Year / Event
-320 Theophrastus begins the systematic study of botany.
1658 Jan Swammerdam observes red blood cells under a microscope.
1663 Robert Hooke sees cells in cork using a microscope.
1668 Francesco Redi disproves theories of the spontaneous generation of maggots in putrefying matter.
1676 Anton van Leeuwenhoek observes protozoa and calls them “animalcules”.
1677 Anton van Leeuwenhoek observes spermatazoa.
1683 Anton van Leeuwenhoek observes bacteria.
1765 Lazzaro Spallanzani disproves many theories of the spontaneous generation of cellular life.
1771 Joseph Priestly discovers that plants convert carbon dioxide into oxygen.
1798 Thomas Malthus discusses human population growth and food production in “An Essay on the Principle of Population”.
1801 Jean Lamarck begins the detailed study of invertebrate taxonomy.
1809 Jean Lamarck proposes an inheritance of acquired characteristics theory of evolution.
1817 Pierre-Joseph Pelletier and Joseph-Bienaim'e Caventou isolate chlorophyll.
1828 Karl von Baer discovers the eggs of mammals.
1828 Friedrich Wohler synthesizes urea. This is the first synthesis of an organic compound.
1836 Theodor Schwann discovers pepsin in extracts from the stomach lining; the first isolation of an animal enzyme.
1837 Theodor Schwann shows that heating air will prevent it from causing putrefaction.
1838 Matthias Schleiden discovers that all living plant tissue is composed of cells.
1839 Theodor Schwann discovers that all living animal tissue is composed of cells.
1856 Louis Pasteur states that microorganisms produce fermentation.
1858 Charles R. Darwin and Alfred Wallace independently propose natural selection theories of evolution.
1858 Rudolf Virchow proposes that cells can only arise from pre-existing cells.
1862 Louis Pasteur convincingly disproves the spontaneous generation of cellular life.
1865 Gregor Mendel presents his experiments on the crossbreeding of pea plants and postulates dominant and recessive factors.
1865 August Kekule realizes that benzene is composed of carbon and hydrogen atoms in a hexagonal ring.
1869 Friedrich Miescher discovers nucleic acids in the nuclei of cells.
1874 Jacobus van’t Hoff and Joseph Achille Le Bel advance a three-dimensional stereochemical representation of organic molecules and propose a tetrahedral carbon atom.
1876 Oskar Hertwig and Hermann Fol show that fertilized eggs possess both male and female nuclei.
1884 Emil Fischer begins his detailed analysis of the compositions and structures of sugars.
1898 Martinus Beijerinck uses filtering experiments to show that tobacco mosaic disease is caused by something smaller than a bacteria which he names a virus.
1906 Mikhail Tsvett discovers the chromatography technique for organic compound separation.
1907 Ivan Pavlov demonstrates conditioned responses with salivating dogs.
1907 Emil Fischer artificially synthesizes peptide amino acid chains and thereby shows that amino acids in proteins are connected by amino group-acid group bonds.
1911 Thomas Morgan proposes that Mendelian factors are arranged in a line on chromosomes.
1926 James Sumner shows that the urease enzyme is a protein.
1928 Otto Diels and Kurt Alder discover the Diels-Alder cycloaddition reaction for forming ring molecules.
1929 Phoebus Levene discovers the sugar deoxyribose in nucleic acids.
1929 Edward Doisy and Adolf Butenandt independently discover estrone.
1930 John Northrop shows that the pepsin enzyme is a protein.
1931 Adolf Butenandt discovers androsterone.
1932 Hans Krebs discovers the urea cycle, now known as the Krebs Cycle.
1933 Tadeus Reichstein artificially synthesizes vitamin C; the first vitamin synthesis.
1935 Rudolf Schoenheimer uses hydrogen-2 as a tracer to examine the fat storage system of rats.
1935 Wendell Stanley crystallizes the tobacco mosaic virus.
1935 Konrad Lorenz describes the imprinting behavior of young birds.
1937 Theodosius Dobzhansky links evolution and genetic mutation in “Genetics and the Origin of Species”.
1938 A living coelacanth is found off the coast of southern Africa.
1940 Donald Griffin and Robert Galambos announce their discovery of sonar echolocation by bats.
1942 Max Delbruck and Salvador Luria demonstrate that bacterial resistance to virus infection is caused by random mutation and not adaptive change.
1944 Oswald Avery shows that DNA carries the genetic code in pneumococci bacteria.
1944 Robert Woodward and William von Eggers Doering synthesize quinine.
1948 Erwin Chargaff shows that in DNA the number of guanine units equals the number of cytosine units and the number of adenine units equals the number of thymine units.
1951 Robert Woodward synthesizes cholesterol and cortisone.
1952 Alfred Hershey and Martha Chase use radioactive tracers to show that DNA is the genetic material in bacteriophage viruses.
1952 Fred Sanger, Hans Tuppy, and Ted Thompson complete their chromatographic analysis of the insulin amino acid sequence.
1952 Rosalind Franklin uses X-ray diffraction to study the structure of DNA and suggests that its sugar-phosphate backbone is on its outside.
1953 James Watson and Francis Crick propose a double helix structure for DNA.
1953 Max Perutz and John Kendrew determine the structure of hemoglobin using X-ray diffraction studies.
1953 Stanley Miller shows that amino acids can be formed when simulated lightning is passed through vessels containing water, methane, ammonia, and hydrogen.
1955 Severo Ochoa discovers RNA polymerase enzymes.
1955 Arthur Kornberg discovers DNA polymerase enzymes.
1960 Juan Oro finds that concentrated solutions of ammonium cyanide in water can produce the nucleotide organic base adenine.
1960 Robert Woodward synthesizes chlorophyll.
1967 John Gurden uses nuclear transplantation to clone a clawed frog; first cloning of a vertebrate.
1968 Fred Sanger uses radioactive phosphorous as a tracer to chromatographically decipher a 120 base long RNA sequence.
1970 Hamilton Smith and Daniel Nathans discover DNA restriction enzymes.
1970 Howard Temin and David Baltimore independently discover reverse transcriptase enzymes.
1972 Robert Woodward synthesizes vitamin B-12.
1972 Stephen Jay Gould and Niles Eldredge propose punctuated equilibrium effects in evolution.
1974 Manfred Eigen and Manfred Sumper show that mixtures of nucleotide monomers and RNA-replicase will give rise to RNA molecules which replicate, mutate, and evolve.
1974 Leslie Orgel shows that RNA can replicate without RNA-replicase and that zinc aids this replication.
1977 John Corliss, Jack Dymond, Louis Gordon, John Edmond, Richard von Herzen, Robert Ballard, Kenneth Green, David Williams, Arnold Bainbridge, Kathy Crane, and Tjeerd van Andel discover chemosynthetically based animal communities located around submarine thermal springs on the Galapagos Rift.
1977 Walter Gilbert and Allan Maxam present a rapid gene sequencing technique which uses cloning, base destroying chemicals, and gel electrophoresis.
1977 Fred Sanger and Alan Coulson present a rapid gene sequencing technique which uses dideoxynucleotides and gel electrophoresis.
1978 Fred Sanger presents the 5,386 base sequence for the virus $\phi$X174 —- first sequencing of an entire genome.
1983 Kary Mullis invents the polymerase chain reaction.
1984 Alec Jeffreys devises a DNA fingerprinting method.
1985 Harry Kroto, J.R. Heath, S.C. O’Brien, R.F. Curl, and Richard Smalley discover the unusual stability of the carbon-60 Buckminsterfullerine molecule and deduce its structure.
1990 Wolfgang Kratschmer, Lowell Lamb, Konstantinos Fostiropoulos, and Donald Huffman discover that Buckminsterfullerine can be separated from soot because it is soluble in benzene.