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160 BCE
Galen of Pergamon describes the human body
Galen 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. Galen put forward the theory that illness was caused by an imbalance of the four humors blood, phlegm, black bile and yellow bile. He recommended specific diets to help in the "cleansing of the putrefied juices" and often purging and bloodletting would be used. -
Lamarck develops Hypothesis of evolution by means of acquired characteristics
Mr. Lamarck is known for his Theory of Inheritance of Acquired Characteristics. He said that change is made by what the organisms want or need. An example is Mr. Lamarck believed that elephants all used to have short trunks. He also believed that when elephants did have food or water they stretch there trunk and that's how there offspring inherit long trunks. Lamarck also believed that evolution happens according to a predetermined plan and that the results have already been decided. -
Alfred Russel Wallace published ideas of evolutionary processes
Alfred Russel helped discover Evolution. He then played a pivotal role in developing the theory of natural selection. He was also one of the nineteenth century's leading of naturalists and explorers. But over time, Charles Darwin became almost universally thought of as the father of evolution. -
The Voyage of the HMS Beagle
The voyage of HMS Beagle was the second survey expedition of HMS Beagle to under captain Robert FitzRoy who had taken over the command of the ship on its first voyage. Mr. FitzRoy had already thought of the advantages of having an expert in geology on board, and sought a gentleman naturalist as a supernumerary who could be his companion while the ship was at sea. -
Louis Pasteur refutes spontaneous generation
Louis Pasteur designed an experiment to test whether sterile nutrient broth could spontaneously generate microbial life. He then had to set up two experiments which Mr. Pasteur added nutrient broth to a flasks, bent the necks of the flasks into S shapes, and then boiled the broth to kill any existing microbes. Mr.Pasteur's Problem, Where do the microbes come from to cause broth to decay? His Hypothesis: Microbes come from cells of organisms on dust particles in the air; not the air itself. -
The Origin of species by means of Natural Selection is published
Charles Darwin published a book called "On the Origin of Species by Means of Natural Selection". It is about the preservation of favored races in the struggle for Life. Mr. Darwin wrote that Natural Selection shouldn't be aloud because they the people should be able to make a decision on whether they want to buy something instead of the government making all there decisions. -
Gregor Mendel publishes works on inheritance of traits in pea plants
Gregor Mendel was known as the "father of modern genetics." Through his work was on pea plants. He discovered the fundamental laws of inheritance. He then deduced that genes to come in pairs and to be inherited as distinct units, one from each parent. Mendel then tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits. -
The Germ Theory of Disease is published
The germ theory of disease was the biggest achievement of the French, scientist Louis Pasteur. He was one of the scientist to propose that diseases that were caused by microscopic organisms, but then they were view as controversial in the 19th century, and opposed the theory of “spontaneous generation”. -
Hardy and Weinberg independently develop the Hardy-Weinberg equation for determining
The Hardy-Weinberg equation is the mathematical equation that can be used to calculate the genetic variation of a population at equilibrium. Hardy and Wilhelm Weinberg independently described a basic principle of population genetics, which is now named the Hardy-Weinberg equation. -
Neils Bohr develops the Bohr model of atom structure
Neils Bohr proposed his 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, was Bohr modified the Rutherford model by requiring that the electrons to move in orbits of fixed size and energy. -
T. Hunt Morgan discovers sex-linkage
T. Morgan and his colleagues published “The Mechanism of Mendelian Heredity.”They were the ones who study major tenets which were ‘certain characteristics that are sex-linked—that is. It occur together because they arise on the same chromosome that determines gender. -
Frederick Griffith describes the process of transformation
In this critical experiment, Frederick Griffith mixed some heat-killed S with live R and injected the combination into mice, which kill them. 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. -
Beadle and Tatum publish the 1 gene-1 enzyme hypothesis
The concept was proposed by George Beadle and Edward Tatum in an influential a paper on genetic mutations in the mold Neurospora crassa. The subsequently was dubbed the "one gene–one enzyme hypothesis" by their collaborator Norman Horowitz. -
Jacques Cousteau develops SCUBA
Jacques Cousteau and his partner Emilie Gagnan were the ones to invented the scuba gear. They helped divers finally explore parts of the ocean they had never seen before. Mr. Cousteau and his Gagnan co-invented a demand valve system that would supply divers with compressed air when they breathed. There modern demand was named Aqua-Lung and there invention eventually opened the door to diving for anyone who was interested. -
Ernst Mayr develops the Biological Species Concept
Ernst Mayr was one of the evolutionary biologists who approached Charles Darwin’s species problem with a new definition for species in his book “Systematics and the Origin of Species.” He also wrote the species that are 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
Avery, Colin MacLeod, and Maclyn McCarty demonstrate a report about DNA being a substance that causes bacterial transformation, in the era that it has been widely believed that it was proteins that served the function of carrying genetic. -
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. Her work, transpositions are now a hot favorite among biologists in the field of gene manipulation. Her studies of chromosome breakage in maize led her to discover a chromosome-breaking locus that could change its position within a chromosome. -
Rosalind Franklin works with DNA and X-Ray crystallography and develops “Image 51”
Rosalind Franklin's was mostly famous for her piece of evidence that she found, 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. This structure consists of two helices (corkscrew structures) running in parallel. -
Hershey-Chase experiments are published
The Hershey–Chase experiments were a series of experiments conducted by Alfred Hershey and Martha Chase. They helped confirm that DNA is genetic material. Their experiments showed bacteriophages, which are composed of DNA and protein, infect bacteria. Although the results were not conclusive, there experiment was cautious in their interpretation, previous, contemporaneous, and subsequent discoveries all served to prove that DNA is the hereditary material. -
Miller-Urey experiments published
The Miller-Urey experiment was preformed by Stanley Miller and Harold Urey who carried out some experiments.They then published their results in 1953. There aim was to see if any substances now made by living things could be formed in the conditions thought to have existed on the early Earth. -
Watson and Crick propose the double helix model of DNA structure
Watson and Crick took a crucial conceptual step, suggesting that molecules were made out of two chains of nucleotide, each in a helix. Then they showed that each strand of the DNA molecule was a template for the other. They showed the structure of DNA by using stick-and-ball models to test their ideas on the possible structure of DNA. -
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. Which supported the hypothesis that DNA replication was semiconservative. In the semiconservative hypothesis, proposed by Watson and Crick, the two strands of a DNA molecule separate during replication. Each strand then acts as a template for synthesis of a new strand. -
Nirenberg cracks the genetic code
Marshall Nirenberg and his colleagues focused on how DNA directs protein synthesis. They also foucsedon the role of RNA in these processes. Their experiment, was using a synthetic messenger RNA (mRNA) strand that contained only uracils which yielded a little protein that contained only phenylalanines. -
Endosymbiosis is described by Lynn Margulis
Margulis, a prolific writer and dynamic speaker, who wrote her first article on the endosymbiotic theory in 1967. It then brought her to the forefront of the controversy over cellular evolution. American biologist whose serial endosymbiotic theory of eukaryotic cell development revolutionized the modern concept of how life arose on Earth. -
Kary Mullis develops Polymerase Chain Reaction
Kary Mullis 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. Kary Mullis talks about his discovery of the polymerase chain reaction (PCR), a process that allows chemists to produce many copies of a specific fragment of DNA. He succeeded in demonstrating PCR. -
Theodosius Dobzhansky “Nothing in Science Makes Sense Except in the Light of Evolution.”
Russian population geneticist name Theodosius Dobzhansky, who lived from 1900 to 1975. He published so many books during the years. -
Australopithicus afarensis nicknamed “lucy” fossil discovered
Lucy the fossil was discovered in Africa near the village Hadar in the Awash Valley of the Afar Triangle in Ethiopia. Lucy was found by a paleoanthropologist name Donald Johanson of the Cleveland Museum of Natural History. The Lucy specimen is an early Australopithecus who is dated to about 3.2 million years ago. -
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. It assembled from snRNAs and protein complexes. The Max Planck Institute for Biophysical Chemistry in Göttingen and at Freie Universität Berlin have jointly discovered the mechanism by which this regulation takes place. -
The Sanger Technique is developed
Frederick Sanger developed the classical “rapid DNA sequencing” technique, now known as the sanger method. He was determine to find the order of the bases in a strand of DNA. He then noted the key role that special enzymes and that plays in this process, used to synthesize short pieces of DNA. -
Deep sea hydrothermal vents and associated life around them are discovered
The 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. Most of the sulfur comes from the Earth's interior a small portion is produced by chemical reaction of the sulfate present in the sea water. -
Richard L Bible is executed
Richard Lynn an Arizona executed 49-year-old a 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. -
Tommie Lee Andrews is convicted of rape
Through DNA fingerprints, a jury found Tommie Lee 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. An expert in genetics analysis had testified that the DNA ''fingerprint'' of Tommy Lee Andrews' blood matched the rapist's semen. -
The Innocence Project is founded
The Innocence Project was found as a non-profit legal organization that committed to exonerating wrongly convicted people through the use of DNA-testing. They also said they would reform 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. He worked on them throughout the 1990’s and in 2000, he recognized that what had been reported as disparate repeat sequences, was just (he coined the term CRISPr through correspondence with Ruud Jansen. -
Dolly the sheep is cloned
Dolly was the first 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. She was cloned at the Roslin Institute in Midlothian, Scotland, and lived there until her death when she was six years old. -
Sahelanthropus tchadensis fossil discovered
A Sahelanthropus is claimed as one of the most significant discoveries in the field of human evolution, the fossils represent the oldest known human ancestor of the split of the human line from chimpanzees. Sahelanthropus are nine cranial specimens from northern Chad. A research team of scientists led by French paleontologist name Michael Brunet, which he uncovered the fossils in 2001, including the type specimen. -
Human genome is fully sequenced
The Human Genome is a international scientific research project that will be determining the sequence of nucleotide based on pairs that make up human DNA. Identifying and mapping all of the genes in a human genome from both a physical and a functional standpoint. A standpoint is the position from which someone is able to view a scene or an object. -
Homo denisova fossil discovered
Scientists announced the discovery of a finger bone fragment of a juvenile female who lived about 41,000 years ago. They found her in the remote Denisova Cave in the Altai Mountains in Siberia .After that they found that Unlike the mtDNA results, the nuclear DNA results showed that the Denisova individual were more closely related to Neandertals than to modern humans. Evidences suggesting that the Denisovan and Neandertal lineages had separate histories once they diverged. -
Theodosius Dobzhansky publishes Genetics and the Origin of Species
The resolution was called "evolutionary synthesis" a modern synthesis and one of its architects was Russian population geneticist Theodosius Dobzhansky. What is modern evolutionary is the physical and behavioral changes that make natural selection and it happens at the level of DNA and genes. Such changes are called mutations. Mr. Dobzhansky quote "Nothing in Biology Makes Sense Except in the Light of Evolution."
