Genetics with Fundamentals of Breeding - M.P. Myhun - 2008

CHAPTER I. Genetics as a Science

1.2. Stages in the Development of Genetics

Humanity's attempt to understand the phenomena of heredity and Variability dates back to time immemorial. Throughout its existence and development, mankind has sought to understand and unravel the mysteries surrounding

the birth and development of living organisms. It took a vast amount of time and research before human thought grasped the true regularities of inheritance. The foundations of this science were laid in 1865 by G. Mendel in his seminal work "Experiments on Plant Hybrids". However, his contemporaries failed to appreciate Mendel's research for 35 years. It was not until 1900 that Hugo de Vries (Netherlands), Carl Correns (Germany), and Erich Tschermak (Austria), simultaneously and independently of one another, rediscovered the fundamental laws of inheritance. Therefore, 1900 is considered the birth year of genetics. It subsequently became clear that the patterns established by G. Mendel are universal in nature, applying to both animal and plant organisms. Over the course of a century, genetics took shape as an independent biological science and gained widespread recognition. Modern scientists divide the Selection/4.html">Development of Genetics into three stages.

The First stage (1900–1930) is the era of classical genetics, associated with the ESTABLISHMENT OF THE discrete theory of heredity (Mendelism). W. Bateson coined the term "genetics" in 1906. W. Johannsen introduced The concepts of "Gene", "genotype", and "phenotype" into genetics between 1903 and 1909. This period also saw the discovery of linked inheritance and the chromosome theory of heredity by T.H. Morgan (1911) and others.

The Second Stage (1930–1953) was marked by The Development of experimental mutagenesis; it was proven that the gene is a discrete system; the principles of population and evolutionary genetics were substantiated; biochemical genetics emerged; Evidence of the genetic role of DNA was obtained; and the regularities of nucleotide composition were elucidated.

The Third Stage in the development of genetics began in 1953 (the period of Molecular Genetics) following the elucidation of the Structural Organization of the DNA molecule by J. Watson and F. Crick. This marks an era of intensive development in molecular genetics that continues to this day. Introduction/32.html">Genetic Engineering approaches have provided a new level of advancement, enabling the manipulation of individual genes, the artificial creation of novel gene combinations, The transfer of genes from one Organism into the Cells of another, and much more.