- Created by: BHASKARGOUDA
- Created on: 23-12-16 14:18
1865: Austrian monk Gregor Mendel's paper, Experiments on Plant Hybridization
1868: Mendel studied the inheritance of traits between generations based on experiments involving garden pea plants. He deduced that there is a certain tangible essence that is passed on between generations from both parents. Mendel established the basic principles of inheritance, namely, the principles of dominance, independent assortment, and segregation.
1869: Friedrich Miescher discovers a weak acid in the nuclei of white blood cells that today we call DNA. In 1871 he isolated cell nuclei, separated the nucleic cells from bandages and then treated them with pepsin (an enzyme which breaks down proteins). From this, he recovered an acidic substance which he called "nuclein.''
1880 - 1890: Walther Flemming, Eduard Strasburger, and Edouard Van Beneden elucidate chromosome distribution during cell division
1889: Richard Altmann purified protein free DNA. However, the nucleic acid was not as pure as he had assumed. It was determined later to contain a large amount of protein.
1889: Hugo de Vries postulates that "inheritance of specific traits in organisms comes in particles", naming such particles "(pan)genes"
1902: Archibald Garrod discovered inborn errors of metabolism. An explanation for epistasis is an important manifestation of Garrod’s research, albeit indirectly. When Garrod studied alkaptonuria, a disorder that makes urine quickly turn black due to the presence of gentesate, he noticed that it was prevalent among populations whose parents were closely related.
1903: Walter Sutton and Theodor Boveri independently hypothesizes that chromosomes, which segregate in a Mendelian fashion, are hereditary units; see the chromosome theory. Boveri was studying sea urchins when he found that all the chromosomes in the sea urchins had to be present for proper embryonic development to take place. Sutton's work with grasshoppers showed that chromosomes occur in matched pairs of maternal and paternal chromosomes which separate during meiosis. He concluded that this could be "the physical basis of the Mendelian law of heredity."
1905: William Bateson coins the term "genetics" in a letter to Adam Sedgwick and at a meeting in 1906
1908: G.H. Hardy and Wilhelm Weinberg proposed the Hardy-Weinberg equilibrium model which describes the frequencies of alleles in the gene pool of a population, which are under certain specific conditions, as constant and at a state of equilibrium from generation to generation unless specific disturbing influences are introduced.
1910: Thomas Hunt Morgan shows that genes reside on chromosomes while determining the nature of sex-linked traits by studying Drosophila melanogaster. He determined that the white-eyed mutant was sex-linked based on Mendelian's principles of segregation and independent assortment.
1911: Alfred Sturtevant, one of Morgan's students, invented the procedure of linkage mapping which is based on the frequency of recombination. A few years later, he constructed the world's first chromosome map.
1913: Alfred Sturtevant makes the first genetic map of a chromosome
1913: Gene maps show chromosomes containing linear arranged genes
1918: Ronald Fisher publishes "The Correlation Between Relatives on the Supposition of Mendelian Inheritance" the modern synthesis of genetics and evolutionary biology starts. See population genetics.