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Galen of Pergamon describes the human body
Galen was a philosopher, surgeon, and was very smart for his times. He believed that anatomy was fundamental to medicine, since he was not able to dissect humans, he worked on apes and pigs. One of his most important discoveries was that arteries carried blood not air, as was believed for 400 yrs. Though this resulted in many errors as well. https://www.britannica.com/biography/Galen-of-Pergamum -
Lamarck develops Hypothesis of evolution by means of acquired characteristics
Jean-Baptiste Lamarck first presented his Theory of Acquired Characteristics. This basically stated that if an organism changed during its life to adapt to its environments, those changes would be passed off onto its offspring. He also believed that the little toe will eventually disappear, which I hope is not true, because I like my little toe. He greatly influenced the theory of evolution by Charles Darwin. http://necsi.edu/projects/evolution/lamarck/lamarck/lamarck_lamarck.html -
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The Voyage of the HMS Beagle
Darwin, the 22 year old naturalist only spent about 18 months abroad the ship during its 5 year expedition. During the voyage Darwin had written a 770 pg diary, created 1,750 pages of notes and developed 12 catalogs of his 5,436 skins, bones, and carcasses. This voyage inspired many more questions in Darwin which eventually lead to his theory of evolution. https://www.britannica.com/biography/Charles-Darwin/The-Beagle-voyage -
Louis Pasteur refutes spontaneous generation
Spontaneous generation was a theory which stated that life could come from non life. Scientist Louis Pasteur was able to successfully disprove this. His experiment was boiled meat broth, a bent tip in the shape of an S which allowed air in but not airborne organisms. The broth only became foggy with life after he allowed the sterilized broth made contact with the tip of the flask. http://webprojects.oit.ncsu.edu/project/bio183de/Black/cellintro/cellintro_reading/Spontaneous_Generation.html -
The Origin of Species by Means of Natural Selection is published
One of the most influential books of modern times, written by Darwin, an prominent field researcher and scientific writer. He developed his theory for 20 years. Darwin theorized that organisms evolved through a process called natural selection, which radicalized the sciences. Darwin was also greatly influenced by naturalist Jean-Baptiste. https://www.history.com/this-day-in-history/origin-of-species-is-published -
The Germ Theory of Disease is published
Chemist and microbiologist Louis Pasteur proposed the germ theory of disease, which states that certain diseases are caused by specific germs or infectious agents. In the 1800's this was not widely accepted, nor was it the 1st time this idea was thought. Several scientists over 100s of yrs prior observed the same. Pasteur had to work very hard to prove his theory true. Through his experiments, he also disproved spontaneous life.
https://biologywise.com/louis-pasteurs-germ-theory-of-disease -
Gregor Mendel publishes works on inheritance of traits in pea plants
Gregor Mendel first published his theory on genetics in 1866 but it was not widely recognized until the early 1900s. Though his work was with pea plants, his discoveries also applied to human and animal traits as well. One important discovery during this time, was he disproved the widely accepted theory that traits were like a combination of the parents, but with the plants this was not the case. Either they were purple or white, no in between https://www2.palomar.edu/anthro/mendel/mendel_1.htm -
Discovery of the plasmodium falciparum
Charles Louis Alphonse Laveran, an army surgeon, was the first to discover parasites in the blood of his patients infected with malaria. He began searching the elements in Algeria to see if the parasite could be found, such as the dirt and water. After his tests were negative he began to suspect they may be in mosquitoes.He went on to win the Nobel Prized https://www.cdc.gov/malaria/about/history/laveran.html -
Hardy-Weinberg Equilibrium developed.
G.H. Hardy, mathematician and Wilhelm Weinberg, a scientist, developed on their own, basically around the same time, an equation to describe the frequencies of how often dominant and recessive traits will appear in the population. Punnett originally believed that dominant traits would eventually wipe out the recessive ones, but according to this equilibrium, segregation is independent of the segregants. This means A does not happen because of B. http://www.genetics.org/content/179/3/1143 -
T. Hunt Morgan discovers sex-linkage
Morgan was an embryologist turned researcher, who focused on heredity. He breed fruit fly's and one day noticed one of them had white eyes, instead of red. He isolated this fly and breed it, of the 1,000+ offspring he noticed only 3 had white eyes, and they were all male. After several more experiments, he concluded that the white eyes were on the X chromosome, making the first discovery of sex-linked traits. http://www.genomenewsnetwork.org/resources/timeline/1910_Morgan.php -
Neil Bohr develops the Bohr model of atom structure
Bohr discovered that electrons are allowed within a set space around neutrons, not necessarily in a perfect shaped orbit, he also learned that electrons absorb sunlight, giving them energy and making them jump from one level to another. It was basically the start of quantam mechanics. https://www.britannica.com/science/Bohr-atomic-model -
Frederick Griffith describes the process of transformation
Long before the discovery of DNA, Griffith proposed that bacterium could exchange information between each other. He injected 2 types of the Pneumococcus bacteria into mice. when injected with III-S the mice died and with the type II-R they showed few symptoms. He killed the III-S with heat and mixed it with the II-R, and injected this to new mice and the mice all died. This formed a type III-R bacteria, and he called this the transforming principle. https://explorable.com/transforming-principle -
Avery-MacLeod-McCarty determine DNA is the molecule that carries genetic code.
For a very long time scientists believed that genetics was carried in and passed on from proteins in our cells, they believed DNA was too small and simple to carry all that complex information. This team studied the bacteria that carried pneumonia and were able to determine through a series of experiments that DNA carried the genetic information of the bacteria, which was quiet groundbreaking. https://www.yourgenome.org/stories/revealing-dna-as-the-molecule-of-life -
Hershey-Chase experiment
In 1952 these 2 scientists discovered that the DNA is in genetic material, not protein, of the Phage virus. After a phage particle attached to a bacterium, its DNA entered through a tiny hole while the protein coat remained outside. This experiment is often referred to as the blender experiment, since the viral infection was unaffected when in a kitchen blender, removing its empty protein shell from the bacterial wall. https://www.medicinenet.com/script/main/art.asp?articlekey=39044 -
Watson and Crick propose the double helix model of DNA structure
The discovery of the double helix shape of DNA provided ground breaking insights into how proteins are made and the genetic code.Major current advances in science, like fingerprinting and modern forensics and the mapping of the human genome all have their origins in Watson and Crick's work. https://profiles.nlm.nih.gov/SC/Views/Exhibit/narrative/doublehelix.html -
Rosalind Franklin works with DNA and X-Ray crystallography and develops “Image 51”
Rosalind's colleague at Cambridge, gained access to x-ray photos she had taken of the DNA molecule without her knowledge. This colleague then showed the photo to James Watson early that year. Seeing this x-ray photo is what gave him the idea that the DNA strand is a double-helical shape. http://wellcomelibrary.org/collections/digital-collections/makers-of-modern-genetics/digitised-archives/rosalind-franklin/ -
Meselson and Stahl work with DNA replication
At the time of the discovery that DNA replicated itself semi-conservatively, there were 2 other options, conservative and dispersive. Meselson & Stahl conducted an experiment with e-coli bacteria in the hopes of proving the semi-conservative hypothesis true, and they succeeded. This was revolutionary as it lead to us being able to replicate DNA on our own. https://www.khanacademy.org/science/biology/dna-as-the-genetic-material/dna-replication/a/mode-of-dna-replication-meselson-stahl-experiment -
Nirenberg cracks the genetic code
Nirenberg along with his colleague, were able to decipher the first letter in the genetic code, in 1961. Through a series fo experiments they were able to decipher that a single strand of 3 nucleic acids, Uracil, formed the protein phenylalanine. After 7 years of hard work they were able to decipher the rest of the acids, and were awarded the Noble Prize.
https://www.nobelprize.org/educational/medicine/gene-code/history.html -
Endosymbiosis is described by Lynn Margulis
This theory was first proposed by Lynn Margulis in 1967 and published in 1981. The theory states that cells are engulfed, but not digested, living together in a mutually beneficial relationship. When first proposed her theory, and herself were widely ridiculed, but after years of experiments, she was able to build a lot of data to support her theory, and now it is widely accepted. https://www.biology.iupui.edu/biocourses/N100/2k2endosymb.html -
Apollo 11 Lands on Moon
Neil Armstrong, Buzz Aldrin and Michael Collins were the first astronauts to ever walk on the moon. On the morning of 07/16 the Apollo 11 was launched into space. Four days later, they landed on the moon. They spent a few hours exploring the area, collecting samples and also left the American flag, along with a message "Here men from the planet Earth first set foot upon the moon. July 1969 A.D. We came in peace for all mankind." https://www.nasa.gov/mission_pages/apollo/apollo11.html -
The Sanger Technique is developed
He developed a technique, also know as chain termination to sequence DNA. For a very long time this was a simple and easy way to sequence DNA and was very ground breaking. Since then faster methods have been developed but without Sanger technique science would probably be far behind. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4727787/ -
Spliceosomes were discovered and described
The discovery of the spliceosome has helped scientists develop therapeutics that focus on splicing. Diseases have also been discovered that can occur due to the splicing. http://library.cshl.edu/Meetings/mRNA-Splicing/ -
Deep sea hydrothermal vents and associated life around them discovered
Scientists exploring the Galápagos Rift were curious as to why there was such a drastic change in temperatures so deep in the ocean, reaching almost 440 degrees C. Upon further exploration they discovered there were hydro-thermal vents, and organisms thriving there. They learned that these organisms were converting chemicals released by the vents into energy. This redefined our understanding of the requirements for life.
https://www.nationalgeographic.org/media/deep-sea-hydrothermal-vents/ -
Kary Mullis develops Polymerase Chain Reaction
This technique, invented by chemist, Kary Mullis, has revolutionized much of today's research. The technique allows us to make copies of DNA with a really small sample. To name a few, the diagnosis of genetic defects and the detection of the AIDS virus in human cells, as well as link specific persons to samples of blood or hair via DNA comparison.
http://siarchives.si.edu/research/videohistory_catalog9577.html -
The Innocence Project is founded
Founded by Peter Neufeld and Barry Scheck at Cardozo School of Law, this is when wrongly convicted prisoners are proven innocent through DNA. This reformed the justice system to prevent any mishaps like that in the future as well. https://www.innocenceproject.org/about/ -
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CRISPr/CAS 9 is identified and described
Francisco Mojica first hypothesized that this was an adaptive immune system through his studies between 93-05. what this meant was that viruses when met with too much antibiotics can sometimes become more immune to that antibiotic, making it harder to kill. There is a fine line between the right dose to kill the virus, and too much making it stronger. https://www.broadinstitute.org/what-broad/areas-focus/project-spotlight/crispr-timeline -
Dolly the sheep is cloned
Dolly was not the first cloned sheep, there were several before her cloned from embryo cell's. What was different in Dolly's case was the fact that she was cloned from an adult cell. This opened a lot of doors, and made what was believed impossible, possible. She led a normal life, birthing 6 lambs, and after 6 years was put down due to tumors in her lungs. One strange thing was her DNA telomeres were shorter than expected.
http://dolly.roslin.ed.ac.uk/facts/the-life-of-dolly/index.html -
Discovery of the Sahelanthropus Tchadensis fossil
This species is the oldest known in the human family tree and
is believed to have lived between 6 and 7 million years ago in Central Africa.The discovery of this fossil indicated that it is one of the first evidences of evolution from chimpanzee to human. It showed that this species was walking upright and had smaller canine teeth, although it still had a small brain and a few other chimp like features. http://humanorigins.si.edu/evidence/human-fossils/species/sahelanthropus-tchadensis -
Human genome is fully sequenced
"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." This means that in the future doctors/scientists will be able to make more comprehensive and individualized preventative measures for everyone. https://www.genome.gov/11006943/human-genome-project-completion-frequently-asked-questions/ -
Richard L Bible is executed
Richard L Bible was the first person in Arizona to receive conviction with the help of DNA technology. Blood found at the scene of Jennifer Wilson's murder, matched that of the DNA that was found in the stolen Blazer Bible was driving around in after the crime was committed. When this was presented to the jury, the case was essentially closed.
https://www.abc15.com/news/crime/death-row-diaries-the-first-use-of-dna-technology-in-an-arizona-murder-case
