organizational means through which outdoor teaching is institutionalized into a regular activity in biology lessons. The teachers considered regularity, assessment practices and the school curriculum as major tools to legitimate outdoor learning as a formal schoolwork and foster successful learning. However, they also emphasised students’ freedom during outdoor activities. The findings are discussed in terms of how the teachers succeeded in combining the institutional order of formal schooling with students’ freedom in nature.     

Crossing over...Markov meets Mendel

Chromosomal crossover is a biological mechanism to combine parental traits. It is perhaps the first mechanism ever taught in any introductory biology class. The formulation of crossover, and resulting recombination, came about 100 years after Mendel's famous experiments. To a great extent, this formulation is consistent with the basic genetic findings of Mendel. More importantly, it provides a mathematical insight for his two laws (and corrects them). From a mathematical perspective, and while it retains similarities, genetic recombination guarantees diversity so that we do not rapidly converge to the same being. It is this diversity that made the study of biology possible. In particular, the problem of genetic mapping and linkage-one of the first efforts towards a computational approach to biology-relies heavily on the mathematical foundation of crossover and recombination. Nevertheless, as students we often overlook the mathematics of these phenomena. Emphasizing the mathematical aspect of Mendel's laws through crossover and recombination will prepare the students to make an early realization that biology, in addition to being experimental, IS a computational science. This can serve as a first step towards a broader curricular transformation in teaching biological sciences. I will show that a simple and modern treatment of Mendel's laws using a Markov chain will make this step possible, and it will only require basic college-level probability and calculus. My personal teaching experience confirms that students WANT to know Markov chains because they hear about them from bioinformaticists all the time. This entire exposition is based on three homework problems that I designed for a course in computational biology. A typical reader is, therefore, an instructional staff member or a student in a computational field (e.g., computer science, mathematics, statistics, computational biology, bioinformatics). However, other students may easily follow by omitting the mathematically more elaborate parts. I kept those as separate sections in the exposition.     

Perceptions of nature conservation by future biologists attending private universities in São Paulo State,Brazil

As conservation agents, biologists play a central role in nature preservation as information-gatherers, promoters of environmental education, lobbyists, and members of societies. Consequently, it is important to understand what factors determine their attitudes towards conservation. We aimed to assess which taxa and recovery measures students from biology core courses consider priorities for conservation and to determine the value students associate with conservation compared to other topics. We asked students (n?=?122) from two private universities in São Paulo State, Brazil to fill out an anonymous questionnaire. They highlighted rarity, vanishing habitats and endemism as important criteria in prioritizing species. Carnivores were identified as the most threatened mammals and habitat recovery was deemed to be the most efficient conservation action. Students valued healthcare, cultural heritage and science over conservation. Our results reveal a two-sided perspective of conservation among students from biology core courses; they possess knowledge of conservation issues but are greatly influenced by anthropocentric and utilitarian views of nature.