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Galen of Pergamon describes the human body
Galen often believed that anatomy was the "foundation of medical knowledge". His beliefs were inspired by many other scientists, with his research be had predicted that the body consisted of 3 main connective systems: the brain, heart and liver. This is what his main achievements and understandings were based on. https://www.britannica.com/biography/Galen-of-Pergamum -
Lamarck develops Hypothesis of evolution by means of acquired characteristics
According to Lamarck organisms change overtime in order to adapt to their environment. He was the first to develop this hypothesis which was later on expanded upon by Charles Darwin. http://necsi.edu/projects/evolution/lamarck/lamarck/lamarck_lamarck. -
The voyage of the HMS beagle
In 1831 Charles Darwin agreed to go on a voyage around the world on a ship named the HMS Beagle. Over the 5 year course Darwin had observed many animals, plants, and geology when he visited many Islands including the Galapagos. Throughout the years this voyage shaped Darwin to the man he was and allowed him to come up with the Theories we know today. https://www.amnh.org/exhibitions/darwin/a-trip-around-the-world/ -
The Origin of Species by means of Natural Selection
On this day Charles Darwin published The Origin of Species by means of Natural Selection. In this he stated that all organisms evolve overtime by the process called "natural selection". This process states that organisms that are best suited for their specific environment tend to survive and pass their trait to their offspring. While the organisms that are less adapted to their environment tend to fail at surviving. https://www.history.com/this-day-in-history/origin-of-species-is-published-2 -
Louis Pasteur refutes spontaneous generation
Spontaneous Generation was the belief on how life came to be. It explained that life came from anything, even air. Louis Pasteur on the other hand did not agree with this belief. He created an experiment using sterile broth to test the fact that it cannot be contaminated with bacteria with air alone. With these results he came to the conclusion that "life comes from life". https://www.zmescience.com/other/feature-post/louis-pasteur-spontaneous-generation-germ-theory/ -
Gregor Mendel publishes works on inheritance of traits in pea pants
Mendel's work on pea plants has led him to discover different laws of inheritance. There are 3 main laws: The law of Segregation, The law of Independent Assortment, and The law of Dominance. Mendel used over 10,000 pea plants which recorded their progress, this took around 8 years until he a enough evidence to publish his work. http://www.dnaftb.org/1/bio.html -
The Germ Theory of disease
The Germ Theory states that diseases are caused by the actions and presence infectious agents or germs found inside a body. This theory was first proposed by Louis Pasteur around the 1800's which was not accepted by many. With his continuous experiments he proved his theory correct and it was only around the 1860's. This revolutionized the study of diseases and modern medicine. https://biologywise.com/louis-pasteurs-germ-theory-of-disease -
Plasmodium Falciparum is described as the causative agent of malaria
Plasmodium Falciparum is also known as protozoan parasite which is a main cause of malaria. Malaria is often caused by an infection of protozoa which is transferred by mosquitos. There have been many advances in medicine which allow people to not contract malaria, such as drugs and vaccines. Without these medical advances many people mostly in Africa could potentially die form malaria. http://scientistsagainstmalaria.net/parasite/plasmodium-falciparum -
Hardy and Weinberg independently develop the Hardy-Weinberg equation for determining allele frequencies in populations
In 1908 Hardy and Weinberg had developed an equation that would help understand Mendel's genetics in context of population. This is used to measure whether the observed genotype frequencies in a population differ from the frequencies from the equation. They developed the equation p2 + 2pq + q2 = 1 where p represents a dominant allele and q represents a recessive allele. While 1 is the sum of frequencies of both alleles which is 100% http://www.genetics.org/content/179/3/1143 -
T. Hunt Morgan discovers sex-linkage
in 1907 T. Hunt Morgan a embryologist began to breed fruit flies to see if a mutation or a new offspring would be created. With these experiments he has discovered that female flies had XX chromosome and males have XY chromosomes.
http://www.genomenewsnetwork.org/resources/timeline/1910_Morgan.php -
Niels Bohr develops the Bohr model of atom structure
In 1913 Niels Bohr had produced his atomic model which explained how electrons could have a stable orbit while still orbiting the nucleus. Bohr had explained that the energy of the electron depended on the size of the orbit. Bohr knew that electrons could jump from one orbit to another by emitting or absorbing energy. http://abyss.uoregon.edu/~js/glossary/bohr_atom.html -
Frederick Griffith describes the process of transformation
In 1928 Frederick Griffith had done an experiment to where he tested with two strains of Pneumococcus bacteria type III-S and type II-R. He then would inject these into mice and see the results of what would happen to the mice. During the last of his experiments he noticed that the type III-S strain had transformed into an type III-R strain. https://explorable.com/transforming-principle -
Avery, MacLeod and McCarty determine that DNA is the molecule that carries the genetic code
in 1944 Avery, MacLeod, and McCarty demonstrated the role of DNA as the main carrier of genetic information by using bacterium that causes pneumonia. They experimented on S bacteria proving that a transforming principle must be DNA. https://www.yourgenome.org/stories/revealing-dna-as-the-molecule-of-life -
Hershey-Chase experiments are published
Hershey believed that DNA was the carrier of all genetic information. His experiment was based on using DNA- specific and protein-specific labels which show the viruses DNA entering the bacterium. The protein in the cell would then be striped by the waring blender. http://www.genetics.org/content/149/1/1 -
Rosalind Franklin works with DNA and X-Ray crystallography and develops "Image 51"
In 1952, Rosalind Franklin has developed a clearer x-ray called the B-form which uses water in a DNA sample. When researching with her Gosling about how humidity affects images she had taken many photos and used X-ray Crystallography allowed to take a clear image of a molecules atom to create a 3D structure. When using this she discovered an X in the x-ray which later inspired Crick and Watson to create their double helix. https://www.insight.mrc.ac.uk/2013/04/25/behind-the-picture-photo-51/ -
Watson and Crick propose the double helix model of DNA structure
DNA was first identified by Friedrich Miescher around the late 1860's, over the years it was improved on by other scientists such as Erwin Chargaff. After many years Watson and Crick concluded that the DNA molecule is in the form of a three-dimensional double helix. They had suggested that the DNA molecule was made up of two strands and with this they created their model using Chargaff's rule. https://www.nature.com/scitable/topicpage/discovery-of-dna-structure-and-function-watson-397 -
Meselson and Stahl work with DNA replication
While Crick and Watson had discovered a DNA structure, Meselson and Stahl had begun to discover DNA replication. They have made many observations while trying to understand a way to create an experiment. They had decided to change one of the parent DNA's atoms and used the isotope to see the difference between the parent DNA and copied DNA.
https://www.nature.com/scitable/nated/article?action=showContentInPopup&contentPK=421 -
Nirenberg cracks the genetic code
In 1961 Nirenberg had discovered that a sequence of 3 bases of DNA served as the building blocks of protein. He has observed that more than one codon could stand for a certain amino acid. As well as that each codon consisted of 3 bases in a specific order or when presented with 4 bases it would be 64 triplets. With this he then discovered that 3 of the codons signaled the end of the amino acid. http://www.genomenewsnetwork.org/resources/timeline/1961_Nirenberg.php -
Endosymbiosis is described by Lynn Margulis
Margulis first proposed the Symbiotic Theory where she believed that organelles were bacteria that had their own DNA. Her theory was proved correct in 1980's when two organelles were found to have DNA that resembles bacterial DNA. She published her work in 1981 even though many did not approve her theory, over the years her believes became well known and helped many other scientists. https://www.biology.iupui.edu/biocourses/N100/2k2endosymb.html -
Apollo 11 moon landing
July 16, 1969 at 9:32 am Apollo 11 fires away in the route to the moon. They leave the tower and after 12 minutes are in Earths orbit. In the ship, astronauts Neil Armstrong, Buzz Aldrin, and Charles Duke communicate with NASA throughout their journey. After three days in space with only 30 seconds of fuel left Apollo 11 successfully lands on the moon on the day of July 20, 1969 at 4:18 pm. With this came an ongoing travel to the unknown. https://www.nasa.gov/mission_pages/apollo/apollo11.html -
Deep sea hydrothermal vents and associated life around them are discovered
In 1977 while exploring the Galapagos Islands a group of scientist had first discovered a hydrothermal vent in the deep sea. While having a closer look they found that there were many organisms found around the vent which have not yet been seen. They have concluded that hydrothermal vents occur when seawater goes down the ocean crust then is heated by magma which results in it reemerging through the vents. https://oceanservice.noaa.gov/facts/vents.html -
Spliceosomes were discovered and described
In 1977 mRNA splicing was discovered that established a new way for genetic information to "flow" from DNA to RNA to the protein product. Splicing is the process where mRNA is edited and copied from the nuclear DNA to a mature mRNA molecule. This process helps with many different diseases such as muscle degenerative diseases and even cancer. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3119917/ -
The Sanger Technique is developed
Fredrick Sanger was the first to develop the Rapid DNA Sequencing other known as the Sanger Technique in 1977. He was able to determine the order of bases found in a strand of DNA. With this method it helped scientists read sequences of nucleotides in a DNA sequence. https://unlockinglifescode.org/timeline/11 -
Kary Mullis develops Polymerase Chain Reaction
In 1983 Kary Mullis had developed the Polymerase Chain Reaction (PCR) while trying to increase the demand of oligonucleotides. He believed that PCR is using DNA to synthesize a new strand of DNA that is complementary to the template strand. http://www.karymullis.com/pcr.shtml -
The innocence Project is founded
This project was founded in 1992 in New York City to help prisoners who could be proven innocent with DNA testing be freed. This project has helped many prisoners prove there innocence including 17 of the 273 who were in death row. This DNA technology has helped many people who were convicted to be criminals become free after proving their innocence. http://www.myphilanthropedia.org/top-nonprofits/national/criminal-justice/2011/the-innocence-project -
CRISPr/CAS 9 is identified and described
The function of CRISPr/CAS are essential in creating immunity to certain bacteria allowing them to respond to and eliminate invading genetic material. They rely on an enzyme and a guide molecule which allows them to modify the gene. This allows organisms to defend themselves when they are presented with a dangerous virus. https://www.neb.com/tools-and-resources/feature-articles/crispr-cas9-and-targeted-genome-editing-a-new-era-in-molecular-biology -
Dolly the sheep is cloned
Dolly was a Finn Dorset sheep whom existence was going to be used for an amazing cause. On February 5, 1996 Dolly was submitted to be the first mammal to be cloned from an adult cell. Her survival was a great example to many that adult cells can reprogram into new cells. She also proved that clones can also reproduce successfully throughout their lifetime. http://novaonline.nvcc.edu/eli/evans/HIS135/events/dolly96/Dolly_Module.html -
Sahelanthropus Tchadensis fossil discovered
In 2001 a group of researchers discovered a fossil that could be lead to ancestral remains of humans and apes. This was a huge discovery since it allowed scientists to see the transition from chimpanzees to humans. This cranial discovery was found in Africa, where 9 more were found. http://humanorigins.si.edu/evidence/human-fossils/species/sahelanthropus-tchadensis -
Human genome is fully sequenced
On April 14, 2003 it was officially announced that the Human Genome was fully sequenced. A genome is the complete set of deoxyribonucleic acid or DNA of an organism which directs and developed every organisms activity. Once sequenced it means that the exact order of the base pairs are determined. There are some portions of the sequencing that cannot be fully recovered but most of it is complete. https://www.genome.gov/11006943/human-genome-project-completion-frequently-asked-questions/ -
Richard L Bible is executed
On June 30, 2011 Richard L Bible was killed by lethal injection after the death of Jenifer Wilson. Bible was convicted of the rape and murder of 9-year-old Jenifer. After 23 years he was finally killed by the state of Arizona. https://deathpenaltynews.blogspot.com/2011/06/arizona-executes-richard-lynn-bible.html
