2. 1901 – 10 - Hugo de Vries, Tshermak and Correns discovered Mendel’s long ignored paper “ Experiments with plants hybrids”
3. 1901 – Hugo de vries of Holland introduces the concept of mutations in organims 1902 – Karl Landsteiner disovered the AB blood group Archibald Garrod documented inborn errors associated with inheritance of recessive genes
4. 1903 – Walter Sutton observes that egg and sperm cells contain half the number of chromosomes 1908 – Thomas Hunt Morgan started extension work on fruit flies. Morgan came from a prominent Kentucky family.
5. Albert Calmette and Camille Guerin Develop a vaccine against tuberculosis called ( Bacillus Calmette Guerin ) the vaccine was put to use in 1921.
6. 1909 – Johanssen suggested the term gene 1910 – T.H .Morgan found that genes are carried on chromosomes. The word gene was taken from pangene referred by De vries. It was part of English language from 1911.
7. 1911 – 20 Time of war The second decade of the 20th century was time of great international tension that erupted into a war. Many researchers diverted their work from pure science to the war effort. Fritz Haber in 1918 a Nobel laureate in chemistry promoted Germany’s use of chemical weapons in world war I
8. The decade of the great war brought advances in areas of applied biology such as immunology bacteriology, food science and crop breeding. 1914 – Henry Hallett Dale isolated acetylcholine involved in sending nerve impulses
9. 1915 – Frederick Twort – English bacteriologist describes bacteriophages d Herelle identified bacteriophage and coined the term
10. 1918 – A world wide epidemic of influenza kills 25 million people far more than died as a result of world war I
11. 1921 - 30 1921 – Frederick Grant Banting and Charles Herbert Best isolated insulin from the pancreas of a dog. 1925 – A Tennesse court finds a biology teacher John Thomas guilty of violating a state law that bans the teaching of evolution.
12. 1926 – Walter Canon a Neurologist coins the term Homeostasis
13. 1928 – Alexander Fleming discovered Penicillin Fleming (centre) receiving the Nobel prize from King Gustaf V of Sweden (right), 1945
15. This decade marked a giant misstep for genetic science. 1928 George William Hunter classified five races of man different in each in instincts, social customs and to some extent structure The highest type of all Caucasians represented by civilized white inhabitants of Europe and America.
16. Darwin’s theory of evolution was being used in 1920 to teach racism in American high school students. Francis Galton – Charles Darwin’s cousin coined the term eugenics meaning well born or good heritage Galton believed that human species could be improved through careful genetic management.
17. This idea led to the thinking of the idea that certain kinds of people are inherently superior to others. This idea led to block immigrants from southern and eastern Europe on the grounds of their genetic unsuitability
18. Eugenics – minded public officials also took it upon themselves to rule that certain individuals considered genetically inferior should be surgically sterilized against their will for the good of society
19. Adolf Hitler seized power in Germany and his party enacted laws against those considered wither politically or genetically undesirable Nazi policies caused many scientist, educators and public health officials to reexamine ideas about race and eugenics.
20. In the late 19th century Bacteriologist Ernest Hankin has noticed that Hindu worshippers who drank the water of the sacred Ganges river did not contract Cholera As he investigated he found that the water also contained an antibacterial agent.
21. 1931- 40 Hard times and hard lessons The 1930 was difficult decade marred by a worldwide economic slum, great depression and by dictatorial and militaristic government in several parts o the world. Soviet union, Japan and Italy launched military conquests that led towards the horrors of world war II
22. Nazi policies caused many scientist educators, and public officials especially those of Jewish heritage fled Germany setting back that countrys research programmes
23. 1931 – BarabaraMclintock identified transposons Albert Bethe introduces the concept of pheromones the substances effect the physiology of another individual of the same species.
24. Sewall Wright proposes genetic drift as a factor in evolution 1933 – Shickel Painter and others rediscovered giant salivary chromosomes in Drosophila
25. 1935 – American Scientist Stanley crystallized tobacco mosaic virus 1938 – Warren Weaver director of Rockfeller institute Division of Natural sciences coins the term Molecular biology
26. 1939 – A war criminal Josef Mengele Became the director of Berlins institute of Hereditary biology and Racial Hygiene he sterilized 56,244 people as hereditary defectives
27. 1951- 60 Double helix decade The double helix molecules stands as the most prominent historical landmark in biological research between Gregor Mendel’s 19th century discoveries and the present day recombinant DNA and Bioengineering
28. 1951- James Watson and Francis Crick attended a lecture by Maurice Wilkins on X-ray crystallography of DNA
29. X- ray Crystallographer Rosalind Franklin produces the image of DNA 1952 – Immunologist Jones Salk began field trials of his experimental vaccine against Infantile paralysis also called Polio
30. 1953 – The Journal nature publishes Watson and Crick’s manuscript describing the double helix structure of DNA
31. 1955 – Salk’s Polio vaccine, having proven safe and effective was released for a vaccination program
32. 1958 - Kornberg isolated DNA polymerase was called Kornberg enzyme
33. 1961 – 70 Code breakers and Ecologists 1961 – Marshall W. Niremberg builds a strand of RNA from the base Uracil Monod & Jacob coined the term messenger RNA 1966 – Niremberg and collegues show that codon determines each of 20 amino acids that form proteins 1970 – Temin discovered Reverse transcriptase
34. 1971 - 1980 The field of molecular genetics changed radically as scientists achieved new means for probing measuring, synthesizing and ultimately manipulating DNA
35. 1972 – Paul Berg achieves the first recombinant DNA molecule 1978 – Boyer makes a synthetic version of the human insulin gene and inserts into the bacterium E.coli 1980 – U. S supreme court rules that genetically altered life forms can be patented
37. 1981 – 1990Biotech booms, AIDS looms The field of biotechnology accelerated in the 1980s in large part because of new tools for molecular biologists 1982 – the term AIDS is used for the first time 1983 – Stanley Prusiner introduces the term PrionsKarry Mullis invents PCR 1985 – Alec Jaffreys introduced “DNA finger printing” which soon enters court room.
38. 1986 – Robert Horvitz discovered genes controlling programmed cell death in the nemadoteC.elegans 1987 – The USA department of Energy establishes a research program to sequence the entire human genome 1990 – The human genome project begins work estimated cost 13 billion Gene therapy was used for the first time on human subject
39. 1991- 2000Sheep and Stem cells 1995 – O. J. Simpson a film actor and a foot ball of fame was convicted for the murder of his ex-wife and her friend by DNA analysis. A Virginia prisoner is the first person put to death after a conviction based on DNA evidence 1997 – Wilmut announces the cloning of sheep Dolly
40. 2000 – Human genome project was completed and was published in Nature journal
43. 2001 - 2100 Future Perspectives : The biological research in 20th century offers many great promises for the future and as many cautions The science of genetics once involved tracing neat rules in pea plants – lead to the emergence of R DNA technique
44. In the early 21stcentury Huntington’s disease took a toll. Many children still go blind from Vitaminedeficiency. Herat disease and diabetes play a dominant role. Cancers far better understood and more successfully treated than they were decades ago. Continue to disable and kill The earth species are becoming extinct at an alarming rate AIDS ravages the third world
45. What happened to Recombinant DNA technology ? Decades of success and failures. It has met opposition on religious and philosophical grounds. Recombinant DNA remains incredibly promising and dangerous too. Ultimately the bigger challenge that biologists will face in the future are sure to be cultural political ethical and moral rather than pure scientific.
