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1864 BCE
Louis Pasteur refutes spontaneous generation
Louis Pasteur designed an experiment to test whether sterile nutrient broth could spontaneously generate microbial life. To do this, he set up two experiments. In both, Pasteur added nutrient broth to flasks, bent the necks of the flasks into S shapes, and then boiled the broth to kill any existing microbes. -
460 BCE
The Germ Theory of Disease is published
The germ theory of disease states that many diseases are caused by microorganisms. These small organisms, too small to see without magnification, invade humans, animals, and other living hosts. ... Microorganisms that cause disease are called pathogens, and the diseases they cause are called infectious diseases. -
160 BCE
Galen of Pergamon describes the human body
He was a prominent Greek physician, surgeon, and philosopher in the Roman Empire. He was the first of the great anatomists (AD 130-200), first performing anatomy on Barbary apes.
Works cited: Web; www.brainblogger.com/2011/08/20. -
Lamarck develops Hypothesis of evolution by means of acquired characteristics
Lamarck, proposed ideas about evolution involving the concept, and even Charles Darwin, after Lamarck, developed his own theory of inheritance of acquired characters, pangenesis. The basic concept of inheritance of acquired characters was finally widely rejected in the early 20th century. -
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The Voyage of the HMS Beagle
On the morning of 27 December 1831, H.M.S. Beagle, with a crew of seventy-three men, sailed out of Plymouth harbor.Darwin made his first curious discovery. He found a horizontal white band of shells within a cliff face along the shoreline of Porto Praya.
Narrative of the Surveying Voyages of His Majesty's Ships Adventure and Beagle between the years 1826 and 1836, Volume 2, page 43. FitzRoy, Capt. Robert. New York: AMS Press, 1966. -
Alfred Russel Wallace published ideas of evolutionary processes
Alfred Russel Wallace was one of the nineteenth century's leading naturalists and explorers. He co-discovered with Charles Darwin the theory of evolution by natural selection, and he is one of the founders of the modern field of biogeography. -
The Origin of species by means of Natural Selection is published
On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life), published on 24 November 1859, is a work of scientific literature by Charles Darwin which is considered to be the foundation of evolutionary biology. -
Gregor Mendel publishes works on inheritance of traits in pea plants
Gregor Mendel, through his work on pea plants, discovered the fundamental laws of inheritance. He deduced that genes come in pairs and are inherited as distinct units, one from each parent. Mendel tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits. -
Hardy and Weinberg independently develop the Hardy-Weinberg equation for determining allele frequencies in populations
The Hardy-Weinberg equation is the mathematical equation that can be used to calculate the genetic variation of a population at equilibrium. In 1908, G.H. Hardy and Wilhelm Weinberg independently described a basic principle of population genetics, which is now named the Hardy-Weinberg equation. Works cited: Web; www.nature.com -
Neils Bohr develops the Bohr model of atom structure
Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus. This was a stability problem, so the remedy to the problem, Bohr modified the Rutherford model by requiring that the electrons move in orbits of fixed size and energy -
T. Hunt Morgan discovers sex-linkage
In 1915, Morgan and his colleagues published “The Mechanism of Mendelian Heredity.” And one of its major tenets was, ‘certain characteristics are sex-linked—that is … occur together because they arise on the same chromosome that determines gender. Works cited: web; www.genomenewsnetwork.org -
Frederick Griffith describes the process of transformation
In the critical experiment, Frederick Griffith (1928) mixed heat-killed S with live R and injected the combination into mice: the mouse died. The dead mouse’s tissues were found to contain live bacteria with smooth coats like S. These bacteria were subsequently able to kill other mice, and continued to do so after several generations in culture. He concluded that something in the heat-killed S bacteria “transformed.” Works cited: web; www.mun.ca/biology.org -
Theodosius Dobzhansky publishes Genetics and the Origin of Species
Genetics and the Origin of Species is a 1937 book by the Ukrainian-American evolutionary biologist Theodosius Dobzhansky. It is regarded as one of the most important works of the modern evolutionary synthesis. -
Beadle and Tatum publish the 1 gene-1 enzyme hypothesis
The concept was proposed by George Beadle and Edward Tatum in an influential 1941 paper on genetic mutations in the mold Neurospora crassa, and subsequently was dubbed the "one gene–one enzyme hypothesis" by their collaborator Norman Horowitz. -
Jacques Cousteau develops SCUBA
In 1942, Cousteau and Gagnan co-invented a demand valve system that would supply divers with compressed air when they breathed. This modern demand regulator was named Aqua-Lung and its invention eventually opened the door to diving for anyone who was interested. "Jacques Cousteau - The Father of Scuba Diving." RSS. N.p., n.d. Web. 30 Apr. 2017. -
Ernst Mayr develops the Biological Species Concept
He was an evolutionary biologists who approached Charles Darwin’s species problem with a new definition for species in his book “Systematics and the Origin of Species” (1942 and he wrote that a species is not just a group of morphologically similar individuals, but a group that can breed only among themselves, excluding others. -
Avery, MacLoed and McCarty determine that DNA is the molecule that carries the genetic code
In 1944, Oswald Avery, Colin MacLeod and Maclyn McCarty helped demonstrate the role of DNA as the carrier of genetic information by working with the bacterium? that causes pneumonia?, Streptococcus? pneumonia. -
Barbara McClintock describes transposons
She was an American scientist and cytogeneticist who discovered transposition and used it to demonstrate that genes are responsible for turning physical characteristics on and off. Because of her work, transposons are now a hot favorite among biologists in the field of gene mainipulation. -
Rosalind Franklin works with DNA and X-Ray crystallography and develops “Image 51”
Rosalind Franklin's most famous piece of evidence is this image: Photo 51. It depicts an X-ray diffraction of DNA. Taken in 1951, the image eventually led to the conclusion that DNA was composed of a double helix. -
Hershey-Chase experiments are published
The Hershey–Chase experiments were a series of experiments conducted in 1952 by Alfred Hershey and Martha Chase that helped to confirm that DNA is genetic material. -
Miller-Urey experiments published
The Miller–Urey experiment was a chemical experiment that simulated the conditions thought at the time to be present on the early Earth, and tested the chemical origin of life under those conditions. -
Watson and Crick propose the double helix model of DNA structure
The discovery in 1953 of the double helix, the twisted-ladder structure of deoxyribonucleic acid (DNA), by James Watson and Francis Crick marked a milestone in the history of science and gave rise to modern molecular biology, which is largely concerned with understanding how genes control the chemical processes within cells. -
Meselson and Stahl work with DNA replication
This was an experiment by matthew Meselson and Canadian biologist, Mason McDonald, and Canadian nuclear physicist, Amandeep Sehmbi, in 1958 which supported the hypothesis that DNA replication was semiconservative. (when the double stranded DNA helix is replicated, each of the two new double-stranded DNA helices consisted of one strand from the original helix and one newly synthesized. -
Nirenberg cracks the genetic code
Marshall Nirenberg and his colleagues focused on how DNA directs protein synthesis and the role of RNA in these processes. Their 1961 experiment, using a synthetic messenger RNA (mRNA) strand that contained only uracils (U), yielded a protein that contained only phenylalanines. -
Endosymbiosis is described by Lynn Margulis
Margulis, a prolific writer and dynamic speaker, wrote her first article on the endosymbiotic theory in 1967, brought her to the forefront of the controversy over cellular evolution. Works Cited: Web; www.msu.edu -
Theodosius Dobzhansky publishes “Nothing in Science Makes Sense Except in the Light of Evolution.”
He was an Ukrainian-American geneticist and evolutionist whose work had a major influence on 20th century thought and research on genetics and evolutionary theory. He wrote this essay in 1973, criticizing anti-evolution creationism and espousing theistic evolution. -
Australopithicus afarensis nicknamed “lucy” fossil discovered
Lucy was found by Donald Johanson and Tom Gray on the November 24, 1974, at the site of Hadar in Ethiopia. -
The Sanger Technique is developed
In 1977, Frederick Sanger developed the classical “rapid DNA sequencing” technique, now known as the sanger method, to determine the order of the bases in a strand of DNA. He noted the key role that special enzymes play in this process, used to synthesize short pieces of DNA. -
Deep sea hydrothermal vents and associated life around them are discovered
In 1977, scientists exploring the Galapagos Rift along the mid-ocean ridge in the eastern Pacific noticed a series of temperature spikes in their data. They wondered how deep-ocean temperatures could change so drastically-from near freezing 400 degrees C (750 degrees F) in such a short distance. This discovery was – deep-sea hydrothermal vents. Works Cited: www.Nationalgeographic.org -
Kary Mullis develops Polymerase Chain Reaction
He was a Nobel Prize-winning American biochemist, author, and lecturer. Mullis was driving his vehicle late one night with his girlfriend, who was also a chemist at Cetus, when he had the idea to use a pair of primers to bracket the desired DNA sequence and copy it using DNA polymerase. He succeeded in demonstrating PCR December 16, 1983. -
Tommie Lee Andrews is convicted of rape
Through DNA fingerprints, a jury found Andrews guilty as a convicted serial rapist. This case is significant because this case ended with the first American trial to admit DNA typing into evidence.
Works Cited: Web; www.prezi.com -
Richard L Bible is executed
Arizona executed 49-year-old Richard Lynn Bible for molesting and fatally bludgeoning 9-year-old Jennifer Wilson in 1988. He asked the U.S. Supreme Court to delay his execution for DNA testing on hairs used as evidence in his trial. -
The Innocence Project is founded
This is a non-profit legal organization that is committed to exonerating wrongly convicted people through the use of DNA-testing and to reforming the criminal justice system to prevent future injustice. It was founded in 1992 by Barry Scheck and Peter Neufeld. -
CRISPr/CAS 9 is identified and described
Francisco Mojca was the first researcher to characterize what is now called CRISPr locus, reported in 1993. He worked on them throughout the 1990’s and in 2000, he recognized that what had been reported as disparate repeat sequences, (he coined the term CRISPr through correspondence with Ruud Jansen. Works Cited: web; www.broad.institue.org -
Dolly the sheep is cloned
Dolly was a female domestic sheep, and the first mammal cloned from an adult somatic cell, using the process of nuclear transfer. She was born on 5, July 1996 and had three mothers. (one provided the egg, another the DNA and a third carried the cloned embryo to term.) -
Sahelanthropus tchadensis fossil discovered
The first fossils of Sahelanthropus are nine cranial specimens from northern Chad. A research team of scientists led by French paleontologist Michael Brunet uncovered the fossils in 2001, including the type specimen TM 266-01-0606-1. Smithsonian's National Museum of Natural History. Sahelanthropus Tchadensis | The Smithsonian Institution's Human Origins Program. N.p., 01 Mar. 2010. Web. 30 Apr. 2017. -
Human Genome
On April 14, 2003 the National Human Genome Research Institute (NHGRI), the Department of Energy (DOE) and their partners in the International Human Genome Sequencing Consortium announced the successful completion of the Human Genome Project. "Human Genome Project Completion: Frequently Asked Questions." National Human Genome Research Institute (NHGRI). N.p., n.d. Web. 30 Apr. 2017. -
Homo denisova fossil discovered
In 2008, a small fossil finger bone was found at the Denisova Cave in the Altai mountains in southern Siberia. -
Spliceosomes were discovered and described
A spliceosome is a large and complex molecular machine found primarily within the splicing speckles of the cell nucleus of eukaryotic cells. The spliceosome is assembled from snRNAs and protein complexes.
