Gregor Johann Mendel was a scientist, Augustinian friar and abbot of St. Thomas' Abbey in Brno, Margraviate of Moravia. Mendel was born in a German-speaking family in the Silesian part of the Austrian Empire and gained posthumous recognition as the founder of the modern science of genetics. Though farmers had known for millennia that crossbreeding of animals and plants could favor certain desirable traits, Mendel's pea plant experiments conducted between 1856 and 1863 established many of the rules of heredity, now referred to as the laws of Mendelian inheritance. Mendel worked with seven characteristics of pea plants: plant height, pod shape and color, seed shape and color, flower position and color. Taking seed color as an example, Mendel showed that when a true-breeding yellow pea and a true-breeding green pea were cross-bred their offspring always produced yellow seeds. However, in the next generation, the green peas reappeared at a ratio of 1 green to 3 yellow. To explain this phenomenon, Mendel coined the terms “recessive” and “dominant” in reference to certain traits.
He published his work in 1866, demonstrating the actions of invisible “factors”—now called genes—in predictably determining the traits of an organism. The profound significance of Mendel's work was not recognized until the turn of the 20th century with the rediscovery of his laws. Erich von Tschermak, Hugo de Vries, Carl Correns and William Jasper Spillman independently verified several of Mendel's experimental findings, ushering in the modern age of genetics. Mendel was born into a German-speaking family in Hynčice, at the Moravian-Silesian border, Austrian Empire, he was the son of Anton and Rosine Mendel and had one older sister and one younger, Theresia. They lived and worked on a farm, owned by the Mendel family for at least 130 years. During his childhood, Mendel worked as a gardener and studied beekeeping; as a young man, he attended gymnasium in Opava. He had to take four months off during his gymnasium studies due to illness. From 1840 to 1843, he studied practical and theoretical philosophy and physics at the Philosophical Institute of the University of Olomouc, taking another year off because of illness.
He struggled financially to pay for his studies, Theresia gave him her dowry. He helped support her three sons, two of whom became doctors, he became a friar in part because it enabled him to obtain an education without having to pay for it himself. As the son of a struggling farmer, the monastic life, in his words, spared him the "perpetual anxiety about a means of livelihood." He was given the name Gregor. When Mendel entered the Faculty of Philosophy, the Department of Natural History and Agriculture was headed by Johann Karl Nestler who conducted extensive research of hereditary traits of plants and animals sheep. Upon recommendation of his physics teacher Friedrich Franz, Mendel entered the Augustinian St Thomas's Abbey in Brno and began his training as a priest. Born Johann Mendel, he took the name Gregor upon entering religious life. Mendel worked as a substitute high school teacher. In 1850, he failed the oral part, the last of three parts, of his exams to become a certified high school teacher.
In 1851, he was sent to the University of Vienna to study under the sponsorship of Abbot C. F. Napp so that he could get more formal education. At Vienna, his professor of physics was Christian Doppler. Mendel returned to his abbey in 1853 as a teacher, principally of physics. In 1856, he again failed the oral part. In 1867, he replaced Napp as abbot of the monastery. After he was elevated as abbot in 1868, his scientific work ended, as Mendel became overburdened with administrative responsibilities a dispute with the civil government over its attempt to impose special taxes on religious institutions. Mendel died on 6 January 1884, at the age of 61, in Brno, Austria-Hungary, from chronic nephritis. Czech composer Leoš Janáček played the organ at his funeral. After his death, the succeeding abbot burned all papers in Mendel's collection, to mark an end to the disputes over taxation. Gregor Mendel, known as the "father of modern genetics", was inspired by both his professors at the Palacký University and his colleagues at the monastery to study variation in plants.
In 1854, Napp authorized Mendel to carry out a study in the monastery's 2 hectares experimental garden, planted by Napp in 1830. Unlike Nestler, who studied hereditary traits in sheep, Mendel used the common edible pea and started his experiments in 1856. After initial experiments with pea plants, Mendel settled on studying seven traits that seemed to be inherited independently of other traits: seed shape, flower color, seed coat tint, pod shape, unripe pod color, flower location, plant height, he first focused on seed shape, either angular or round. Between 1856 and 1863 Mendel cultivated and tested some 28,000 plants, the majority of which were pea plants; this study showed that, when true-breeding different varieties were crossed to each other, in the second generation, one in four pea pl
Societas eruditorum incognitorum in terris Austriacis
Societas eruditorum incognitorum in terris Austriacis was the first learned society in the lands under control of Austrian Habsburgs. It was established, formally, in 1746 at the university and episcopal town of Olomouc in order to spread Enlightenment ideas, its monthly journal, "Monatliche Auszüge" was the first scientific journal in the Habsburg Monarchy. When the Habsburgs took over the Czech throne in 1526, as many as nine out of ten inhabitants of the crown lands were Protestants. Olomouc, as the episcopal seat became a centre for the counter-reformation, with the Jesuits taking over the local college in 1566. In 1573 the college was promoted to University status, the special papal seminary, the Collegium Nordicum was established in 1578. Competing with the schools run by the Hussite "Bohemian Brethren", the Jesuits obtained an effective monopoly after the Thirty year's war: this brought savage re-Catholicization and Germanization to the Czech population; the Jesuit monopoly was however challenged because the Moravian nobility wanted to expand the range of areas taught beyond just theology and philosophy.
In 1679 secular legal studies were introduced at the University, in 1725 the Academy of Nobility was established in Olomouc. Both these developments met with fierce opposition from the Jesuits, it was the strong Jesuit reaction which led an alumnus of Faculty of Philosophy of Olomouc University, Joseph von Petrasch, to join with another locally based aristocrat, Francesco G. Giannini in obtaining the consent of empress Maria Theresa for the establishment of a learned society in 1746. Von Petrasch was a noble of Slavonian origin who at one stage had studied Law at Leiden and who had pursued a career as an adjutant to Prince Eugene of Savoy which had left him with the financial means to support the Societas eruditorum from his private wealth; the society set itself the goals of advancing the sciences, in particular the natural sciences, mathematics and the history of scientific research, along with philology and literature. In the religious conflicts of the time between Protestants and Catholics, the Societas eruditorum took an objective and pragmatic approach, it had members in both camps.
Petrasch was able to recruit many members from across Central Europe, eager to spread Enlightenment ideas with a journal of their own. The members included local members of the nobility, state officials, Benedictine ecclesiastical historians, its so-called "corresponding members" included the north German dramatist and German language reformer Johann Christoph Gottsched, the Slovak founder of Hungarian history-writing Matthias Bel, leading Italian scholars Ludovico Antonio Muratori and Angelo Maria Quirini and the Czech Bonaventura Piter as well as the Archbishop of Kraków Andrzej Stanisław Załuski and the Cardinal Domenico Silvio Passionei. The members were designated as "anonymous"; the society published the first scientific journal in the Habsburg Monarchy, the Olmützer Monathlichen Auszüge Alt- und neuer Gelehrter Sachen, with each issue having some 80 pages. The journal was on sale in Olomouc, Prague, Vienna, as well as by book sellers in Nuremberg, Wrocław, Leipzig or Bautzen, it was concerned with the reform and promotion of the German language as well as with spreading the Enlightenment ideas.
The society was propagating various streams of contemporary thought. Two of them were of particular importance: the philosophical rationalism of Christian Wolff, a practical approach to philosophy which in Moravia was combined with the Catholic reformism of Ludovico Antonio Muratori; the German focus of the Society was not so much aimed against Czech language, rather against the prevailing use of Latin as lingua franca as well as against the gallomania of the high German society. The Society received state protection, but opposition from within the Jesuit-dominated town, ongoing problems with Vienna-based censors, as well as disagreements from within the Society itself, led to its premature demise, its periodical represented a landmark: the first attempt within the Habsburg monarchy to unite the learned, the dilettanti and the curieux and to bring them into contact with the pan-European Respublica literaria. Josef Vratislav Monse
An academic or scholarly journal is a periodical publication in which scholarship relating to a particular academic discipline is published. Academic journals serve as permanent and transparent forums for the presentation and discussion of research, they are peer-reviewed or refereed. Content takes the form of articles presenting original research, review articles, book reviews; the purpose of an academic journal, according to Henry Oldenburg, is to give researchers a venue to "impart their knowledge to one another, contribute what they can to the Grand design of improving natural knowledge, perfecting all Philosophical Arts, Sciences."The term academic journal applies to scholarly publications in all fields. Scientific journals and journals of the quantitative social sciences vary in form and function from journals of the humanities and qualitative social sciences; the first academic journal was Journal des sçavans, followed soon after by Philosophical Transactions of the Royal Society, Mémoires de l'Académie des Sciences.
The first peer-reviewed journal was Medical Essays and Observations. The idea of a published journal with the purpose of " people know what is happening in the Republic of Letters" was first conceived by Eudes de Mazerai in 1663. A publication titled Journal littéraire général was supposed to be published to fulfill that goal, but never was. Humanist scholar Denis de Sallo and printer Jean Cusson took Mazerai's idea, obtained a royal privilege from King Louis XIV on 8 August 1664 to establish the Journal des sçavans; the journal's first issue was published on 5 January 1665. It was aimed at people of letters, had four main objectives: review newly published major European books, publish the obituaries of famous people, report on discoveries in arts and science, report on the proceedings and censures of both secular and ecclesiastical courts, as well as those of Universities both in France and outside. Soon after, the Royal Society established Philosophical Transactions of the Royal Society in March 1665, the Académie des Sciences established the Mémoires de l'Académie des Sciences in 1666, which more focused on scientific communications.
By the end of the 18th century, nearly 500 such periodical had been published, the vast majority coming from Germany and England. Several of those publications however, in particular the German journals, tended to be short lived. A. J. Meadows has estimated the proliferation of journal to reach 10,000 journals in 1950, 71,000 in 1987. However, Michael Mabe warns that the estimates will vary depending on the definition of what counts as a scholarly publication, but that the growth rate has been "remarkably consistent over time", with an average rates of 3.46% per year from 1800 to 2003. In 1733, Medical Essays and Observations was established by the Medical Society of Edinburgh as the first peer-reviewed journal. Peer review was introduced as an attempt to increase the pertinence of submissions. Other important events in the history of academic journals include the establishment of Nature and Science, the establishment of Postmodern Culture in 1990 as the first online-only journal, the foundation of arXiv in 1991 for the dissemination of preprints to be discussed prior to publication in a journal, the establishment of PLOS One in 2006 as the first megajournal.
There are two kinds of article or paper submissions in academia: solicited, where an individual has been invited to submit work either through direct contact or through a general submissions call, unsolicited, where an individual submits a work for potential publication without directly being asked to do so. Upon receipt of a submitted article, editors at the journal determine whether to reject the submission outright or begin the process of peer review. In the latter case, the submission becomes subject to review by outside scholars of the editor's choosing who remain anonymous; the number of these peer reviewers varies according to each journal's editorial practice – no fewer than two, though sometimes three or more, experts in the subject matter of the article produce reports upon the content and other factors, which inform the editors' publication decisions. Though these reports are confidential, some journals and publishers practice public peer review; the editors either choose to reject the article, ask for a revision and resubmission, or accept the article for publication.
Accepted articles are subjected to further editing by journal editorial staff before they appear in print. The peer review can take from several weeks to several months. Review articles called "reviews of progress," are checks on the research published in journals; some journals are devoted to review articles, some contain a few in each issue, others do not publish review articles. Such reviews cover the research from the preceding year, some for longer or shorter terms; some journals are enumerative. Yet others are evaluative; some journals are published in series, each covering a complete subject field year, or covering specific fields through several years. Unlike original research article
Biology is the natural science that studies life and living organisms, including their physical structure, chemical processes, molecular interactions, physiological mechanisms and evolution. Despite the complexity of the science, there are certain unifying concepts that consolidate it into a single, coherent field. Biology recognizes the cell as the basic unit of life, genes as the basic unit of heredity, evolution as the engine that propels the creation and extinction of species. Living organisms are open systems that survive by transforming energy and decreasing their local entropy to maintain a stable and vital condition defined as homeostasis. Sub-disciplines of biology are defined by the research methods employed and the kind of system studied: theoretical biology uses mathematical methods to formulate quantitative models while experimental biology performs empirical experiments to test the validity of proposed theories and understand the mechanisms underlying life and how it appeared and evolved from non-living matter about 4 billion years ago through a gradual increase in the complexity of the system.
See branches of biology. The term biology is derived from the Greek word βίος, bios, "life" and the suffix -λογία, -logia, "study of." The Latin-language form of the term first appeared in 1736 when Swedish scientist Carl Linnaeus used biologi in his Bibliotheca botanica. It was used again in 1766 in a work entitled Philosophiae naturalis sive physicae: tomus III, continens geologian, phytologian generalis, by Michael Christoph Hanov, a disciple of Christian Wolff; the first German use, was in a 1771 translation of Linnaeus' work. In 1797, Theodor Georg August Roose used the term in the preface of a book, Grundzüge der Lehre van der Lebenskraft. Karl Friedrich Burdach used the term in 1800 in a more restricted sense of the study of human beings from a morphological and psychological perspective; the term came into its modern usage with the six-volume treatise Biologie, oder Philosophie der lebenden Natur by Gottfried Reinhold Treviranus, who announced: The objects of our research will be the different forms and manifestations of life, the conditions and laws under which these phenomena occur, the causes through which they have been effected.
The science that concerns itself with these objects we will indicate by the name biology or the doctrine of life. Although modern biology is a recent development, sciences related to and included within it have been studied since ancient times. Natural philosophy was studied as early as the ancient civilizations of Mesopotamia, the Indian subcontinent, China. However, the origins of modern biology and its approach to the study of nature are most traced back to ancient Greece. While the formal study of medicine dates back to Hippocrates, it was Aristotle who contributed most extensively to the development of biology. Important are his History of Animals and other works where he showed naturalist leanings, more empirical works that focused on biological causation and the diversity of life. Aristotle's successor at the Lyceum, wrote a series of books on botany that survived as the most important contribution of antiquity to the plant sciences into the Middle Ages. Scholars of the medieval Islamic world who wrote on biology included al-Jahiz, Al-Dīnawarī, who wrote on botany, Rhazes who wrote on anatomy and physiology.
Medicine was well studied by Islamic scholars working in Greek philosopher traditions, while natural history drew on Aristotelian thought in upholding a fixed hierarchy of life. Biology began to develop and grow with Anton van Leeuwenhoek's dramatic improvement of the microscope, it was that scholars discovered spermatozoa, bacteria and the diversity of microscopic life. Investigations by Jan Swammerdam led to new interest in entomology and helped to develop the basic techniques of microscopic dissection and staining. Advances in microscopy had a profound impact on biological thinking. In the early 19th century, a number of biologists pointed to the central importance of the cell. In 1838, Schleiden and Schwann began promoting the now universal ideas that the basic unit of organisms is the cell and that individual cells have all the characteristics of life, although they opposed the idea that all cells come from the division of other cells. Thanks to the work of Robert Remak and Rudolf Virchow, however, by the 1860s most biologists accepted all three tenets of what came to be known as cell theory.
Meanwhile and classification became the focus of natural historians. Carl Linnaeus published a basic taxonomy for the natural world in 1735, in the 1750s introduced scientific names for all his species. Georges-Louis Leclerc, Comte de Buffon, treated species as artificial categories and living forms as malleable—even suggesting the possibility of common descent. Although he was opposed to evolution, Buffon is a key figure in the history of evolutionary thought. Serious evolutionary thinking originated with the works of Jean-Baptiste Lamarck, the first to present a coherent theory of evolution, he posited that evolution was the result of environmental stress on properties of animals, meaning that the more and rigorously an organ was used, the more complex and efficient it would become, thus adapting the animal to its environment. Lamarck believed that these acquired traits could be passed on to the animal's offspring, who would
Brno is the second largest city in the Czech Republic by population and area, the largest Moravian city, the historical capital city of the Margraviate of Moravia. Brno is the administrative center of the South Moravian Region in which it forms a separate district; the city has about 400,000 inhabitants. Brno is the seat of judicial authority of the Czech Republic – it is the seat of the Constitutional Court, the Supreme Court, the Supreme Administrative Court, the Supreme Public Prosecutor's Office; the city is a significant administrative centre. It is the seat of a number of state authorities, including the Ombudsman, the Office for the Protection of Competition. Brno is an important centre of higher education, with 33 faculties belonging to 13 institutes of higher learning and about 89,000 students. Brno Exhibition Centre ranks among the largest exhibition centres in Europe; the complex opened in 1928 and established the tradition of large exhibitions and trade fairs held in Brno. Brno hosts motorbike and other races on the Masaryk Circuit, a tradition established in 1930, in which the Road Racing World Championship Grand Prix is one of the most prestigious races.
Another cultural tradition is an international fireworks competition, Ignis Brunensis, that attracts tens of thousands of daily visitors. The most visited sights of the city include the Špilberk castle and fortress and the Cathedral of Saints Peter and Paul on Petrov hill, two medieval buildings that dominate the cityscape and are depicted as its traditional symbols; the other large preserved castle near the city is Veveří Castle by Brno Reservoir. This castle is the site of a number of legends. Another architectural monument of Brno is the functionalist Villa Tugendhat, included on the UNESCO list of World Heritage Sites. One of the natural sights nearby is the Moravian Karst; the city is a member of the UNESCO Creative Cities Network and has been designated as a "City of Music" in 2017. The etymology of the name Brno is disputed, it might be derived from the Old Czech brnie'muddy, swampy.' Alternative derivations are from a Slavic verb brniti or a Celtic language spoken in the area before it was overrun by Germanic peoples and Slavic peoples.
Throughout its history, Brno's locals referred to the town in other languages, including Brünn in German, ברין in Yiddish and Bruna in Latin. The city was referred to as Brunn in English, but this usage is not common today; the Asteroid 2889 Brno was named after the city, as well as the Bren light machine gun, one of the most famous weapons of World War II. The Brno basin has been inhabited since prehistoric times, but the town's direct predecessor was a fortified settlement of the Great Moravia Empire known as Staré Zámky, inhabited from the Neolithic Age to the early 11th century. In the early 11th century Brno was established as a castle of a non-ruling prince from the House of Přemyslid, Brno became one of the centres of Moravia along with Olomouc and Znojmo. Brno was first mentioned in Cosmas' Chronica Boëmorum dated to year 1091, when Bohemian king Vratislav II besieged his brother Conrad at Brno castle. In the mid 11th century, Moravia was divided into three separate territories. Seats of these rulers and thus "capitals" of these territories were castles and towns of Brno and Znojmo.
In the late 12th century, Moravia began forming the Margraviate of Moravia. Since until the mid of the 17th century, it was not clear which town should be the capital of Moravia. Political power was therefore "evenly" divided between Brno and Olomouc, but Znojmo played an important role; the Moravian Diet, the Moravian Land Tables, the Moravian Land Court were all seated in both cities at once. However, Brno was the official seat of the Moravian Margraves, its geographical position closer to Vienna became important. Otherwise, until 1642 Olomouc was larger than Brno by population, it was the seat of the only Roman Catholic diocese in Moravia. In 1243 Brno was granted the large and small city privileges by the King, thus it was recognized as a royal city. In 1324 Queen Elisabeth Richeza of Poland founded the current Basilica of the Assumption of Our Lady, now her final resting place. In the 14th century, Brno became one of the centres for the Moravian regional assemblies, whose meetings alternated between Brno and Olomouc.
These assemblies made political and financial decisions. Brno and Olomouc were the seats of the Land Court and the Land Tables, thus they were the two most important cities in Moravia. From the mid 14th century to the early 15th century the Špilberk Castle had served as the permanent seat of the Margraves of Moravia. In the 15th century Brno was besieged in 1428 and again in 1430 by the Hussites during the Hussite Wars. Both attempts to conquer the city failed. In 1641, in the midst of the Thirty Years' War, the Holy Roman Emperor and Margrave of Moravia Ferdinand III commanded permanent relocation of the diet and the land
In academic publishing, a scientific journal is a periodical publication intended to further the progress of science by reporting new research. Articles in scientific journals are written by active scientists such as students and professors instead of professional journalists. There are thousands of scientific journals in publication, many more have been published at various points in the past. Most journals are specialized, although some of the oldest journals such as Nature publish articles and scientific papers across a wide range of scientific fields. Scientific journals contain articles that have been peer reviewed, in an attempt to ensure that articles meet the journal's standards of quality, scientific validity. Although scientific journals are superficially similar to professional magazines, they are quite different. Issues of a scientific journal are read casually, as one would read a magazine; the publication of the results of research is an essential part of the scientific method. If they are describing experiments or calculations, they must supply enough details that an independent researcher could repeat the experiment or calculation to verify the results.
Each such journal article becomes part of the permanent scientific record. Articles in scientific journals can be used in higher education. Scientific articles allow researchers to keep up to date with the developments of their field and direct their own research. An essential part of a scientific article is citation of earlier work; the impact of articles and journals is assessed by counting citations. Some classes are devoted to the explication of classic articles, seminar classes can consist of the presentation by each student of a classic or current paper. Schoolbooks and textbooks have been written only on established topics, while the latest research and more obscure topics are only accessible through scientific articles. In a scientific research group or academic department it is usual for the content of current scientific journals to be discussed in journal clubs. Public funding bodies require the results to be published in scientific journals. Academic credentials for promotion into academic ranks are established in large part by the number and impact of scientific articles published.
Many doctoral programs allow for thesis by publication, where the candidate is required to publish a certain number of scientific articles. Articles tend to be technical, representing the latest theoretical research and experimental results in the field of science covered by the journal, they are incomprehensible to anyone except for researchers in the field and advanced students. In some subjects this is inevitable given the nature of the content. Rigorous rules of scientific writing are enforced by the editors. Articles are either original articles reporting new results or reviews of current literature. There are scientific publications that bridge the gap between articles and books by publishing thematic volumes of chapters from different authors. Many journals have a regional focus, specializing in publishing papers from a particular geographic region, like African Invertebrates; the history of scientific journals dates from 1665, when the French Journal des sçavans and the English Philosophical Transactions of the Royal Society first began systematically publishing research results.
Over a thousand ephemeral, were founded in the 18th century, the number has increased after that. Prior to mid-20th century, peer review was not always necessary, but it became compulsory; the authors of scientific articles are active researchers instead of journalists. As such, the authors receive no compensation from the journal. However, their funding bodies may require them to publish in scientific journals; the paper is submitted to the journal office, where the editor considers the paper for appropriateness, potential scientific impact and novelty. If the journal's editor considers the paper appropriate, the paper is submitted to scholarly peer review. Depending on the field and paper, the paper is sent to 1–3 reviewers for evaluation before they can be granted permission to publish. Reviewers are expected to check the paper for soundness of its scientific argument, i.e. if the data collected or considered in the paper support the conclusion offered. Novelty is key: existing work must be appropriately considered and referenced, new results improving on the state of the art presented.
Reviewers are unpaid and not a part of the journal staff—instead, they should be "peers", i.e. researchers in the same field as the paper in question. The standards that a journal uses to determine publication can vary widely; some journals, such as Nature, Science, PNAS, Physical Review Letters, have a reputation of publishing articles that mark a fundamental breakthrough in their respective fields. In many fields, a formal or informal hierarchy of scientific journals exists. In some countries, journal rankings can be utilized for funding decisions and evaluation of individual researchers, although they are poorly suited for that purpose. For scientific journals Reproducibility and Replicability are core concepts that allow other scientists to check and reproduce the results under the same conditions described
Mendelian inheritance is a type of biological inheritance that follows the laws proposed by Gregor Mendel in 1865 and 1866 and re-discovered in 1900. These laws were controversial; when Mendel's theories were integrated with the Boveri–Sutton chromosome theory of inheritance by Thomas Hunt Morgan in 1915, they became the core of classical genetics. Ronald Fisher combined these ideas with the theory of natural selection in his 1930 book The Genetical Theory of Natural Selection, putting evolution onto a mathematical footing and forming the basis for population genetics within the modern evolutionary synthesis; the principles of Mendelian inheritance were named for and first derived by Gregor Johann Mendel, a nineteenth-century Moravian monk who formulated his ideas after conducting simple hybridisation experiments with pea plants he had planted in the garden of his monastery. Between 1856 and 1863, Mendel tested some 5,000 pea plants. From these experiments, he induced two generalizations which became known as Mendel's Principles of Heredity or Mendelian inheritance.
He described these principles in a two-part paper, Versuche über Pflanzen-Hybriden, that he read to the Natural History Society of Brno on 8 February and 8 March 1865, and, published in 1866. Mendel's conclusions were ignored by the vast majority. Although they were not unknown to biologists of the time, they were not seen as applicable by Mendel himself, who thought they only applied to certain categories of species or traits. A major block to understanding their significance was the importance attached by 19th-century biologists to the apparent blending of many inherited traits in the overall appearance of the progeny, now known to be due to multi-gene interactions, in contrast to the organ-specific binary characters studied by Mendel. In 1900, his work was "re-discovered" by three European scientists, Hugo de Vries, Carl Correns, Erich von Tschermak; the exact nature of the "re-discovery" has been debated: De Vries published first on the subject, mentioning Mendel in a footnote, while Correns pointed out Mendel's priority after having read De Vries' paper and realizing that he himself did not have priority.
De Vries may not have acknowledged truthfully how much of his knowledge of the laws came from his own work and how much came only after reading Mendel's paper. Scholars have accused Von Tschermak of not understanding the results at all. Regardless, the "re-discovery" made Mendelism an controversial theory, its most vigorous promoter in Europe was William Bateson, who coined the terms "genetics" and "allele" to describe many of its tenets. The model of heredity was contested by other biologists because it implied that heredity was discontinuous, in opposition to the continuous variation observable for many traits. Many biologists dismissed the theory because they were not sure it would apply to all species; however work by biologists and statisticians such as Ronald Fisher showed that if multiple Mendelian factors were involved in the expression of an individual trait, they could produce the diverse results observed, thus showed that Mendelian genetics is compatible with natural selection. Thomas Hunt Morgan and his assistants integrated Mendel's theoretical model with the chromosome theory of inheritance, in which the chromosomes of cells were thought to hold the actual hereditary material, created what is now known as classical genetics, a successful foundation which cemented Mendel's place in history.
Mendel's findings allowed scientists such as Fisher and J. B. S. Haldane to predict the expression of traits on the basis of mathematical probabilities. An important aspect of Mendel's success can be traced to his decision to start his crosses only with plants he demonstrated were true-breeding, he only measured discrete characteristics, such as color and position of the seeds, rather than quantitatively variable characteristics. He expressed his results numerically and subjected them to statistical analysis, his method of data analysis and his large sample size gave credibility to his data. He had the foresight to follow several successive generations of pea plants and record their variations, he performed "test crosses" to reveal the presence and proportions of recessive characters. Mendel discovered that, when he crossed purebred white flower and purple flower pea plants, the result was not a blend. Rather than being a mix of the two, the offspring was purple-flowered; when Mendel self-fertilized the F1 generation pea plants, he obtained a purple flower to white flower ratio in the F2 generation of 3 to 1.
The results of this cross are tabulated in the Punnett square to the right. He conceived the idea of heredity units, which he called "factors". Mendel found that there are alternative forms of factors—now called genes—that account for variations in inherited characteristics. For example, the gene for flower color in pea plants exists in two forms, one for purple and the other for white; the alternative "forms" are now called alleles. For each biological trait, an organism inherits one from each parent; these alleles may be the different. An organism that has two identical alleles for a gene is said to be homozygous for that gene. An organism that has two different alleles for a gene is said be heterozygous for that gene. Mendel hypothesized that allele pairs separate randomly, or segregate, from each other during the product