the krebs cycle
To conduct research there proved impossible. Full professors, locked in power struggles, had no ambition to train students for excellence and the will to advance science. The teacher in charge of reviewing the report prepared by Ishigami, with great sacrifice, had locked it in a drawer never to come into light.

容疑者Xの 献身

Table of Contents

Metabolism and macromolecules

 Antoine Danchin  & Disclaimer.

Contemporary scientific ideas related to biology are developed on this site. As it is intended to be informative, it requires a slow and thorough reading.

This page represents a biased selection of biology-related dates, obtained by compiling many sources, often using original texts and not the WWW; the information selected avoids as much as possible the use of Wikipedia, which by construction is the result of a process analogous to anonymous voting, and evolves over time to reflect an average consensus of what knowledge is rather than the reality of knowledge. We have taken care to verify the information as much as possible and rewrite it when necessary, but its content still contains many errors.

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1920 is a turning point in the history of biology. Until then, Europe had been at the centre of most discoveries, with specific emphasis on chemistry in Germany, evolution in the United Kingdom, zoology in Italy, microbiology in France, and genetics in Russia. The first World-War completely changed the picture: millions of young men died in France, Germany and Great Britain, and social unrest in Russia led to the creation of the Soviet Empire. The finances of Europe were in extremely poor condition. The pursuit of research had therefore hard times in Europe, while the increased wealth in America led to the flourishing of many laboratories. As early as this date several prominent European scientists started to emigrate to the USA. The trend was further stimulated by the awful birth and development of nazism in Germany, which culminated with the election of Hitler as a chancellor in 1933, in a context where the soul of central Europe was mainly of jewish descent. As a consequence, the centre of the development of biology shifted to the USA, triggered by first generation Americans, in a trend which is still quite visible today. It seemed to us important, in this context, to present not only positive facts about biology, but also misleading trends, fakes and unethical behaviour. It is important to note that, during this period, a general theory of « degeneracy » both of individuals and of races was often favored. This had an impact not only in genetics or anthropology, but also in statistics. In parallel, the development of Lyssenkism in Soviet Union and its satellite countries destroyed the local development of genetics, and delayed for decades the advent of modern biology there. Science is created by human beings, in precise socio-political contexts, and it is far from the perfect image that some would like to convey. This moment of history witnesses many fundamental developments in the domains of catalysis, metabolism, cytology, evolution. Most are very well known and cannot be developed here. We have therefore chosen to place in the limelight discoveries or events that are less well known, but have had important positive or negative contributions to the development of biology. Remembering past work is critical to go against the present day arrogance of some, who reinvent the wheel while claming that they have made great contributions to science!

1920 In line with this date as a turning point in the history of Biology, Hans Winkler (1877 - 1945), professor of Botany at the University of Hamburg, coins in his book Verbreitung und Ursache der Parthenogenesis the term Genom, to indicate the whole set of genes of an organism.

1920 Loewi shows that a stimulating and inhibitory substance is released from terminal branches of nerve fibers. This discovery leads to the concept of nerve impulse transmission across junctions by means of chemical mediators, later named neurotransmitters.

1920 Henry Eliot Howard (1873 - 1940) an obscure English bird watcher, convinces the scientific world in his Territory in bird life that, among other things, song is used by male birds to mark their territory. He coins the word "territoriality" to describe the behavior of male birds and began to investigate the territorial behavior of mating birds. Territoriality is typically manifested by aggression toward intruders.

1921 Spemann describes the "organizer" effect of the amphibian embryo dorsal lip region.

1921 Alfred F Hess (1875 - 1933) and Lester J Unger (1889 - 1974) show that by simply exposing rachitic children to sunlight, they are able to cure them of the disease. By this time, rickets was still a severe problem in Scotland and in parts of northern Europe. As a consequence of this work, by the early 1920s two methods could be used to cure rickets: cod-liver oil and exposure to sunlight or ultraviolet light.

1921 d'Hérelle publishes Le bactériophage : Son rôle dans l'immunité, where he reports his observations and the techniques used for the study of bacteriophages, and where he postulates intracellular multiplication of the virus.

1921 Morgan estimates that genes have a diameter of 20-70 microns. The work of Harriet Ephrussi-Taylor (1918 - 1968), analyzing gene inactivation with X-rays, will show later that genes must be much smaller.

1921 John Newport Langley (1852 - 1925) distinguishes functionally and gives a detailed description of the autonomic nervous system.

1921 Loewi, and independently Henry Hallett Dale (London, 1875 - 1968) isolate a diffusible substance (named "Vagusstoff" by the former) released by the vagus nerve.

1921 Alfred Newton Richards (1876 - 1966) establishes in great detail the nature of renal glomerular filtration and of selective tubular re-absorption. His studies were restricted to amphibian kidney until 1941.

1921 Frederick Gowland Hopkins (Eastbourne, 1861 - 1947) isolates a substance which he names glutathione, widely distributed in the cells of plants and animals that are rapidly multiplying. Among his other outstanding contributions to science was his discovery of a method for isolating tryptophan and for identifying its structure.

1921-1922 Frederick Grant Banting (Alliston, Canada 1891- killed in an air disaster in Newfoundland, 1941), Charles Herbert Best (West Pembroke, Maine, USA, 1899 - 1978) and John James Rickard Macleod (Cluny, Scotland, 1876 - Aberdeen, 1935) discover and isolate insulin and further study its physiological properties.

1922 McCollum carries on the naming of vitamins using alphabetical letters while showing that experimentallly that rickets is caused by lack of a new natural factor present in food, vitamin D. In this work he follows the observations of British physician Edward Mellanby. From his own work on isolating vitamin A, McCollum had found that certain foods may contain more than one vitamin. Following up on Mellanby's findings he tried by heating and aerating the oil to destroy its vitamin A to discover what else cod-liver oil might contain. As expected, the treated oil no longer cured night blindness (due to lack of vitamin A). But it did remain effective against rickets. This is how vitamin D was discovered.

1922 Kopec demonstrates that pupation in the gypsy moth (Lymantria dispar) is conditioned by an agent in the body fluid that originates in the brain. Animals, de-brained before the head critical period formed, stay as permanent larvae.

1922 Joseph Erlanger (San Francisco, California, 1874 - 1965) and Herbert Spencer Gasser (Platteville, Wisconsin, 1888 - 1963), having adapted the cathode-ray oscillograph for the study of nerve action potentials, find that the rates of conduction of mammalian nerve fibers correspond to the thickness of their sheaths.

1922 Walter Garstang (1868 - 1949), in contrast with the widely held view of Haeckel, recognizes that ontogeny does not always recapitulate phylogeny and later proposes that chordates evolved from organisms resembling ascidians. This important work is still not understood, as we still witness popular views of recapitulation, not only in mass media papers but also in scientific articles.

1922 Building on a work he started in 1913, the Norwegian psychologist Thorleif Schjelderup-Ebbe (Kristiania, Norge 1894 - Oslo 1976) establishes social dominance hierarchies (pecking orders) in domestic fowl.

1922 Leopold Ruzicka (Vukovar, Croatia, 1887 - Zürich, 1976) recognizes isoprene as the building block of carotenoids as well as many other natural products.

1922-1923 Warburg reports first measurements on the quantum efficiency of photosynthesis. Warburg's manometric apparatus becomes a standard tool for measuring metabolism in living cells.

1923 Johannes Nicolaus Brønsted (Varde, 1879 - 1947) defines acids as substances which act as proton sources, and bases as substances which act as proton acceptors, regardless of the solvent.

1923 Independently, Thomas Lowry (1874 - 1936) formulates his theory of acids and bases.

1923 Bjerrum uses the strength constants of acids and bases to study the dissociation of other compounds.

1923 George Charles de Hevesy (Budapest, 1885 - Freiburg im Breisgau, 1966) initiates in Copenhagen research concerned with isotopic separations. Together with Coster, he discovers the element hafnium. He pioneers work in the use of isotopic indicators both in inorganic and life sciences. Later, in Freiburg, he was to be involved in the first clinical use of isotopes.

1923 David Keilin (1887 - 1963) rediscovers histohematins (cytochromes) and demonstrates changes in their oxidation state during respiratory activity.

1923 RO Herzog (Vienna 1878 - Zürich 1935) and Willi Jancke (? - ?) apply their improvement of new X-ray crystallography techniques in an article on the structure of the cellulose and silk fibre, Röntgenspektrographische Beobachtungen an Zellulose

1923 Thunberg proposes that water is the reducing agent in photosynthesis in an oxidation-reduction reaction in which carbon dioxide is reduced and water is oxidized. He also studies the oxidative degradation of foodstuffs in animals.

1923 Lemuel Roscoe Cleveland (1892 - 1969) describes the mutualistic relationship between termites and their intestinal zooflagellates. He further analyses the effects of oxygenation and starvation on the symbiosis between the termite Termopsis, and its intestinal flagellate protists: Symbiosis between Termites and Their Intestinal Protozoa. Proc Natl Acad Sci U S A. 1923 9: 424–428

1924 Hermann Staudinger (Worms, 1881 - 1965), who proposed in 1920 that colloids were often large polymers proposes to name them Makromoleküle (macromolecules) and insists on the facts that their atoms are linked by "normal valence" (i.e. in our present terms, covalent bonds).

1924 Feulgen publishes his “Plasmalreaktion”, which he had carried out together with his assistant Kurt Voit (1895 - 1978) allowing one to visualize DNA in the nucleus of cells. All nuclei (animal and plant) stain violet after hydrolysis and staining with Schiff 's reagent, the material is then squashed in acetocarmine or aceto-orcein.

1924 Hans Berger (Neuses, near Coburg, Thuringia 1873 - Jena, 1941) devises equipment to make the first encephalograms (measurements of brain waves) of human subjects.

1924 Aleksandr Ivanovich Oparin (Moscow, 1894 - 1980) publishes a small book on chemical evolution where he advances a heterotroph theory of the origin of life.

1924 Philipp Stöhr (1891 - 1979) professor at the University of Bonn, and the son of the anatomist of the same name, obtains the development of an embryonic heart by self-differentiation of trunk mesoderm tissue.

1924 Felix Bernstein (Halle, 1878 - Zürich, 1956), a mathematician known for the Bernstein-Cantor-Schröder theorem on the equivalence of sets (1897) uses statistics to predict the way blood groups are inherited (inheritance of multiple alleles at one locus).

1924 Bernardo Alberto Houssay (Buenos Aires, 1887 - 1971) investigates the role of the hypophyse in the regulation of carbohydrate metabolism and in diabetes.

1924-1925 Theodor (The) Svedberg (Fleräng, Sweden 1884 - 1971) invents the ultracentrifuge and uses it to determine the sedimentation rates of proteins. This was to play a considerable role in the establishment of the modern view of what are macromolecules (creation of Molecular Biology).

1924-1928 Hans Karl August Simon von Euler-Chelpin (Augsburg, Germany, 1873 - 1964) develops his studies on vitamin A and carotene, using marked vitamin A.

1925 Joseph Barcroft (Glen, Newry, 1872 - 1947) while studying the role of hemoglobin in blood, demonstrates its storage and release by organs such as the spleen.

1925 Fritz Baltzer (Berne, 1884 - 1974), a former student of Boveri, discovers that sex determination in some animals is not chromosomal and that juveniles can be sexually ambipotent.

1925 Hans Molisch (Brünn (Brno), 1856 - 1937), Czechoslovakian botanist in Vienna, obtains the production of oxygen by illuminating preparations of dried leaves.

1925 Cyrus Hartwell Fiske (1890 - 1978) and Yellagaprada SubbaRow (1895 - 1948) establish a colorimetric determination of phosphorus in living organisms.

1925 George Edward Briggs (1893 - 1985) and John Burdon Sanderson Haldane (1892 - 1964) make important refinements in the theory of enzyme steady-state kinetics.

1925 Alfred James Lotka (Lemberg, Osterreich, 1880 - New York, 1949) publishes his Elements of Physical Biology that were to play a considerable role in population genetics (and in mathematics as well).

1925 George Richards Minot (Boston, USA, 1885 - 1950) and William Parry Murphy (Stoughton, Wisconsin, 1892 - 1987) discover that feeding raw liver had a pronounced effect in the treatment of pernicious anemia. This discovery led to the eventual isolation of vitamin B12 and the identification of yet another vitamin deficiency disease.

1925 Evert Gorter (Utrecht 1881 - Leiden 1954) and François Grendel (1897 - 1969), two Dutch scientists, extract membrane lipids from a known number of red blood cells and calculate the corresponding surface area. Then they create a monolayer of lipids on water: the surface area was two times that of the surface area of red blood cells. They conclude that membranes consist of two layers of lipids. This is the beginning of the bilayer theory of biological membranes.

1925 William Rowan (1891 - 1957) after emigrating to Canada in 1919, demonstrates the effect of photoperiod on on birds' physiological readiness for mating and migration.

1925 Raymond Arthur Dart (Toowong, Brisbane, Australia, 1893 - 1988) discovers the "Taung Baby" fossil, now classified as Australopithecus africanus. The find was especially significant because it included a rough cast of the individual's brain.

1925-1928 G Koller (? - ?) and Earle Bryant Perkins (1901 - 1985), by means of blood transfusions, obtain evidence of the presence of hormone-like substances regulating the activity of chromatophores in crustaceans (Crago vulgaris).The Perkins Glacier on the coast of Antarctica's Marie Byrd Land is named for him.

1925-1930 Levene elucidates the structure of mononucleotides and suggests that they are the building blocks of nucleic acids. He also isolates the carbohydrate portion of nucleic acids and distinguishes deoxyribose from ribose. He thinks that nucleic acids are complexes of a tetrad made of the four nucleotides. This erroneous view was to delay significantly the discovery of the structure of DNA.

1926 Samuel Ottmar Mast (1870 - 1947) publishes the "tail contraction model" to explain the mechanism of amoeboid movement. This study led to the formulation of many useful concepts for understanding other protoplasmic movements, such as cytokinesis.  

1926 Paul De Kruif (1890 - 1971) trained as a bacteriologist at the University of Michigan, and working on gas gangrene during the first World War in France, publishes a book popularising microbiology, Microbe Hunters, that had a considerable influence on the interest for the field. It was also the demonstration that there was a bridge between "The two cultures" (CP Snow) that were supposed to separate Science from Literature and Arts.

1926 Otto Loewi and Ernst Navratil (1902–1979) identify Vagusstoff as acetylcholine.

1926 Based on his own scientific observations and on the study of collected plants, Vavilov works out a theory of the origin of cultivated plants, according to which the cultivated flora appeared and was developed within relatively few geographic centers located mostly in mountainous regions. Vavilov later helped to establish seven centers for collecting seeds in the world. Vavilov's expeditions were targeted at verification of this theory. Later on, numerous Soviet and foreign expeditions were organized according to his plans. Vavilov's seed collection, an important genetic resource for the whole world, is housed today in St. Petersburg, Russia, and is in danger of degenerating. Subsequently, as a geneticist opposing the views of Lysenko (whom he had initially accepted in his laboratory), Vavilov was harshly persecuted during Stalin's dictature until his untimely death.

1926 Kenjiró Fujii (1866 - ?) in a report of the Japanese Association for the Advancement of Science describes the coiled structure of the chromosomes in the nucleus. At certain stages of the cell cycle, two filaments are seen to be coiled around each other.

1926 Fritz Warmolt Went (1903 - 1990) extracts the substance present in coleoptile tips (protective sheath enclosing the shoot tip and embryonic leaves of grasses) by placing them on agar for an hour, then discarding the tips and using the agar to produce growth in the decapitated coleoptiles. This is the first growth factor to be isolated.

1926 Archibald Vivian Hill (Bristol, 1886 - 1977) uses a thermocouple to measure the heat produced by stimulated nerve fibers. He shows that oxygen is consumed in the recovery phase of muscle contraction and is not directly required for contraction. Further work by Hill led others to the conception of the phenomenon of cooperativity in multisubunit proteins (Hill's coefficient), after his studies of the binding of oxygen to hemoglobin.

1926 (Lodewijk) Louis Bolk (Overschie, Netherlands, 1866 - Amsterdam, 1930) publishes La récapitulation ontogénétique comme phénomène harmonique. This work transmits the Haeckelian tradition of a kinship between ontogeny and phylogeny.

1926 James Batcheller Sumner (Canton, Massachusetts, 1887 - 1955) crystallizes the enzyme urease and proves it to be a protein. This can be considered as one of the last experimental demonstration of the continuity between physics and biology putting together the world of "colloids" and the world of "crystals".

1925 Gilbert Smithson Adair (1896 - 1979) finds in a series of papers that the molecular mass of hemoglobin is 67,000. He begins to describe the reversible binding of oxygen to the protein (Adair's equation), in a way that was the basis for the theory of allostery, forty years later.

1926 Barend Coenraad Petrus Jansen (1884 – 1962) and Willem Frederik Donath (1889 – 1957) isolate crystalline aneurin (thiamin, vitamin B1) from rice polishings, but their work does not identify the sulfur atom in the molecule.

1927 Emil Bozler (1901- 1995) demonstrates that the nerve net of cnidarians is made up of separate cells connected by synaptic junctions. He also studies electrical aspects of muscle contraction and the role of calcium and magnesium in contraction and relaxation.

1927 Calvin Bridges (1889 - 1938), a geneticist, precursor of the discoverers of homeogenes, discovers in Drosophila the mutation bithoraxoïd (bxd) that modifies the aspect of the first abdominal segment of the adult insect.

1927 Adolf Otto Reinhold Windaus (Berlin, 1876 - 1959) analyzes bile acids and identifies ergosterol as the parent substance of vitamin D.

1927 Erik Anderson Stensiö (1891 - 1984) reconstructs a fossil Cephalapsid (an ostracoderm) and suggests that it is a vertebrate prototype. He conceives the lepidomorial theory as means of explaining the evolution of development of the vertebrate dermal and oral skeleton. The theory is a pattern-based theory that provides a homological framework in comparing dental papillae and their products, and it provides an explanatory mechanism for such relationships a posteriori.

1927 George Ellett Coghill (Beaucoup, Illinois, 1872 - Gainesville, Florida, 1941) begins to investigate the innate behavioral patterns of lower vertebrates, including salamanders as well as early embryonic somatic movements in birds and in mammals other than man.

1927 In Pavlov's school, Anatolii Georgievich Ivanov-Smolensky (1895 - Moscow 1982) publishes On the methods of examining the conditioned food reflexes in children and in mental disorders, a classic in psycho-physiology, Brain 50: 280.

1927 Georgii Dmitriyevich Karpchenko (Velsk, 1899 -1941) obtains a tetraploid hybrid between the radish Raphanus sativus, and the cabbage, Brassica oleracea, thus creating the new species "Raphanobrassica". This is a first work in Soviet Union demonstrating that plants can behave in a way purposedly oriented by man.

1927 Artificial transmutation of genes is reported by Lewis John Stadler (1896 - 1954) in maize and Hermann Joseph Muller (New York, 1890 - 1967) in Drosophila by means of X-rays.

1927 Improving methods discovered earlier, Charles Robert Harington (1897 - 1972) synthesizes thyroxine at a high yield.

1927 Landsteiner discovers new blood groups, the M and N groups.

1927 Theophilus Shickel Painter (Salem, Viriginia, 1889 - Fort Stockton, Texas, 1969) finds a chromosome deficiency in mice which, along with genetic evidence, provides the first case of localizing a specific gene to a particular chromosome in mammals. Painter is however better known for his work on the genetics of Drosophila and its relation to chromosome structure.

1927-1928 Philip Eggleton (1903 -1954) and Grace Palmer Eggleton (1901 - 1970), followed by Fiske and SubbaRow recognize that phosphate is liberated from an organic compound during rabbitt muscle contraction. They name "phosphagen" this reservoir of energy. Phosphagen was later identified as phosphocreatine.

1927-1928 Hideyo Noguchi (1876 - Accra, Gold Coast, 1928) goes to Accra, Ghana, to work on yellow fever, a disease which he wrongly believes is caused by a spirochete and dies there from the disease he was keen to understand.

1927-1929 Corneille Jean François Heymans (Ghent, 1892-1968) investigates the role of the carotid and aortic reflexes in respiratory control.

1927-1930 The Institut de Biologie Physico-Chimique is created in Paris, funded by Edmond de Rothschild. Its first director is a physicist, the discoverer of an experimental view of atoms, Jean Perrin. This Institute aims at putting together Physics, Chemistry and Biology, to follow the ideas of Claude Bernard. The structure of this institute decided of the plan for the conception of the French Centre National de la Recherche Scientifique (CNRS).

1928 Emil Heitz (1892 - 1965), fixing and staining plant material, visualises, using the microscope, in moss nuclei (the liverwort Pellia epiphylla (Jungermaniidae)) chromosomal regions that do not undergo postmitotic decondensation, which he names heterochromatin. His contributions further extends to the study of chloroplasts and polytene chromosomes.

1928 Franz Volhard (München, 1872 - Frankfurt am Main, 1950) suggests that a substance in the kidney may be responsible for some cases of hypertension.

1928 Josias Braun-Blanquet (1884 - 1980) publishes an influential book on plant physiology, Pflanzensoziologie (English translation: 1932).

1928 Fredrick Griffith (London, ?- 1941), trying to establish a vaccine against pneumonia, discovers a "transforming principle" in pneumococci (Streptococcus pneumoniae) that is capable of transforming nonvirulent (rough) strains into virulent (smooth) strains.

1928 Hans von Euler-Chelpin (Augsburg, 1873 - Stockholm, 1964), already famous for his work on catalysis and fermentation, prepares pure carotene and demonstrates its high vitamin A activity.

1928 Gustav Heinrich Ralph von Koenigswald (Berlin, 1902 - 1982) defends his thesis dissertation "Das Rotliegende der Weidener Bucht" (the permian redbeds in the Weidener Bucht, an area located in the northeast of Bavaria) and soon starts as a young scientist to work with the Netherlands Geological Survey in Java, where important discoveries on the origin of Man were to happen.

1928 Albert von Szent-Györgyi (Budapest, Hungary, 1893 - 1986) pioneering the study of biological oxidation mechanisms, isolates from adrenals a substance that he later found to be identical with vitamin C. He names the product, now known as ascorbic acid, hexuronic acid. Ascorbic acid is not hexuronic acid but a reduced derivative.

1928 Went develops a method of quantifying the plant growth substance he has isolated two years earlier. His results suggest that the curvatures of stems are proportional to the amount of growth substance in the agar. This test is called the "avena curvature test".

1928 Alexander Fleming (Lochfield, Scotland, 1881 - London, 1955) while working on the influenza virus, discovers accidentally the antibacterial action of a diffusible molecule produced by a microscopic fungus, penicillin. Fifteen years were necessary to put this discovery into medical practice.

1928 Wieland and Windaus elucidate the structure of the cholesterol molecule.

1928-1933 Warburg establishes the iron-porphyrin structure of the respiratory co-enzyme.

1929  Jean Piaget (Neuchâtel, Swizerland, 1896 - Geneva, 1980), initially trained as a specialist of the molluscs of the Geneva lake publishes La représentation du monde chez l'enfant (The Child's Conception of the World), a book that was to be very influential in the way we perceive learning in humans.

1929 Karl Lohmann (1898 - 1978), following previous work of Fiske and SubbaRow isolates ATP from muscle extracts. Within two years he shows that it contains two moles of phosphoric acid, one mole of adenine and one mole of ribose-5-phosphate.

1929 Trofim Denissovitch Lysenko (1898 1976), revives the old way of accelerating germination of plants by submitting seeds to cold, advocated by Ivan Vladimirovitch Mitchourine (Verchina, near Dolgoïe, gouv. of Riazan, 1855 - Kozlov, today Mitchourinsk, 1935) (vernalisation). He incorrectly interprets this true epigenetic phenomenon of adaptation as a genetic phenomenon, and starts a crusade againts the "Mendelist-Morganist" genetics, that was to culminate with Stalin's support with the emprisonment and death of most of the genetics school in Soviet Union. He further develops the Mitchourinian theory of the "mentor" (graft or addition of strong plants to a bunch of weaker ones) to improve the progeny by passing over the "good" properties of the plants. It should be noticed that this fantastic view has been held by influential thinkers such as Piaget, in the domain of psychology, and is somewhat still influential today in certain circles.

1929 Adolf Friedrich Johann Butenandt (1903 - 1995) and Edward Adelbert Doisy (Hume, Illinois, 1893 - 1986) isolate the first sex hormone, estrone, from urine.

1929 Walther Vogt (1888 - 1941) uses vital dyes to construct fate maps of newt Triturus embryos. Placing small vital dye marks on the surface of amphibian embryos at various stages of development he analyzes the movements and fates of various regions of the embryo.

1929 Sturtevant and Sterling Emerson (1900 - 1988) show that much of the extraordinarily complex genetics of the evening primrose (Oenothera) can be interpreted as due to translocations of groups of genes, following a model elaborated by John Belling (Aldershot, UK 1866 - 1933) for the jimsonweed, Datura, with the technique he had developed, the iron-acetocarmine staining technique, which facilitated detailed study of chromosomal structures. As a consequence of their work it becomes apparent that many of the "mutations" that De Vries had found in this organism were not genuine mutations but segregation products from the complex translocations of chromosome arms in Oenothera.

1929 William Bosworth Castle (1897 - 1990) shows that the substance responsible for preventing pernicious anemia derives from the combination of an "intrinsic factor" in the gastric juice and an "extrinsic factor" in the diet. This antianemic factor then stores in the liver. Extrinsic factor was later proven to be vitamin B 12.

1929 Jacques Forestier (1890 - 1978) introduces gold therapy in rheumatoid arthritis: L'aurothérapie dans les rhumatismes chroniques.

1930 Einar Lundsgaard (1899 - 1968) proves that muscles can contract in the presence of iodoacetate, which prevents lactic acid formation.

1930 Cornelis van Niel (1897 - 1985) while studying anaerobic bacteria that use hydrogen sulfide (H2S) instead of H2O in photosynthesis, finds that the bacteria generate sulfur (S8) as a byproduct. Following the earlier hypothesis of Thunberg, this result leads him to propose that photosynthesis consists of two separate reactions. The first is oxidation of a compound with the general formula H2A (for example, (H2S) or H2O) with the concomitant generation of protons (H+) and electrons (e-). This reaction requires light to proceed. The second reaction uses the protons and electrons generated by the first reaction to reduce CO2 and produce carbohydrates and water. This provides a rationale for the mechanism of photosynthesis.

1930 Max Theiler (Pretoria, 1899 - 1972), by demonstrating that mice were susceptible to the intracerebral inoculation of the yellow fever agent, establishes the agent of yellow fever as a virus contrary to the opinion generally held around him (in particular by his former colleague, Hideyo Noguchi).

1930 Stadler devises and perfects methods for determining spontaneous mutations rates in maize, finding that different genes mutate at widely different rates.

1930 Gavin Rylands De Beer (London, 1899 - Alfriston, Sussex, 1972) publishes Embryology and evolution where he analyzes the relationships between ontogeny and phylogeny.

1930 Sewall Wright (1889 - 1988), best known for his "shifting balance theory", studies the mathematics of evolutionary changes in living organisms populations.

1930 Publication of Ronald Aylmer Fisher's (London, 1890 - Adelaide, Australia, 1962) The Genetical Theory of Natural Selection. While being extremely influential in the domain of statistics (and an excellent mathematician in the domain), Fisher was to expose also a very dark side, because of his extremely biased emphasis on eugenics (with particularly horrible consequences during this period of the XXth century).

1930-1933 John Howard Northrop (1891 - 1987) crystallizes pepsin and trypsin and proves that they are proteins.

1930-1935 John Tileston Edsall (Philadelphia, 1902 - 2002) and Alexandeer von Muralt (1903 - 1990) isolate myosin from muscle. Later, Edsall had a strong influence on the development of biochemistry, and was an important editor of The Journal of Biological Chemistry.

1931 Vladimir Aleksandrovich Engelhardt (1894 - 1984) discovers that phosphorylation of ATP is coupled to respiration, a process now known as "oxidative phosphorylation".

1931 Warren Lewis and his wife Margaret characterize the process of entry of compounds and particles in cells, known as pinocytosis (from the Greek "πεινω" I drink).

1931 Harriett B Creighton (1909 - 2004) and Barbara McClintock (1902 - 1992) demonstrate both cytological chromatid exchange and exchange of genetic loci as a result of the same meiotic event, a cytological proof for crossing-over in maize. A similar demonstration is made by Curt Stern (Hamburg, 1902 - 1981) in Drosophila.

1931 Kurt Gödel (Brünn, 1906 - Princeton, 1978) establishes the principle of indecidability in arithmetics. This remarkable work demonstrates that, even in the science of whole numbers (integers) mathematics is not a tautology. For this work Gödel uses the concept of coding, distinguishing between the concept and its label (as a word in a given language, or, as any type of string of symbols). This is at the root of the powerful alphabetic metaphor that underlies molecular biology and the science of genetics of genomes.

1931 Carl Linus Pauling (1901 - 1994) publishes The Nature of the Chemical Bond, which describes the basis for understanding how macromolecules can be stable at ordinary temperature.

1931 Wright presents the first unified picture of evolution in terms of Mendelism illustrating the relations between selection pressure, mutation rates, inbreeding, isolation and the like.

1931 Warder Clyde Allee (1885 - 1955), a Chicago ecologist, publishes his book, Animal Aggregations: A Study in General Sociology. At the time, following the classification of Sciences according to Auguste Comte, many thought that research on animal communities would be relevant to human sociology. This was also an important step in the discussion of commensalism, symbiosis, parasitism and the like. Allee introduces the subject of cooperation in a 'nominalist' way, devoid of moral content, or substantial premisses about the nature of society. According to him, cooperation starts as a mere 'aggregation' of individuals, of protozoa for instance, with the result of enjoying better chances of survival for each. Contrary to Allee, his Chicago colleagues, notably his former teacher Charles M Child (1869 - 1954), held a view in which cooperation was the result of competition, which in turn was constrained by patterns of dominance. Dominance itself was rooted in sexual dominance of the male over the females. Many debates and theory in game theory and in the study of propagation of behaviour in communities rest on work such as that one. It is not indifferent that this debate started in the early thirties, at a time when the idea of struggle for life, competition and degeneracy was beginning to spread throughout the world, culminating in the Nazist view of mankind.

1931 Louis SB Leakey (1903 - 1972) in The Stone Age Cultures of Kenya Colony, begins to dig for decades in the Olduvai Gorge in East Africa. His first major discovery was the jaw of a pre human creature called Proconsul (1948)

1931 At the Karolinska Institute Carl Naeslund (Uppsala 1892 - 1946) tries to persuade medical doctors and dentists of the importance of cleaning teeth, and studies the consequences of using a variety of toothpastes. This is an important step in the improvement of world-wide hygiene.

1931 Fritz Kögl (1897 - 1959), Arie Jan Hagen-Smit (1900 - 1977) and Hanni Erxleben (1903 - 2001) in Holland isolate from human urine and characterize chemically the compound discovered by Fritz Went in 1926 as the compound auxentriolic acid (auxin A) and name it Auxin (after the greek word αυξειν, "increase", "enhance", "grow"). Independently, Kenneth Vivian Thimann (Ashford, England, 1904 - Haverford, Pennsylvania, 1997) purify the substance. Later Kögl isolates other compounds from urine which were similar in structure and function to auxin A, one of which was indole-3 acetic acid (IAA). In 1954 a committee of plant physiologists was set up to characterize the group auxins. Compounds are generally considered auxins if they are synthesized by the plant and are substances which share similar activity to IAA (the first auxin to be isolated from plants).

1931 Joseph Needham (London, 1900 - 1995), best known for his monumental Science and Civilisation in China (Cambridge 1954, seventeen large volumes published, and still being continued), publishes his three-volume Chemical Embryology with an extensive introduction about the history of embryology - his first contribution to the history of science.

1931 Antonio Caetano de Abreu Freire Egas Moniz (Avanca, Portugal, 1874 - 1955) publishes his Diagnostic des tumeurs cérébrales et épreuve de l'encéphalographie artérielle (Diagnostics of cerebral tumours and application of arterial encephalography), in Paris. He later develops brain frontal resection in the treatment of certain psychiatric diseases. This "lobotomy" becomes quite fashionable in the world at a time when the idea of "degeneracy" of individuals and races begins to catch importance.

1931 On the basis of radioactivity and geological data, the age of the Earth is shown to be at least two billion years.

1931-1932 Pierre Teilhard de Chardin (Sarcenat, 1881 - New York,  1955) joins the group sponsored by André Citroën La croisière jaune, to explore the Silk Road from the Western World to China and discover prehistorical remains of humans in China.

1931-1933 Analyzing Tsvett's publication on chromotography, the Austrian biochemist Richard Kuhn (Vienna, Österreich, 1900 - 1967) asks his student Edgar Lederer (1908 - 1988) to adapt the method and refine it for the separation of carotenoids. He discovers a third carotene isomer which is called γ-carotene. Lederer's adaptation of Tsvett's first achievement is particularly successful and they manage to isolate and purify a large number of carotenoids, amongst which astaxanthin (astakoV, lobster in Greek), the pigment that makes lobsters red when they are cooked.

1932 Further working on the role of phosphorylation of small molecules in the management of energy, Lohmann discovers the ATP-phosphocreatine phosphate transfer reaction.

1932 Friedrich Mietzsch (? - ?) and Joseph Klarer (1898 - 1953), from I. G. Farben Industrie, in Germany, synthesize sulfamido-chrysoïdine, a product that was to be the source of the first antibiotics.

1932 Warburg and Walter Christian (? - ?) isolate a yellow conjugated flavoprotein from yeast: the "yellow enzyme" of respiration.

1932 Theodosius Dobzhansky (Nemirov, Russia, 1900 - 1975), Theophilus Painter, and Hermann Muller show that while the linear order of genes is the same for genetic and cytological maps, physical distances and crossover map distances do not coincide. Dobzhansky is best known for his aphorism: "Nothing in biology makes sense except in the light of evolution." Muller shows that without sex mutations will accumulate until they drive extinction (Muller's ratchet).

1932 Haldane publishes his influential book, The Causes of Evolution and an essay on The Origin of Life, where he assumes a heterotroph origin of living organisms.

1932 Further developing his statistical studies of populations, Wright stresses the importance of "genetic drift" due to chance in small populations.

1932 Richard Benedikt Goldschmidt (1878 - 1958) studies adaptation in geographical races of the Gypsy moth (Lymantria dispar). With another species, the Peppered Moth (Biston betularia) he discusses that in industrial areas, melanic forms thrive, while otherwise the moth is white, freckled with black spots. This work was later disputed by special interests groups, but its validity has been established again in 2012. Cook, L. M., B. S. Grant, I. J. Saccheri and J. Mallet. 2012. Selective bird predation on the peppered moth: the last experiment of Michael Majerus. Biology Letters online,:doi: 10.1098/rsbl.2011.1136.

1932 The physiologist Albrecht Bethe (1872 - 1954) introduces the concept of ectohormones, demonstrated in insects, where they may function in trail making, sex attraction, development control, and the like. These substances are known as pheromones. An organism secretes these substances out of the body, where they affect the physiology or behavior of another individual of the same species.

1932 A Danish scientific expedition discovers ichthyostegid fossils in Greenland. These are the oldest known fossils that can be classified as amphibians.

1932 George Edward Lewis (1908 - 1997) finds the first Ramapithecus brevirostris (punjabicus), the earliest known hominid fossil, in the Siwalik Hills of India.

1932 The physicist Niels Bohr (Copenhagen, 1885 - Copenhagen, 1962) begins to be interested in biology and gives a lecture on "Light and Life" at the International Congress of Light Therapy, where he suggests that similar complementarities as those between wave and particle in atom physics might exist in living organisms and may explain the nature of life. While of a completely different nature, this idea of "complementarity" was to have a very important role in the discovery of DNA's structure. The paper is published in 1933: Light and Life, Nature 131: 457-459.

1933 Max Knoll (Wiesbaden, 1897 - 1969) and Ernst August Friedrich Ruska (Heidelberg, Germany, 1906 - Berlin, 1988) build the first electron microscope, that extends considerably the range of observation of biological structures.

1933 Nicolai Vladimirovitch Timofeeff-Ressovsky (Moscow, 1900 - 1981) measures the viability of strains of Drosophila funebris of different geographical origin. Together with Muller, who just came from America to Berlin, they try to prove that not only X-rays but also ultraviolet light can induce mutations. Based on their data the question emerges: "how can the physical nature of light damage chromosomes and genes?" In this context, the physicist and student of Niels Bohr, Max Delbrück (Berlin, 1906 - 1981), enters genetics in Timofeeff-Ressovsky's Institute in Berlin (this Institut is now named after his name: the "Max Delbrück Centrum").

1933 Étienne Camille André (? - ?) demonstrates that soap hydrolysis plays a negative role on teeth and gingivae. This starts research to modify the composition of toothpaste and its action on the microbial flora in the mouth, creating a new domain of microbiology.

1933 Hans Adolf Krebs (Hildesheim, Germany, 1900 - 1981) and Kurt Henseleit (1907 - 1973) establish the first elements of what is now known as the "urea cycle" where synthesis and degradation of the guanidinium, nitrogen-rich group of arginine is explained.

1933 Paul Runar Collander (Finland, 1894 - 1973) and H Bärlund (? - ?) make quantitative measurements of cell membrane permeability chemically the amount of a given substance that appeared in the cell sap of Characean cells a certain time after the cells were placed in a given concentration of the substance to nonelectrolytes of varying molecular size and lipid solubility. Their results contributes enormously to our understanding of membrane structure.

1933 George Wald (New York, 1906 - 1997) discovers vitamin A in the retina.

1933 H Hashimoto (? - ?) describes the chromosomal control of sex determination in the silkworm, Bombyx mori (56 chromosomes) and shows that chromosome W is the sex determining chromosome in the insect.

1933 Gustav Georg Embden (1874 - 1933) and Otto Meyerhof (Hannover, 1884 - 1951) establish the nature of crucial intermediates in the chemical pathway of glycolysis and fermentation. The combination of the work of these authors with that of Lohmann establishes associations between the uptake of phosphate during the breakdown of carbohydrates to lactic acid and the splitting of ATP. They find that ATP is resynthesized in subsequent reactions. This is the first suggestion that the lactic acid cycle participates in the formation of ATP. Despite his work of immense interest Meyerhof had subsequently to leave Nazi Germany, and from 1938 to 1940 he was Director of Research at the Institut de Biologie Physico-Chimique in Paris. In 1940, when the Germans invaded France he had to leave Paris for Toulouse, then for Philadelphia in the United States.

1933 Harry Goldblatt (1891 - 1977) reports that human semen and seminal vesicles contain a factor that reduces blood pressure and regulates smooth muscle activity. This Is the first report that identifies the activity of prostaglandins and prelude to the discovery of renin.

1933 Johannes Friedrich Karl Holtfreter (1901 - 1992) working with amphibian embryos and using a sandwich assay, produces in urodele exogastrulae in which neural tissue does not form, an important tool for understanding embryonic induction.

1933 Heitz and Bauer discover that the giant salivary gland chromosomes of the Diptera are polytene, which allows the banding patterns to be mapped in chromosomes. This facilitates extensive studies on precise gene localization and chromosome structure iscovered that the giant chromosomes

1933-1935 Spemann, Needham (London, 1900 - 1995), Conrad Hal Waddington (1905 - 1975), and others shows that cell-free extracts from the organizer region retains powers of evocation. Chemical studies led to the belief that the evocator was probably a sterol.

1933 Rebecca Craighill Lancefield (1895 - 1981) describes a method of producing streptococcal antigens and sera for use in precipitin tests and suggests that this approach can be used epidemiologically to identify the probable origin of a given strain.

1934 Jacques Duclaux publishes L'analyse chimique des fonctions vitales, a book still full of the vitalism of colloid chemistry.

1934 Ladislaus Laszlo Marton (1901 - 1979) publishes La microscopie électronique des objects biologiques (Electron microscopy of biological objects) in which he is the first to examine biological specimens with the electron microscope, which achieves magnifications of 200-300,000 fold.

1934 Philippe L'Héritier (1906 - 1990) and Georges Teissier (1900 - 1972), with their the "population cage", demonstrate that a deleterious gene disappears from populations of Drosophila melanogaster maintained in population cages for many generations, providing a first example of natural selection in a laboratory setting.

1934 Robert Russell Bensley (1867 - 1956) and Normand Louis Hoerr (1902 - 1958) develop techniques to disassemble cells and isolate cellular components. They isolate and analyze mitochondria.

1934 William Andrew DeMonbreun (1899 - 1968) describes the dimorphic nature of Histoplasma capsulatum after being surprised by the growth of a mold from patient tissues displaying an infection caused by a yeast. He later finds that dogs are natural hosts of this dimorphic fungus. The Dog as a Natural Host of Histoplasma capsulatum: Case of Histoplasmosis in This Animal , Am. J. Trop. Med. 19: 565 (1939).

1934 von Euler notes that Goldblatt has just reported that human semen contains a factor that reduces blood pressure and regulates smooth muscle. von Euler trained with Dale in England had, just a few years earlier, isolated the bioactive peptide compound P. During systematic studies, von Euler finds that extracts of prostate and vesicular glands contain potent blood-pressure-lowering factors from sheep and man that stimulated smooth muscles and were different from compound P. Importantly, von Euler discovers that the activities are of lipidic character and coins the term prostaglandins.

1934 Axel Hugo Theodor Theorell (Linköping, Sweden, 1903 - 1982) demonstrates by using electrophoresis that the lipid-soluble activity (prostaglandins) behave as an acid.

1934 Henrik Dam (Copenhagen, 1895 - Copenhagen, 1976) and Doisy isolate and identifie vitamin K.

1935 Arthur G Tansley (1871 - 1955) coins the word "ecosystem" to define a unit that covers all organisms of a given area as well as their relationship to the inorganic environment. .

1935 Jakub Oskarovich Parnas (Mokriany, then Austro-Hungarian Empire, 1884 - murdered during stalinian purges, 1949) describes for the first time the reactions of glycogen phosphorylation and phosphorylation in glycolysis (at the Institute of Medical Chemistry).

1935 On the initiative of Ludwik Rajchman (1881 - 1965), a world conference on nutrition is convened that establishes for the first time in history a minimal nutritional level necessary for maintaining health in the individual.

1935 Sumner shows experimentally the selective value of protective coloration in fishes.

1935 Sven Otto Hörstadius (1898 - 1996) shows the existence of a double gradient of "animalization" and "vegetalization" in the echinoderm egg.

1935 The work of Gerhard Johannes Paul Domagk (Lagow, Germany, 1895 - 1964) establishes the positive role of sulfamido-chrysoïdine in animal and human streptococcus infections. One of the first patients to be treated with Protonsil was Domagk’s daughter who had a streptococcal infection that was unresponsive to other treatments. When she was near death, she was injected with large quantities of Protonsil and she made a dramatic recovery.

1935 Jacques Trefouël (Le Raincy, France, 1897 - Paris, 1977), Federico Nitti (Ischia, Italia, 1903 - 1947) and Daniel Bovet (Genève, 1907 - Roma, 1992), working in the laboratory of Ernest François Fourneau (Biarritz, 1872 - Paris, 1949), at the Institut Pasteur, conceptualize that in the complex molecule of sulfamido-chrysoïdine with its azoic double bond, only paraminobenzo-sulfonamide (paraminophenylsulfamide) is the active principle. This triggers industrial synthesis of sulfamides and their use as antibacterial agents. The sulfamides Septoplix, Neo-coccyl, Lysococcine, initially experimented in Germany (Prontosil), then in France (Rubiazol) are found highly efficient against meningitis caused by streptococci or pneumococci as well as in the case of blennorragy and colibacillosis, etc.

1935 Percy W Zimmerman (? - ?) and Frank Wilcoxon (1882 - 1965) discover several chemical growth substances which cause initiation of roots and other responses in plants. Wilcoxon is well known for his contributions to statistical tests.

1935 Wendell Meredith Stanley (Ridgeville, Indiana, 1904 - 1971) succeeds in crystallizing tobacco mosaic virus, using the standard techniques for purification of proteins (isoelectric precipitation and salting out with ammonium sulfate) and shows it remains infectious. That a virus could be crystallized caused sensation as it was both a biological and a philosophical breakthrough. However, Stanley does not recognize that the infectious material is nucleic acid and not protein. The fact that he was nevertheless awarded a Nobel Prize (in 1946) shows how strong was the fact that the role of DNA was overlooked for a long time.

1935 Paul Karrer (Moscow, 1889 - Zürich, 1971) and Richard Kuhn (Vienna, 1900 - 1967) identify lactoflavin (riboflavin, or vitamin B2) as the prosthetic group of Warburg and Walter Christian's yellow enzyme.

1935 Szent-Györgyi establishes the involvement of dicarboxylic acids in respiration.

1935 Boris Ephrussi (1901 - 1979) comes to the California Institute of  Technology to work on developmental aspects of genetics did pioneer work on Drosophila eye transplants in 1934 to study genetics with George Wells Beadle (Wahoo, Nebraska, 1903 - 1989), who visited Paris for six months in 1935 to work with him at the Institut de Biologie physico-chimique. Together they began the study of the development of eye pigment in Drosophila, which was the first step of the "one gene - one enzyme" hypothesis.

1935 Robert Runnels Williams (Nellore, India, 1886 - 1965) establishes a correct formula for the structure of vitamin B1 it was named thiamine.

1935 Wald suggests that vitamin A is a precursor of visual purple.

1935 Curtis E Meyer (? - ?) and William Cumming Rose (1887 - 1985) discover threonine, the last essential amino-acid to have been recognized.

1935 Hugh Davson (1909 - 1996) and James Frederic Danielli (1911 - 1984) proposes a "protein-lipid sandwich" model for the structure of cell membranes.

1935 Rudolf Schoenheimer (Berlin, 1898 - committed suicide, 1941) and David Rittenberg (1906 - 1970) first uses isotopes (nitrogen-15 and deuterium) as tracers in the study of intermediate metabolism of carbohydrates and lipids. Schoenheimer had to emigrate to the USA because of the Nazi domination in Germany, in 1933.

1935 Delbrück and Timofeeff-Ressovsky, together with the physicist Karl G Zimmer (1911 - 1988) publish in an article "Über die Natur der Genmutation and der Genstruktur" (On the nature of gene-mutation and gene-structure), their quantum mechanics-oriented results on the stability of genes. Their "Theory of hitting probabilities" shows that the amount of induced mutations must be directly proportional to the applied doses of rays. This allows them to estimate the size of genes, that are supposed to encompass not much more than about 1000 atoms. This, even though it was an underestimation, was a pretty good approximation of real gene sizes. Delbrück proposes that "targets" can induce a mutation as soon as a single electron is expelled by high-energy radiation.

1935-1936 Edward Calvin Kendall (South Norwalk, Connecticut, 1886 - 1972), Philip Showalter Hench (Pittsburgh, Pennsylvania, 1896 - 1965) and, independently, Tadeusz Reichstein (Wloclawek, Poland, 1897 - Basel, Swizerland, 1996) discover cortisone. Kendall had participated in the discovery of thyroxin, the active principle of the thyroid gland, but he is also known for his crystallization of glutathione.

1935-1936 Warburg and von Euler isolate pyrimidine nucleotides and determine their structure and action.

1935-1936 Kurt G Stern (1904 - 1956) observes spectral shifts in catalase as the reaction it catalyzes proceeds, thus demonstrating spectroscopically the existence of an intermediate enzyme-substrate complex for the enzyme catalase, confirming the Michaelis-Menten hypothesis.

1936-1937 John Desmond Bernal (Nenagh, Ireland, 1901 - London, 1971) with Isadore Fankuchen (1904 - 1964) obtains X-ray pictures from the crystals of the 280 nm tobacco mosaic virus particles showing that the "individual rods of tobacco mosaic virus have a regular inner structure of such a nature that each rod could be considered to be a crystal". This was the first hint of the idea of the "aperiodic crystal" that was so successful in the What is life? of Schrödinger later. Bernal demonstrates that isolated preparations of tobacco mosaic virus contain phosphorus as a component of a phospho-ribonucleic acid. They also isolate ribonucleic acids. This challenges the claim by Stanley that the Tobacco Mosaic Virus is composed only of proteins.

1936 Harland Goff Wood (Delavan, Minnesota, 1907 - 1991) and Chester Hamlin Werkman (Fort Wayne, Indiana, 1893 - Ames, Iowa, 1962) discover that plant cells kept in the dark are able to build up larger organic molecules from carbon dioxide. They also show that CO2 is consumed by Propionibacterium arabinosum during the fermentation of glycerol. This is the first report of carbon dioxide fixation by a heterotrophic bacterium.

1936 David Keilin (Moscow, 1887 - Cambridge, 1963) parasitologist and entomologist, isolates cytochrome c (about 80% pure), that he had identified in 1925, and reconstitutes electron transport in particulate heart preparations.

1936 Dorothy Wrinch (Rosario, Argentina, 1895 - 1972) proposes a theory of heredity based on the chaining of the amino-acid residues of proteins, linked by peptide bonds and folded into a cyclic structure. She embarks in model building to substantiate her "cyclol" theory.

1936 John Zachary Young (1907 - 1997) discovers that the squid Loligo contains some enormous nerve cells, including an axon up to 1 mm in diameter and 10 cm long. This allowed scientists to performed studies on the nervous system that, until them, had not been possible.

1936 Louis Rapkine (Tchichenitch, Russia, 1904 - Paris, 1948), who is working at the Institut de Biologie Physico-chimique in Paris on sulfhydryl- groups, creates the Comité français pour l'accueil et l'organisation du travail des savants étrangers to help jewish and antifascist scientists to escape from the Nazis and the fascists.

1936 Pascual Jordan (Hannover 1902 - Hamburg 1980) publishes an intricate article Anschauliche Quantentheorie: Eine Einführung in die moderne Auffassung der Quantenerscheinungen where he tries to justify vitalism via a quantum-based approach. This work is a continuation of a reflection he had previously developed in Die Quantenmechanik und die Grundprobleme der Biologie und Psychologie (1932). Following Bohr, he tries to expand there the quantum concept of complementarity to biology. In his view, complementarity of entities of the same type had a tendency to interact spontaneously. This view which triggered the concept of "self-organization" popular with physicists has been shown to be irrelevant and highly misleading by Delbrück and Pauling in an article published in 1940 where they developed the modern view of structural complementarity based on the chemical shape of biological molecules. Jordan's view about biology is that this science requires a teleological mode of description linked to a necessary holistic view of living organisms. This allows him to justify the role of the observer (a biological entity) in quantum mechanics.

1936 Moniz publishes his Tentatives opératoires dans le traitement de certaines psychoses (Tentative methods in the treatment of certain psychoses) in Paris, followed by La leucotomie préfrontale. A further "demonstration" of the efficacy of lobotomy, Traitement chirurgical de certaines psychoses (Prefrontal leucotomy. Surgical treatment of certain psychoses) is publihed in Torino one year later. This way to consider psychoses is well in line with the general trend of medicine and eugenic practices that are spreading during this dark period of human history.

1936 Needham publishes Order and life, where among other interesting ideas he proposes that the cytoskeleton is a “contractile net”.

1936 Alonzo Church (Washington, DC, 1903 - Hudson, Ohio, 1995) publishes a landmark paper on lambda calculus that shows the existence of an "undecidable problem" in the investigation of recursivity, a property that was later to be found in the way heredity is organised in living systems.

1936 Robert Williams and Kline synthesizes thiamine.

1936 Milislav Demerec (1895 - 1966) and Margaret E Hoover (? - ?) point out the correspondence between giant salivary gland chromosome bands and gene maps. Demerec begins to think about a nomenclature for the description of genes.

1936 Publication of Dobzhansky's Genetics and the Origin of Species.

1936 George Sherman Avery (1903 - 1994) and Paul R Burkholder (1903 - 1972) study the effects of auxins in plant metabolism (publication of Growth hormones in plants).

1936 Alexander Oparin publishes The Origins of Life on Earth, in which he describes hypothetical conditions which would have been necessary for life to first come into existence on early Earth. Life must have come from simple organic molecules present in the early earth's atmosphere. This includes an atmosphere of methane, ammonia, and other gases, much volcanic activity, lightening, and warm soil and water temperatures. This hypothesis was later tested by an experiment done by Stanley Miller with Harold Urey in 1953.

1937 Alan Mathison Turing (London, 1912 - Wilmslow, Cheshire, 1954) invents his Universal Machine, meant to illustrate the concept of algorithm in concrete universal terms. This approach is fundamental in understanding emergent properties of whole numbers, as well as in the concrete construction of computers.

1937 Lohmann and P Schuster isolate the prosthetic group from co-carboxylase and shows that it is the diphosphate of thiamin (vitamin B1).

1937 Hans Adolf Krebs (1900 - 1981) and William Arthur Johnson (1913 - ?) postulate the mechanism of what is now known as the Krebs cycle. Proper names for the cyclic oxidation of substrates in the mitochondria matrix are tricarboxylic acid cycle or citric acid cycle.

1937 Karl Ferdinand Herzfeld (Wien, 1892 - Washington, 1978) who came to America in 1926, publishes articles on a tentative theory of photosynthesis (with J. Franck: An attempted theory of photosynthesis. J. Chem. Phys. 5:237-251).

1937 Thimann suggests that a given concentration of auxin might produce inhibitory effects in one tissue and stimulation in another, different tissues being characterizes by a series of overlapping optimal concentration curves.

1937 Albert Francis Blakeslee (Geneseo, New York, 1874 - 1954) and Amos G Avery (? - ?) use colchicine to produce artificial polyploidy in plant cells.

1937 Marton publishes the first electron micrographs of bacteria.

1937 Edouard Pierre Léon Chatton (1883 - 1947), who mostly worked on protozoa, summarises his past work and separates living organisms into eucaryotes (those with a well formed nucleus; ευ: good, καρυον, kernel, nucleus) and procaryotes (those with no nucleus and the genetic material directly in the cytoplasm of the cell; pro: preceding, or primitive) in a description of the food chain. The spelling used most frequently in English ("karyote") appeared later on. "Les protistologues s'accordent, aujourd'hui, à considérer les Flagellés autotrophes comme les plus primitifs des Protozoaires à noyau vrai, des Eucaryotes (ensemble qui embrasse aussi les Végétaux et les Métazoaires), parce qu'ils sont les seuls pouvoir faire la synthèse totale de leur protoplasme à partir du milieu minéral. Les organismes hétérotrophes sont donc subordonnés à leur existence, ainsi qu'à celle des Procaryotes chimiotrophes et autotrophes (Bactéries nitrifiantes et sulfureuses, Cyanophycées)." Apparently, he was using the terms well before that time (as early as 1925) but did not care to emphasize the importance of the associated concept.

1937 Dobzhansky links evolution and genetic mutations in Genetics and the Origin of Species.

1937 Collander finds that, in general, the more lipophilic a substance is, the greater is its ability to permeate the membrane. However some small hydrophilic molecules, like water also permeate quickly. Collander concludes that while the membrane is made primarily of lipid, it is really a mosaic, and must contain pores to account for the high permeability of some small polar molecules.

1937 René Leriche (Roanne, 1879 - 1955), basing his work on experiments of trauma during the first World War, publishes La chirurgie de la douleur, a book on the importance of physical pain. This work was translated in many languages and makes the basis of new surgical techniques.

1937 Arne Wilhelm Kaurin Tiselius (Stockholm, 1902 - 1971) develops the technique of electrophoresis.

1937 George William Marshall Findlay (1893 - 1952) and MacCullum discover interferon.

1937 Tracy Morton Sonneborn (Baltimore, Maryland, 1905 - Bloomington, Indiana, 1981) lectures at Goucher College on the existence of different mating types in Paramecium.

1937 Frederick Charles Bawden (1908 - 1972) establishes that the tobacco mosaic virus (TMV) contains RNA.

1937-1938 Warburg shows how formation of ATP is coupled to the dehydrogenation of glyceraldehyde 3-phosphate.

1937-1939 Delbrück moves to Morgan's laboratory at Caltech where he gets frustrated by the complex esoteric terminology of Drosophila genetics. With Emory L Ellis (? - ?) he learns about bacteriophages and some fascinating techniques of microbiology. The ease in which one could make viruses visible on a bacterial lawn made experiments possible with an object (phage T4) that for Delbrück was the "atom of biology". With Ellis he establishes the concept of the one-step viral growth cycle for a bacteriophage active against E. coli, published as The growth of bacteriophage. J.Gen.Physiol. 22: 365-384.

1937-1939 Carl Ferdinand Cori (Prague, 1896 - 1984) and Gerty Theresa Radnitz-Cori (Prague, 1896 - 1957) demonstrate the reversible action of glycogen phosphorylase.

1937-1941 Herman Moritz Kalckar (Copenhagen, 1908 - Cambridge, Massachusetts, 1991), and Vladimir Aleksandrovitch Belitser (Riazan 1906 - 1988) and Elena T Tsybakova (? - ?) independently carry out the first quantitative studies of oxidative phosphorylation. Kalckar demonstrates that cell-free extracts of kidney cortex catalyze oxidative phosphorylation - that is, the formation of ATP in reactions strictly dependent on the reduction of oxygen and independent of glycolysis.

1938 Johannes van Overbeek (? - ?) reports that certain nongeotropic mutants in maize do not show the usual inequality of auxin distribution.

1938 Michaelis and MP Schubert (? - ?) propose that free radicals are involved in biochemical reactions: The theory of two-step oxidation involving free radicals. Chem. Rev. 1938, 22, 437-470.

1938 Burrhus Frederick Skinner (Susquehanna, Pennsylvania, 1904 - 1990) invents the "Skinner box", and uses it to investigate operant conditioning in rats (analysis of the couple stimulus / response). With a purely mechanistic view of the mind, he creates a school of psychology known as Behaviorism.

1938 Jean Louis A Brachet (Etterbeek, Belgique, 1909 - 1998) shows that ribonucleic acids are accumulates in regions of high morphogenetic activity.

1938 Alfred Fessard (1900 - 1982), Wilhelm Feldberg (1900 - 1993), and David Nachmansohn (1899 - 1983) establish that the transmission at the electromotor synapse of the electric eel, Torpedo marmorata, is cholinergic and results in the electric discharge of the eel.

1938 Albert Hofmann (Baden, Switzerland, 1906 - 2008) synthesizes the ergotamine molecule, lysergic acid 25 (LSD-25)

1938 Together with Irving Langmuir (New York, 1881 - 1957), Winchher perfects  cage structure theory of proteins (cyclol)  up to a point where she tries to reconcile her hypothesis with X-ray data on insulin. The theory is rapidly discredited, in particular by Pauling.

1938 Field tests of Max Theiler’s vaccine against yellow fever prove successful. The vaccine is based on a mouse passaged virus.

1938 With Kuhn, Franz Moewus (1908 - 1959) develops at the Kaiser-Wilhelm-Institut für Medizinische Forschung in Heidelberg his work on the alga Chlamydomonas eugametos, proposing an elaborate biochemical and genetic interpretation demonstrating that mutants could be isolated and characterized, as well as suggesting cytoplasmic heredity. This work was rapidly clouded by irreproducibility. Speaking of these faked results Haldane reports: "a chap in Berlin who counted different types of algae (or so he said), got such a magnificent agreement between observed and theoretical results, that if every member of the human race had repeated his work once a month for 1012 years, they might expect as good a fit on one occasion (though not with great confidence). So Moewus certainly hadn't done any second order faking. " This work is a famous illustration of an unfortunate practice that plagues studies in biology, especially through publications of faked work in famous journals. Taking on Moewus in 1938, Kuhn was one of the earliest scientists to anticipate the future of molecular genetics. The work became a great personal embarrassment to Kuhn.

1938 Robert (Robin) Hill (Leamington Spa, Warwickshire, 1899 - 1991) finds that cell-free suspensions of chloroplasts evolve oxygen when illuminated in the presence of ferric salts.

1938 Alexander Evseevich Braunstein (Kharkov, 1902 - Moscow, 1986) and MG Kritzman (? - ?), in Soviet Union, discover a new type of reversible enzyme-catalyzed reaction while studying glutamic acid metabolism and transamination reactions.

1938 William Thomas Astbury (Stoke-on-Trent, 1898 - Leeds, 1961) and FO Bell (? - ?) use X-ray diffraction on fibers to analyze the structure of DNA.

1938 Schoenheimer applies radioactive tracers to the study of the biosynthesis of cell structures and concludes that the body is in a state of dynamic equilibrium.

1939 A Coelacanth is caught at the mouth of the Chalumna River, this specimen of a Latimeria, a living crossopterygian fish, is caught off the coast of South Africa. The order Crossopterygii was believed to have died out in the Cretaceous period after it gave rise to the amphibian line.

1939 Gregory Goodwin Pincus (Woodbine, New Jersey, 1903 - 1967) succeeds in inducing parthenogenesis in a mammalian egg. He is best known for the invention of the contraceptive pill.

1939 Sven Otto Hörstadius (1898 - 1996) studies the sea urchin Paracentrotus lividus and differentiates eggs into the categories "regulative" and "mosaic" depending on their pattern of development.

1939 Publication of Everett Ernest Just's (Charleston, South Carolina, 1883 - Washington, DC, 1941) The Biology of the Cell Surface.

1939 Julian Huxley (London, 1887 - London, 1975) introduces the concept of cline in evolutionary variation.

1939 Jeffries Wyman Jr (West Newton, Massachusetts, 1901-1995) publishes An Analysis of the Titration Data of Oxyhemoglobin of the Horse by a Thermal Method, that was to be at the basis of the theory of allostery developed by Jacques Monod and published in 1965 together with Wyman and Changeux.

1939 Samuel Ruben (San Francisco, California, 1913 - died from a laboratory accident, 1943), William Zev Hassid (Jaffa, Palestine, 1899 - 1974) and Martin David Kamen (Toronto, 1913 - 2002) first apply radioactive tracers (carbon-11, the only radioactive tracer available at the time) to the study of photosynthesis. Kamen was later the co-discoverer of the radioactive isotope carbon-14. Kamen suffered shamefully during the anti-Communist witchhunts of the 1940s and 1950s. He recorded his despair in his autobiography, Radiant Science, Dark Politics (1985). His troubles began during the wartime Manhattan atomic bomb project, when in 1943 he was assigned to research at the Oak Ridge National Laboratory, Tennessee.

1939 René Dubos (Saint-Brice-sous-Forêt, 1901 - New York, 1982) discovers that soil bacteria produce chemicals toxic to microbes, Studies on a bactericidal agent extracted from a soil Bacillus J. Exp. Med., 70: 1-17. This reports the discovery of gramicidin and tyrocidin, produced by Bacillus brevis. With Rollin Hotchkiss they file the first patent ever protecting the discovery of an antibiotic. It must be noted that this was the first record of antibiotics produced by Bacilli, and that, for reasons that are not totally clear, the discovery was overlooked. When the genome sequence of Bacillus subtilis was uncovered in 1997, it came out as a surprise that the organism was producing several antibiotics: this would not have been the case if Dubos contribution had received the recognition it deserved.

1939 Georg Borgström (1912 - 1990) finds that shoots exposed to ethylene exhibited positive geotropism associates with the predicted auxin distribution. Ethylene must in some way influence the transverse movement of auxin.

1939 Northrop (New York, 1891 - 1987) publishes Crystalline Enzymes.

1939 Russel E Marker (1902 - 1994) discovers how to transform diosgenin from wild yams into progesterone, synthesizing progesterone in large quantities.

1939-1941 Fritz Albert Lipmann (Königsberg, Preuss, 1899 - Poughkeepsie, New York, 1986) postulates the central role of ATP in the energy transfer cycle. He coins the phrase "energy-rich phosphate bonds".

1939-1942 Engelhardt and Militsa N Lyubimova (? - ?) discover the ATPase activity of myosin, which is therefore an enzyme. The main result of the study is published in Nature in 1939.

1939-1946 Szent-Györgyi discovers actin and actomyosin and describes the role of ATP in muscle contraction.