The early history of genetics can be divided into two stages. The first stage lasted from about 1900 to 1909, and the second stage began in 1910. The first phase, often called the Mendelian period, focused on controversies over evolution and the question of whether Mendelian inheritance was universally valid. The main representatives of this period (stage) are DeVry, Bateson and Johnson, who are often called "early Mendelists." Different people have different understandings of the term "Mendelism". Depends on which aspect of Mendelism he wants to emphasize. For those who established genetics, it refers to a period when granular inheritance was firmly established and focused on hard inheritance. For evolutionists, "Mendelism" refers to a period in which certain prominent geneticists spread completely erroneous views about evolutionary problems and speciation. Mutation pressure was thought to be far more important than natural selection, and these views were alien to naturalists. Thus, the same word "Mendelism" is sometimes used to express approval or support and sometimes in a derogatory sense.
The second stage began in 1910, and was mainly represented by the Morgan school; it mainly focused on the study of purely genetic issues, such as the nature of genes, the arrangement of genes on chromosomes, etc. The term "genetics", suggested by Bateson in 1906, has since become generally accepted as the broad concept of the science that studies hereditary phenomena.
Although it took 34 years for Mendel's article to be rediscovered, once it was rediscovered it was widely disseminated at an unprecedented speed. Neither Currens nor Chuchemak had seen DeVry's article in April 1900. And published their own relevant articles in May and June respectively. Bateson reported Mendel's experiments at the meeting of the Royal Horticultural Society in England on May 8, and Mendel's work was soon introduced in Cuenot, France.
Like many important scientific activities, the momentum of subsequent progress also varies in different countries. There is no doubt that Britain was far ahead in the progress of Mendelian genetics, but it was soon caught up and finally surpassed by the United States (representatives of the United States are Castle, East, Morgan and other scholars). German genetics still inherits the tradition of the 1880s, focusing on developmental genetics and some uncommon genetic phenomena (real or apparent cytoplasmic inheritance, protozoan inheritance, etc.). In France, Cuenot made little progress until the 1930s after a good start. In the Soviet Union, as Gaissinovich (1971) pointed out, "only during the Soviet period did genetics develop as a science". In northwestern Europe, the science of genetics was not born. Where genetics thrives and in which direction it develops depends entirely on who leads the field. Curiously, however, neither Currens nor DeVry played an important role in the subsequent development of Mendelian genetics. This credit, at least in the early days, must be attributed to Bateson (1861-1926), who appreciated the significance of Mendelian genetics far more than the so-called rediscoverers.
Bateson has been studying at Hopkins University since W. K． During his stay in Professor Brooks's laboratory (1883-1884), he was very interested in discontinuous variation (see Part 2) and conducted breeding experiments from the 1980s, but he really concentrated on research in this area around 1897. . On July 11, 1899, he read a paper entitled "Hybridization and Cross-breeding as a Method of Scientific Research" to the Royal Horticultural Society. It can be seen from this paper that he had not yet proposed the theory of genetics at that time, although there were many experimental results that were easily explained according to Mendel's point of view. It was not until May 8, 1900 that he was deeply inspired after reading Mendel's original work on the train from Cambridge to London. He soon became an ardent Mendelian and translated Mende's article and published it with footnotes in the Journal of the Royal Horticultural Society (1900). Part of Bateson's enthusiasm stemmed from his belief that Mendel's theory of segregation was an affirmation of his (erroneous) thesis that speciation was the result of discontinuous variation. DeVry also proposed a similar evolutionary theory and also believed that the discontinuity of Mendelian genetic factors was important evidence for his theory of sudden mutation of species. Therefore, the reason why Mendel's theory has attracted widespread attention is because of the correct (if not incorrect) understanding. The criticisms caused by Bateson and DeVry's arguments have been introduced in Chapter 12. In the following I will only discuss Bateson's contribution to transmission genetics.
Most important terms in genetics were proposed by Bateson. He coined the new word "genetics" for this new discipline, and in 1901 he first coined the terms "allele" (originally allelomorPh, later simplified), "homozygote" and "heterozygote". With these semantically clear terms, academic exchanges during this period were greatly facilitated. Of course, Bateson and his colleagues also made substantial contributions to our understanding of genetic phenomena. They first discovered situations that were inconsistent with simple phenomena observed by Mendel (such as incomplete linkage of multiple genes).
It was through Bateson that genetics gained a momentum or impetus in England that it had absolutely no other country in Europe.
Bateson was a complex figure, combative and almost abrasive in debates, but at the same time completely dedicated to his cause. He was a strange mixture of conservatism and revolution. He was a major activist in genetics during the first decade after 1900, and Caslle (1951) actually made a lot of sense when he said that Bateson "was the real founder of genetics." However, in 1910 From now on, his opposition to the chromosome theory and his continued insistence on the sudden formation of species can no longer be said to be constructive. As a revolutionary, he once left an immortal saying (1908: 22): "Cherish the exceptions you find; if there are no exceptions, the work will become so boring that no one will be willing to push it further. . Keep these exceptions in plain view. The exceptions are like the rough stones of a building under construction, telling people how to further process and indicating where the next part should be placed." In his own research, He paid great attention to actual exceptions or apparent exceptions, and some of his important discoveries were the result of following this motto.