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150 BCE
Galen of Pergamon describes the human body
Galen learned the nervous system, heart and breathing by dissecting Barbary apes since dissecting humans was forbidden. He considered the apes the closest animal to the human form. His work on anatomy became influential over the next 1,400 years.
Source:http://brainblogger.com/2011/08/20/human-dissection-from-galen-to-the-great-revelations-of-andreas-vesalius/ -
Lamarck develops Hypothesis of evolution by means of acquired characteristics
Lamarck stated that changes made for an organism to adapt to their environment are passed on to their children. The change was influenced by the organisms want or need. He used the example of elephants having short trunks. If there wasn't food or water the elephants would stretch their trunks out thus giving their offspring longer trunks.
Source:http://necsi.edu/projects/evolution/lamarck/lamarck/lamarck_lamarck.html -
The Voyage of the HMS Beagle
The HMS Beagle left Plymouth on December 26 and went to the Madeira, Canary, and Cape Verde islands. Darwin took notes on the animals he saw during the trip. One was cuttlefish that changed colors he found around he island's tide pools.
Source:https://www.google.com/search?q=Miller-Urey+experiments+published&source=lnms&sa=X&ved=0ahUKEwialsO8luHTAhVG9GMKHYBUBv8Q_AUICSgA&biw=1440&bih=705&dpr=1#q=what+was+The+Voyage+of+the+HMS+Beagle -
Alfred Russel Wallace published ideas of evolutionary processes
Alfred Russel Wallace and Charles Darwin were inspired by Thomas Malthus who published a book titled Essay on the Principle of Population. The book warned people that population growth would become a problem in the future. They thought about Malthus' idea but in the form of plants and animals instead of people and concluded that since the planet hasn't been overrun by them that it cannot happen with humans either.
Source:http://evolution.berkeley.edu/evolibrary/article/history_14 -
The Origin of species by means of Natural Selection is published
This book had 6 editions by the year 1872. He wrote these after traveling on the HMS Beagle in South America and the Galapagos Islands for 5 years. He developed his theory in secret for 20 years before publishing his findings.
Source:http://www.history.com/this-day-in-history/origin-of-species-is-published -
Louis Pasteur refutes spontaneous generation
Louis Pasteur made the flask with a curved neck to trap microorganisms without allowing them to contaminate what was in the bottle of the flask. He broke the neck of the flask a year later and proved life could only come from other life when the microorganisms appeared.
Source:https://amoebamike.wordpress.com/2009/10/06/spontaneous-generation-a-brief-history-of-disproving-it/ -
Gregor Mendel publishes works on inheritance of traits in pea plants
Gregor Mendel proved that traits can appear in offspring without mixing parental traits by cross breeding pea plants. He also discovered genes passed on from parents are unchanged, offspring inherits one unit from each parent, and a trait may now show in one generation but can in the next which we now know as the principle of segregation and the principle of independent assortment.
Source:http://anthro.palomar.edu/mendel/mendel_1.htm -
The Germ Theory of Disease is published
Germ theory is the theory that diseases are caused by microorganisms. The organisms grow and reproduce inside a host causing disease.
Source:https://en.wikipedia.org/wiki/Germ_theory_of_disease -
Hardy and Weinberg independently develop the Hardy-Weinberg equation for determining allele frequencies in populations
Godfrey Hardy and Wilhelm Weinberg gave evolution the definition of the change of of alleles in the gene pool of a population. They discovered evolution could not happen without mutation, natural selection, a large population, members of the population breeding, random mating, the same number of offspring being made, and no migration within a population. They developed the equation by comparing genotype frequencies within generations.
Source:http://anthro.palomar.edu/synthetic/synth_2.htm -
T. Hunt Morgan discovers sex-linkage
T. Hunt Morgan discovered sex-linkage when he was breeding fruit flies in his lab and one had white eyes. He discovered all of the white eyes fruit flies were male. The white eyed gene was inherited by the Y gene. He discovered that half of the next generation of males would inherit the white eye gene.
Source:http://www.genomenewsnetwork.org/resources/timeline/1910_Morgan.php -
Jacques Cousteau develops SCUBA
Jacques Cousteau was an underwater researcher and photographer. During WWII he went to the town Megreve with his family and built his first aqua lung device. He went on an underwater expedition in the Mediterranean Sea in 1948 to find the shipwreck Mahdia, which became the first underwater operation using diving equipment.
Source:http://www.biography.com/people/jacques-cousteau-9259496 -
Neils Bohr develops the Bohr model of atom structure
The Bohr model was made up of 4 principles. The electron's stationary orbit around the nucleus, each orbit is controlled by energy, when the electron moves from a higher orbit to a lower orbit light is emitted and when it moves from a lower orbit to a higher orbit light is absorbed, and light absorbed or emitted is from the difference between the 2 energies.
Source:http://www.iun.edu/~cpanhd/C101webnotes/modern-atomic-theory/Bohr-model.html -
Frederick Griffith describes the process of transformation
Frederick Griffith injected rats with Pneumococcus type III-S and II-R for his experiment. The rats exposed to III-S and heat died but the ones that stayed away from the heat lived. When the mice were injected with both the nonlethal III-S passed transformed unto the II-R.
Source:https://explorable.com/transforming-principle -
Theodosius Dobzhansky publishes Genetics and the Origin of Species
Genetics and the Origin of Species influenced the genetic basis of evolution. The book talks about the diversity and evolution of animals.
Source:https://en.wikipedia.org/wiki/Genetics_and_the_Origin_of_Species -
Beadle and Tatum publish the 1 gene-1 enzyme hypothesis
The one gene on enzyme theory states each gene produces 1 enzyme. He demonstrated this theory with fruit flies.
Source:https://embryo.asu.edu/pages/george-w-beadles-one-gene-one-enzyme-hypothesis -
Avery, MacLoed and McCarty determine that DNA is the molecule that carries the genetic code
Avery Macleod and Maclyn McCarthy worked with bacteria that causes pneumonia to demonstrate DNA's role.
Source:http://www.yourgenome.org/stories/revealing-dna-as-the-molecule-of-life -
Barbara McClintock describes transposons
Barbara McClintock was interested in the behavior of chromosomes without telomeres and studied chromosome breaking locus and discovered transposition.
Source:https://www.osti.gov/accomplishments/mcclintock.html -
Rosalind Franklin works with DNA and X-Ray crystallography and develops “Image 51”
This image led to the discover of DNA's double helix.
Source:http://www.brighthub.com/science/genetics/articles/76072.aspx
