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322 BCE
Aristotle describes like with the Scala Naturae
Aristole was a Greek philosopher and polymath who wrote writings in many diverse subjects. He had a qualitative view of nature. He first detailed classification on living things and systematists. His ideas were based on the scala naturae "Natural Ladder" He divided animals into two types: those with blood and without blood. http://palaeos.com/systematics/greatchainofbeing/scala_naturae.html -
129 BCE
Galen of Pergamon Describes the Human Body
Galen was a Greek who was the Roman Empire's greatest physician. He wrote about 20,000 pages of his work still exists today. He expertise in anatomy, surgery, pharmacology and therapeutic methods. He is famous for bringing philosophy into medicine. http://www.famousscientists.org/galen/ -
Lamarck's Theory of Inheritance of Acquired Characteristics.
[Lamarck based theories acquired Characteristics. He believed that organisms changed over time to fit to their lifestyle. Lamarck thought that elephants used to have short trucks. They would have to stretch their trunks for water and branches which expanded their trunks, passing the trait down to their offspring. He believed that people did not need their little toes and appendix. Eventually it would disappear eventually.(http://necsi.edu/projects/evolution/lamarck/lamarck/lamarck_lamarck.html) -
The Voyage of HMS Beagie
In 1831, Charles Darwin traveled around the world on the HMS Beagle's ship. For five years he explored the coast of South America and the islands, including Galapagos. He filled many notebooks of observations on plants, animals, geology, and collected thousands of specimens which he studied. He concluded that it was by far the most important events in their life. By the time he returned home, he was a well established naturalist. http://www.amnh.org/exhibitions/darwin/a-trip-around-the-world/ -
The Germ Theory of Diseases is published
The germ theory was developed, proved and became popular in Europe and North America between 1850's and 1920's. It encouraged the reduction of diseases between microorganism and hosts. Louis Pasteur was a chemist who wanted to understand the species of bacteria and which ones can be used for vaccinations. He wanted to investigate further on unseen disease-causing organisms and where they come from. https://bigpictureeducation.com/history-germ-theory -
The Orgin of Species by Means of Natural Selection
Charles Darwin published this book. By 1872, he had 6 more edition. From then it because a very popular book. The book talked about evolving of a variety of species, adaptations, variation in physical appearance. He argued how traits are passed from parents to offspring. He mentioned a number of ways that illustrates how species survive in their natural environment. He stated his hypothesizes on the limitations and growth on species. http://www.sparknotes.com/lit/origin/summary.html -
Louis Pasteur Refutes Spontaneous Generation
Louis Pasteur designed an experiment to test whether sterile nutrient broth could generate microbial life. He set up 2 separate experiments. Adding nutrient broth to each flask. One of the set ups was exposed to air from above where as test 2 was left alone. The results are that test 1 created microbial life. http://www.pasteurbrewing.com/louis-pasteur-experiment-refute-spontaneous-generation/ -
Gregor Mendel works on inheritance of traits in pea plants
When Gregor Mendel worked on his pea plant experiment he then discovered the fundamental laws of inheritance. He concluded that genes come in pairs and were inherited as distinct units from each of the parent. He decoded the mathematical patters from one generation to the next. He then started "Mendel's Laws of Heredity" Law of Segregation, Law of Independent Assortment, and Law of Dominance. http://www.dnaftb.org/1/bio.html -
Alfred Russel Wallace Ideas of Evolutionary Processes
When Thomas Malthus published a book in 1979 called Essay on the Principle of Population. Darwin and Wallace believed that both plants and animals should have the same experience of population pressure. They realized that if an animal has some traits help withstand the elements or the breed more successfully, it may leave more offspring behind than others. http://evolution.berkeley.edu/evolibrary/article/history_14 -
The Challenger Oceanography Expediton Sails Around the Word
Modern oceanography began with the Challenger Expedition between 1872 and 1876. It was the first expedition organized to gather data on a wide range of ocean features, ocean temperatures seawater chemistry, currents, marine life, and the geology of the seafloor. A British Navy corvette was converted into the first dedicated oceanographic ship with its own laboratories, microscopes and other scientific equipment onboard. http://www.divediscover.whoi.edu/history-ocean/challenger.html -
Hardy and Weinberg Equation for Determining Allele Frequencies In Populations
Determining the frequency of dominant and recessive alleles in populations give the frequency of the phenotypes.. In the early 20h century Hardy and Weinberg developed a model describing the relationship between the dominant and recessive alleles in a population. In order for alleles to be unchanged from each generation conditions had to be met. -
Jacques Cousteau develops SCUBA
Cousteau's interest in the sea began as a child. He would swim to the bottom of the pools an lakes and practiced holding his breath under water. Once he got older he enlisted into the military and explored the sea, but wanted to know what was underneath. He then started inventing a device to allow this teaming up with French engineer Emile Gagnan. Dr.Christian Lambertsen designed an apparatus for the U.S military in 1939 called SCUBA. http://www.waterencyclopedia.com/Ce-Cr/Cousteau-Jacques.html -
Thomas Hunt Morgan Sex-Linked
In 1910, geneticist Thomas Morgan observed a fruit fly with a different eye color than usual. Curious he began an experiment of transmission of genetic traits. Through successive generations he developed a simple breeding analysis. While conducting his experiment he discovered and confirmed the chromosome theory. http://www.nature.com/scitable/topicpage/thomas-hunt-morgan-and-sex-linkage-452 -
Neil Bohr develops the Bor model of Atom Structure
In 1913 Bohr described his discovery on how shell model of an atom to explain how electrons can have a stable orbits around the nucleus. Bohr modified Rutherford's model by requiring that electrons move in orbits of fixed size and energy. The energy of an electron depends on the size of the orbit and is lower for smaller orbits. He addressed that radiation can only occur when electron jumps from one orbit to another. http://abyss.uoregon.edu/~js/glossary/bohr_atom.html -
Griffith Describes the Process of Transformation
Griffith believed that information could be transferred between different strains of bacteria. He developed an experiment by using two different types of bacteria type lll-5 and type ll-R. Only difference was that type ll-5 strain has a sooth polysaccharide coat which makes it easy to resistant to the immune system of mice. The results came that type lll-5 been transformed into type lll-R strain. Becoming the transforming principle. https://explorable.com/transforming-principle -
Plasmodium Falciparum is Described as the Causative Agent of Malaria
Four host-restricted or adapted species of Plasmodium are traditionally recognized as responsible of human malaria. Occasionally, human beings can be infected either naturally or accidentally by several simian species. The life cycle of all species of human malaria parasites is characterized by an exogenous sexual phase in which multiplication occurs in several species. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3340990/ -
Dobzhansky Genetics and the Orgin of Species
Theodosius Dobzhansky was a book popularized by population of genetics to other biologists. He influenced their appreciation for genetic basis of evolution. He applied Sewall Wright's studies of natural population. He implements theories of mutation, natural selection, and speciation. He explains his theories in depth as a process over time on life on earth. https://en.wikipedia.org/wiki/Genetics_and_the_Origin_of_Species -
Barbara McClintock Describes Transposons
In the late 1940s, Barbara McClintock challenged existing concepts of what genes were capable of when she discovered that some genes could be mobile. Her studies of chromosome breakage in maize led her to discover a chromosome-breaking locus that could change its position within a chromosome. McClintock went on to discover other such mobile elements, now known as transposons. http://www.pnas.org/content/109/50/20198.full -
Beadle and Tatum 1 Gene- 1 Enzyme Hypothesis
One gene- one enzyme hypothesis was proposed by George Beadle in 1941. The theory was that each gene produces a single enzyme, which affects an individual step in a metabolic pathway. He used fruit flies in his experiment. Beadle and Tatum created Neurospora mutants by irradiation Neurospora with x-rays. They worked with each other to determine how exactly genes regulated enzymes and controlled biochemical reactions. https://embryo.asu.edu/pages/george-w-beadles-one-gene-one-enzyme-hypothesis -
Ernst Mayr Developed the Biological Species Concept
The biological species concepts give understanding and explanation of how certain species biological species can breed together. Although they cannot breed with other group of species. This would mean that they would be reproductively isolated from other groups. Ernst Mayr had believed that when existing species split, new species form. http://www.pnas.org/content/102/suppl_1/6600.full -
Avery, MacLoed, McCarty Determine the Genetic Coding
Although Watson and Crick developed the Double Helix of the DNA, Avery, MacLeod and McCarty belived that the proteins carried out the geetic information. The scientist followed the Griffith experiment but they tweaked it a bit in their own way. They found out that the "transforming agent" was the protein. -
Frosalind Franklin DNA and Z-Ray Crystallography and Develops Image 51
Franklin was an expert in a powerful technique for determining the structure of molecules know as X-Ray crystallography. He crystallized a molecule such as DNA to be exposed to X-rays to deflect by the atoms in the crystal. This gave clues about the molecule structure. Image 51 was a remarkable clear and X-ray diffraction image of DNA produced by Franklin. https://www.khanacademy.org/science/biology/dna-as-the-genetic-material/dna-discovery-and-structure/a/discovery-of-the-structure-of-dna -
Ensatina described as a ring species
Estatina's theory was based on a ring-like distribution of the different forms of species. It started off in Northern California, Oregon and migrated south along each side of the Central Valley. He based his idea on morphology of the subspecies, looking for different color patterns. He noticed species that where near each other were similar to one another verses species that were further away seemed to blend into one another. http://evolution.berkeley.edu/evolibrary/article/0_0_0/devitt_02 -
Hershey-Chase experiments are published
A legendary experiment that helped to convince the word that DNA was in fact a genetic material. The phage virus contains phage genes. After the particle attaches to a bacterium, its DNA enters through a tiny hole while its protein coat remains outside. Its whole purpose was to show that the viral infection was unaffected by violent agitation. It became known as the "blender experiment". Hershey and Chase won a Nobel Prize for this.http://www.medicinenet.com/script/main/art.asp?articlekey=39044 -
Watson and Crick Double Helix Model of DNA Structure
Francis Crick and James Watson both presented the structure of the DNA Helix. They created a model of a molecule that carried genetic information down to each generation. Many scientist had failed to figure out the biological riddle and Crick and Watson were the first ones do decode it. They received a Nobel Prize in Physiology or Medicine in 1962. http://www.nobelprize.org/educational/medicine/dna_double_helix/readmore.html -
Miller-Urey experiement
In 1952 Harold Urey carried out an experiment to see if the early atmosphere was reducing. In conclusion he found out that main constituents were CH4, NH3,H2, and H2O. In 1953 his student Stanley Miller attempt the experiment. His results were that most of the ammonia and methane had been generously consumed. The main gasesous produced where Nitrogen and Carbon Monoxide.
http://www.simsoup.info/Origin_Landmarks_Miller_Urey.html -
Meselson and Stahl Work With DNA Replication
Meselson and Stahl distinguish existing DNA from new DNA and to track new and old DNA over several rounds of replication. Labeling cells with different stable isotopes of nitrogen. First, a culture of bacterial cell were grown for several generations in.These cells were put into a media containing only the more common, lighter isotope of nitrogen 14N. http://scienceprimer.com/meselson_stahl_experiment -
Endosymbiosis Is Described by Lynn Margulis
In the late 1960's Margulis studied the structure of the cells. To her they looked like bacteria. She spent much time in the 1960's arguing her belief but it was still unrecognized. In the 1970's she published her argument in The Origin of Eukaryotic Cells. http://evolution.berkeley.edu/evolibrary/article/history_24 -
Nirenberg Cracks the Genetic Code
1n 1961 a biochemist named Marshall Nirenberg from National Institute of Arthritic and Metabolic Diseases discovered the first "triplet" sequences of the three bases of DNA that codes from one of the 20 amino acids that proteins use as building blocks. Within 5 years after the first triplet was decoded he then figured out the who genetic code sequences for the triplet codon base pairs. http://www.genomenewsnetwork.org/resources/timeline/1961_Nirenberg.php -
Spliceosome Descovered and Described
The U snRNAs were originally discovered as small uridine-rich RNA molecules present in mammalian nuclei, and they were initially numbered in order of their apparent abundance. U1, U2, U4, U5, U6, U11, and U12 were later found to be spliceosome components. U7 snRNA is required for histone mRNA 3′-end processing; the other abundant U snRNAs (U3, U8, U9 and U10) are all involved in ribosome biogenesis. http://www.sciencedirect.com/science/article/pii/S096098221401553X -
Apollo 11 lands on the moon
NASA sent out astronauts Neil Armstrong, Buzz Aldrin and Michael Collins out in space. They landed on the moon. At approximately 10: 56pm EDT Neil Armstrong was the first human ever to step on the moon. Aldrin joined him afterward. They left an American flag and patch honoring the fallen Apollo 1 crew and plaque that states, "Here men from 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 -
Nothing in Biology Makes Sense Except in the Light of Evolution
Theodosius Dobzhansky believed that evolution is the cornerstone of biology. His quote in his essay “nothing in biology makes sense except in the light of evolution” quote has been used in numerous articles. He talked about the central importance of "evolution" in a basic understanding for the natural world. https://answersingenesis.org/theory-of-evolution/nothing-in-biology-makes-sense-except-in-the-light-of-evolution-myth-evalutation/ -
"Lucy" Fossil Discovered
Australopithicus afarensis nicknamed "lucy" was a pair of fossils that was discovered in Hadar in Ethiopia by Tom Grey and Donald Johanson. They believed that the specie lived between 3.9 to 2.8 million years ago. The specie is one of the best known of our ancestor due to a number of discoveries including a set of fossil footprints and fairly complete fossil skeleton which was "lucy". https://iho.asu.edu/about/lucys-story#third -
Deep Sea Hydrothermal Vents
In 1997, scientist were exploring the Galapagos Rift. Along the mid ocean ridge they noticed serious temperature spikes in their data in such short difference. Studying it more, they soon discovered that the ocean has deep sea hydrothermal vents. Lack of sunlight, toxic minerals and pressure characterized the deep sea vent ecosystem. http://nationalgeographic.org/media/deep-sea-hydrothermal-vents/ -
The Sanger Technique Is Developed
The method of sequencing the genetic code was descovered by Fred Sanger. To sequence the DNA, it had to be separated into 2 strands. These altered bases cause the copying process to stop each time one particular letter is incorporated into the building the DNA chain. This process is carried out for all four bases, and then the fragments are put together like a puzzle to reveal the sequence of the original piece of DNA https://unlockinglifescode.org/timeline/11 -
Kary Mullis Develops Polymerase Chain Reaction
Kary Mullis invented the PCR in 1985 while working as a chemist. It requires placing a small amount of the DNA containing the gene into a test tube. A large batch of loose nucleotides exact copies of the original gene, is also added to the tube. A pair of DNA segments match segments on each side of the desired gene, is added. These "primers" find the right portion of the DNA, and serve as starting points for DNA copying. http://siarchives.si.edu/research/videohistory_catalog9577.html -
Tommie Lee Andrews Is Convicted of Rape
Tommie Lee Andrews was a serial rapist who was the first person ever to get convicted of his charges using DNA evidence. He served 62 years in prison. He was scheduled to be released December 30th, 2010 from good behavior. http://articles.orlandosentinel.com/2012-08-03/news/os-dna-tommie-lee-andrews-release-20120803_1_serial-rapist-tommie-lee-andrews-dna-evidence -
Reproductive isolation as a consequence of adaptive divergence in Drosophila pseudoobscrura"
The idea was to analyze the homogamy detection between two natural populations of Drosophila melanogaster from Brazzaville. It conducted the experiment on the Isolation and pre-mating isolation of these species. It looked on behalf of the mating choice, post-mating, pre-mating and dominance between male species. http://link.springer.com/article/10.1023%2FA%3A1021288527291 -
The human genome
Is a great exploration in history. It is the discovery and map of all the genes, known as the genome. It speaks on behalf of the homosapien species. It is practically the genetic blue print of the human being. IIt was the determination of nucleotide base pairing that makes up human DNA. in 1984 the US government launched the experimentations in 1990. It is a 13 year long project. https://www.genome.gov/10001772/#al-2 -
Innocence Project
The innocence project was founded in 1992 by Peter Neufeld and Barry Scheck at Cardozo School of Law. The goal was to use DNA testing into the criminal justice system to prove innocence of people who were incarcerated for unjust imprisonment. This could conduct a test to prove if a person is guilty or not just by taking a DNA test. http://www.innocenceproject.org/about/ -
Dolly The Sheep Is Cloned
She was cloned at the Roslin Institute in Midlothian Scotland. She lived there until her death of was six years old.Her birth was announced on February 22, 1997. The sheep was originally code-named "6LL3".The name "Dolly" came from a suggestion by the stockmen who helped with her birth, in honor of Dolly Parton, because it was a mammary cell that was cloned. The technique that was made famous by her birth is somatic cell nuclear transfer. https://www.sciencedaily.com/terms/dolly_the_sheep.htm -
Sahelanthropus tchadensis fossil discovered
The oldest known species in the human family tree. They lived sometime between 6 to 7 million years ago in the West-Central Africa. The skull is proven evidence that the species had small brains and sloping faces, similar to a chimpanzee. The size of the skull suggested that it was a male. He had small flat canine teeth that is usual for a primate. They were to believe to walk upright and believed to have 2 legs. http://humanorigins.si.edu/evidence/human-fossils/species/sahelanthropus-tchadensis -
CRISPR-CAS9
CRISPR-CAS9 is a genome editing tool. It is a faster and cheaper accurate technique of editing DNA and has a wide range of potential applications. It removes, adds, or alters sections of DNA sequence. It introduces a change into the DNA by an enzyme called Cas9. A piece of RNA binds to DNA and pre designed sequence Cas9 to the right part of the genome. It comes from strep bacteria that is actually a naturally occurring, defense mechanism. http://www.yourgenome.org/facts/what-is-crispr-cas9 -
Homo Denisova Fossil Discovered
Researchers say Devonians existed thousands of years alongside modern humans and Neanderthals. They believed Neandetal relatives may have migrated along the southern Siberia for 60,000 years ago. The only evidence they had was a finger bone found in the Siberia's Altai Mountains. Years after, teeth were found in the same cave. http://www.dailymail.co.uk/sciencetech/article-3321354/The-mysterious-cousin-lived-alongside-Neanderthals-Homo-sapiens-DNA-shows-Denisovans-far-widespread-thought.html -
Richard L Bible is executed
This was a case that happened in Flagstaff AZ. In 1988, Jennifer Wilson was on vacation with her family. She decided to ride her bike a few miles back to the ranch, but never showed up. Bible age 26, was arrested seven hours later after the disappearance of Jennifer was convicted of murder due to the DNA found in his truck and on his clothing. Two decades later he was executed with a lethal injection. http://archive.azcentral.com/news/articles/20110630arizona-execution-richard-lynn-bible.html
