Timeline in Biology
520 BC – Alcmaeon of Croton distinguished veins from arteries and discovered the optic nerve.
c. 450 BC – Sushruta wrote the Sushruta Samhita, redacted versions of which, by the third century AD, describe over 120 surgical instruments and 300 surgical procedures, classify human surgery into eight categories, and introduce cosmetic surgery.
c. 450 BC – Xenophanes examined fossils and speculated on the evolution of life.
c. 380 BC – Diocles wrote the oldest known anatomy book and was the first to use the term anatomy.
c. 350 BC – Aristotle attempted a comprehensive classification of animals. His written works include Historion Animalium, a general biology of animals, De Partibus Animalium, a comparative anatomy and physiology of animals, and De Generatione Animalium, on developmental biology.
c. 300 BC – Theophrastos (or Theophrastus) began the systematic study of botany.
c. 300 BC – Herophilos dissected the human body.
130–200 – Claudius Galen wrote numerous treatises on human anatomy.
1543 – Andreas Vesalius publishes the anatomy treatise De humani corporis fabrica.
1600 – Jan Baptist van Helmont performed his famous tree plant experiment in which he shows that the substance of a plant derives from water, a forerunner of the discovery of photosynthesis.
1628 – William Harvey published An Anatomical Exercise on the Motion of the Heart and Blood in Animals
1651 – William Harvey concluded that all animals, including mammals, develop from eggs, and spontaneous generation of any animal from mud or excrement was an impossibility.
1655 – Robert Hooke saw cells in cork using a microscope.
1676 – Anton van Leeuwenhoek observed protozoa and calls them animalcules.
1677 – Anton van Leeuwenhoek observed spermatozoa.
1768 – Lazzaro Spallanzani again disproved spontaneous generation by showing that no organisms grow in a rich broth if it is first heated (to kill any organisms) and allowed to cool in a stoppered flask. He also showed that fertilization in mammals requires an egg and semen.
1771 – Joseph Priestley demonstrated that plants produce a gas that animals and flames consume. Those two gases are carbon dioxide and oxygen.
1801 – Jean-Baptiste Lamarck began the detailed study of invertebrate taxonomy.
1809 – Lamarck proposed a modern theory of evolution based on the inheritance of acquired characteristics.
1826 – Karl von Baer showed that the eggs of mammals are in the ovaries, ending a 200-year search for the mammalian egg.
1836 – Theodor Schwann discovered pepsin in extracts from the stomach lining; first isolation of an animal enzyme.
1838 – Matthias Schleiden proposed that all plants are composed of cells.
1839 – Theodor Schwann proposed that all animal tissues are composed of cells. Schwann and Schleinden argued that cells are the elementary particles of life.
1856 – Louis Pasteur stated that microorganisms produce fermentation.
1858 – Charles R. Darwin and Alfred Wallace independently proposed a theory of biological evolution ("descent through modification") by means of natural selection. Only in later editions of his works did Darwin used the term "evolution."
1858 – Rudolf Virchow proposed that cells can only arise from pre-existing cells; "Omnis cellula e celulla," all cell from cells. The Cell Theory states that all organisms are composed of cells (Schleiden and Schwann), and cells can only come from other cells (Virchow).
1865 – Gregor Mendel demonstrated in pea plants that inheritance follows definite rules. The Principle of Segregation states that each organism has two genes per trait, which segregate when the organism makes eggs or sperm. The Principle of Independent Assortment states that each gene in a pair is distributed independently during the formation of eggs or sperm. Mendel's trailblazing foundation for the science of genetics went unnoticed, to his lasting disappointment.
1898 – Martinus Beijerinck used filtering experiments to show that tobacco mosaic disease is caused by something smaller than a bacterium, which he names a virus.
1902 – Walter Sutton and Theodor Boveri, independently proposed that the chromosomes carry the hereditary information.
1905 – William Bateson coined the term "genetics" to describe the study of biological inheritance.
1907 – Hermann Emil Fischer artificially synthesized peptide amino acid chains and thereby shows that amino acids in proteins are connected by amino group-acid group bonds.
1911 – Thomas Hunt Morgan proposed that genes are arranged in a line on the chromosomes.
1928 – Alexander Fleming discovered the first antibiotic, penicillin
1930 – John Howard Northrop showed that the pepsin enzyme is a protein.
1932 – Hans Adolf Krebs discovered the urea cycle.
1933 – Tadeus Reichstein artificially synthesized vitamin C; first vitamin synthesis.
1938 – Marjorie Courtenay-Latimer discovered a living coelacanth off the coast of southern Africa.
1940 – Donald Griffin and Robert Galambos announced their discovery of echolocation by bats.
1944 – Oswald Avery shows that DNA carried the hereditary information in pneumococcus bacteria.
1948 – Erwin Chargaff showed 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 – The research group of Robert Robinson with John Cornforth (Oxford University) publishes their synthesis of cholesterol, while Robert Woodward (Harvard University) publishes his synthesis of cortisone.
1951 – Fred Sanger, Hans Tuppy, and Ted Thompson completed their chromatographic analysis of the insulin amino acid sequence.
1952 – Alfred Hershey and Martha Chase showed that DNA is the genetic material in bacteriophage viruses.
1952 – Rosalind Franklin concluded that DNA is a double helix with a diameter of 2 nm and the sugar-phosphate backbones on the outside of the helix, based on x ray diffraction studies. She suspected the two sugar-phosphate backbones have a peculiar relationship to each other.
1953 – After examining Franklin's unpublished data, James D. Watson and Francis Crick published a double-helix structure for DNA, with one sugar-phosphate backbone running in the opposite direction to the other. They further suggested a mechanism by which the molecule can replicate itself and serve to transmit genetic information. Their paper, combined with the Hershey-Chase experiment and Chargaff's data on nucleotides, finally persuaded biologists that DNA is the genetic material, not protein.
1961 – J. Heinrich Matthaei cracked the first codon of the genetic code (the codon for the amino acid phenylalanine) using Grunberg-Manago's 1955 enzyme system for making polynucleotides.
1961 – Joan Oró found that concentrated solutions of ammonium cyanide in water can produce the nucleotide adenine, a discovery that opened the way for theories on the origin of life.
1972 – Stephen Jay Gould and Niles Eldredge proposed an idea they call "punctuated equilibrium", which states that the fossil record is an accurate depiction of the pace of evolution, with long periods of "stasis" (little change) punctuated by brief periods of rapid change and species formation (within a lineage).
1974 – Manfred Eigen and Manfred Sumper showed that mixtures of nucleotide monomers and RNA replicase will give rise to RNA molecules which replicate, mutate, and evolve.
1974 – Leslie Orgel showed that RNA can replicate without RNA-replicase and that zinc aids this replication.
1982 – Stanley B. Prusiner proposed the existence of infectious proteins, or prions. His idea is widely derided in the scientific community, but he wins a Nobel Prize in 1997.
1986 – Rita Levi-Montalcini and Stanley Cohen received the Nobel Prize in Physiology or Medicine for their discovery of Nerve growth factor (NGF).
1990 – French Anderson et al. performed the first approved gene therapy on a human patient
1990 – Napoli, Lemieux and Jorgensen discovered RNA interference (1990) during experiments aimed at the color of petunias.
1990 – Wolfgang Krätschmer, Lowell Lamb, Konstantinos Fostiropoulos, and Donald Huffman discovered that Buckminsterfullerene can be separated from soot because it is soluble in benzene.
1995 – Publication of the first complete genome of a free-living organism.
1996 – Dolly the sheep was first clone of an adult mammal.
1999 – Researchers at the Institute for Human Gene Therapy at the University of Pennsylvania accidentally kill Jesse Gelsinger during a clinical trial of a gene therapy technique, leading the FDA to halt further gene therapy trials at the Institute.
2001 – Publication of the first drafts of the complete human genome
2002 – First virus produced 'from scratch', an artificial polio virus that paralyzes and kills mice.