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384 BCE
Aristotle describes life with the Scala Naturae
• He classified animals by their way of life, their actions, or by their parts
•described the embryological development of a chick; the chambered stomachs of ruminants and the social organization of bees;
•Aristotle was the first to give the first detailed classification of living things, and hence the first systematists. He did not classify plants or fungi,
• Blooded and Viviparous quadrupeds (land mammals)
http://palaeos.com/systematics/greatchainofbeing/scala_naturae.html -
129 BCE
36. Galen of Pergamon describes the human body
Galen regarded anatomy as the foundation of medical knowledge, and he frequently dissected and experimented on such lower animals as the Barbary ape (or African monkey), pigs, sheep, and goats. Galen’s advocacy of dissection, both to improve surgical skills and for research purposes, formed part of his self-promotion, but there is no doubt that he was an accurate observer.
https://www.britannica.com/biography/Galen-of-Pergamum -
Lamarck develops Hypothesis of evolution by means of acquired characteristics
- Lamarck is best known for his Theory of Inheritance of Acquired Characteristics, first presented in 1801
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Alfred Russel Wallace published ideas of evolutionary processes
Alfred Russel Wallace known for his courageous views on scientific, social, and spiritualist subjects. His formulation of the theory of evolution by natural selection, which predated Charles Darwin’s published contributions, is his most outstanding legacy, but it was just one of many controversial issues he studied and wrote about during his lifetime. Wallace’s wide-ranging interests—from socialism to spiritualism, from island bio geography to life on Mars. -
The Voyage of the HMS Beagle
In 1831, when Darwin was just 22 years old, he set sail on a scientific expedition on a ship called the HMS Beagle. He was the naturalist on the voyage. As a naturalist, it was his job to observe and collect specimens of plants, animals, rocks, and fossils wherever the expedition went ashore -
The Germ Theory of Disease is published
The germ theory of disease states that many diseases are caused by microorganisms. These small organisms, too small to see without magnification, invade humans, animals, and other living hosts.
germ theory was proposed by Girolamo Fracastoro in 1546, and expanded upon by Marcus von Plenciz in 1762.
A transitional period began in the late 1850s with the work of Louis Pasteur -
Louis Pasteur refutes spontaneous generation
Louis Pasteur designed an experiment to test whether sterile nutrient broth could spontaneously generate microbial life. To do this, he set up two experiments. In both, Pasteur added nutrient broth to flasks, bent the necks of the flasks into S shapes, and then boiled the broth to kill any existing microbes. -
Gregor Mendel publishes works on inheritance of traits in pea plants
Discovered the fundamental laws of inheritance. He deduced that genes come in pairs and are inherited as distinct units, one from each parent. Mendel tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits. He recognized the mathematical patterns of inheritance from one generation to the next. Mendel's Laws of Heredity are usually stated as
1) The Law of Segregation
2) The Law of Independent Assortment
3) The Law of Dominance -
The Origin of species by means of Natural Selection is published
Natural Selection, a groundbreaking scientific work by British naturalist Charles Darwin, is published in England. Darwin’s theory argued that organisms gradually evolve through a process he called “natural selection.” In natural selection, organisms with genetic variations that suit their environment tend to propagate more descendants than organisms of the same species that lack the variation, thus influencing the overall genetic makeup of the species. -
The Challenger Oceanography Expedition sails around the world
The Challenger expedition of 1872–76 was a scientific exercise that made many discoveries to lay the foundation of oceanography. The expedition was named after the mother vessel, HMS Challenger. ... Theexpedition, led by Captain George Nares, sailed from Portsmouth, England, on 21 December 1872. -
Plasmodium falciparum is described as the causative agent of malaria
Plasmodium falciparum is a unicelluar protozoan parasite of humans, and the deadliest species of Plasmodium that cause malaria in humans.[2] It is transmitted through the bite of a female Anopheles mosquito. It is responsible for roughly 50% of all malaria case https://en.wikipedia.org/wiki/Plasmodium_falciparum -
T. Hunt Morgan discovers sex-linkage
• These results were suggestive for hypotheses of which Morgan himself was skeptical. He was at the time critical of the Mendelian theory of inheritance, mistrusted aspects of chromosomal theory, and did not believe that Darwin's concept of natural selection could account for the emergence of new species
• http://www.genomenewsnetwork.org/resources/timeline/1910_Morgan.php -
T. Hunt Morgan discovers sex-linkage
• These results were suggestive for hypotheses of which Morgan himself was skeptical. He was at the time critical of the Mendelian theory of inheritance, mistrusted aspects of chromosomal theory, and did not believe that Darwin's concept of natural selection could account for the emergence of new species
• http://www.genomenewsnetwork.org/resources/timeline/1910_Morgan.php -
Hardy and Weinberg independently develop the Hardy-Weinberg equation for determining allele frequencies in populations
The Hardy-Weinberg equilibrium is the fundamental concept in population genetics (the study of genetics in a defined group). It is a mathematical equation describing the distribution and expression of alleles (forms of a gene) in a population, and it expresses the conditions under which allele frequencies are expected to change. Mathematically, since p + q 1 , (p + q) 2 must also equal 1 -
Neils Bohr develops the Bohr model of atom structure
In atomic physics, the Rutherford–Bohr model or Bohr model or Bohr diagram, introduced by Niels Bohr and Ernest Rutherford in 1913, depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus—similar to structure of the Solar System. -
Avery, MacLoed and McCarty determine that DNA is the molecule that carries the genetic code
The Avery–MacLeod–McCarty experiment was an experimental demonstration, reported in 1944 by Oswald Avery, Colin MacLeod, and Maclyn McCarty, that DNA is the substance that causes bacterial transformation, in an era when it had been widely believed that it was proteins that served the function of carrying genetic information. -
Frederick Griffith describes the process of transformation
Griffith's experiment, was an experiment done in 1928 byFrederick Griffith. It was one of the first experiments showing that bacteria can get DNA through a processcalled transformation. ... These bacteria infect mice. He used a type III-S (smooth) and type II-R (rough) strain. -
Hershey-Chase experiments are published
• The Hershey–Chase experiments were a series of experiments conducted in 1952 by Alfred Hershey and Martha Chase that helped to confirm that DNA is genetic material https://en.wikipedia.org/wiki/Hershey%E2%80%93Chase_experiment -
Jacques Cousteau develops SCUBA
• Jacques Cousteau is one of the leading person in developing the aqua lung which is very important for diving deep in to underwater.
• https://www.deepblu.com/post/81641b20107c11e7aa9ad181bc785596 -
Ensatina described as a ring species
• In 1949, Robert Stebbins
• Ensatina eschscholtzii has been described as a ring species in the mountains surrounding the Californian Central Valley
• http://www.actionbioscience.org/evolution/irwin.html -
Miller-Urey experiments published
Biochemists Stanley Miller and Harold Urey, conducted an experiment which demonstrated that several organic compounds could be formed spontaneously by simulating the conditions of Earth's early atmosphere. .designed an apparatus which held a mix of gases similar to those found in Earth's early atmosphere over a pool of water, representing Earth's early ocean. Electrodes delivered an electric current, simulating lightning, into the gas-filled chamber. -
Rosalind Franklin works with DNA and X-Ray crystallography and develops “Image 51”
he nickname given to an X-ray diffraction image of DNA taken by Raymond Gosling in May 1952, working as a PhD student under the supervision of Rosalind Franklin, It was critical evidence in identifying the structure of DNA.
the image became a crucial data source[9] that led to the development of the DNA model and confirmed the prior postulated double helical structure of DNA, which were presented in the articles in the Nature journal by Raymond Gosling. -
Watson and Crick propose the double helix model of DNA structure
The discovery is largely concerned with understanding how genes control the chemical processes within cells. In short order, their discovery yielded ground-breaking insights into the genetic code and protein synthesis. During the 1970s and 1980s, it helped to produce new and powerful scientific techniques, specifically recombine DNA research, genetic engineering, rapid gene sequencing, and monoclonal antibodies -
Meselson and Stahl work with
The Meselson–Stahl experiment is an experiment by Matthew Meselson and Franklin Stahl in 1958 which supported Watson and Crick's hypothesis that DNA replication was semiconservative. In semiconservative replication, when the double stranded DNA helix is replicated, each of the two new double-stranded DNA helices consisted of one strand from the original helix and one newly synthesized. -
Nirenberg cracks the genetic code
The experiment deciphered the first of the 64 triplet codons in the genetic code by using nucleic acid homopolymers to translate specific amino acids.
https://en.wikipedia.org/wiki/Nirenberg_and_Matthaei_experiment -
Apollo 11 lands on the moon
• July 20, 1969.
• The first mission in humankind history that aimed to put foot steps on the moon. And Neil Armstrong was the first astronaut to be on the moon.
• https://www.nasa.gov/mission_pages/apollo/missions/apollo11.html -
Kary Mullis develops Polymerase Chain Reaction
Kary Banks Mullis (born December 28, 1944) is a Nobel Prize-winning American biochemist. In recognition of his improvement of the polymerase chain reaction (PCR) technique, he shared the 1993 Nobel Prize in Chemistry with Michael Smith[3] and earned the Japan Prize in the same year.
https://en.wikipedia.org/wiki/Kary_Mullis -
Australopithicus afarensis nicknamed “lucy” fossil discovered
Lucy is the common name of AL 288-1, several hundred pieces of bone fossils representing 40 percent of the skeleton of a female of the hominin species Australopithecus afarensis. The skeleton presents a small skull akin to that of non-hominin apes, plus evidence of a walking-gait that was bipedal and upright, akin to that of humans (and other hominins); this combination supports the view of human evolution that bipedalism preceded increase in brain size. -
The Sanger Technique is developed
Sanger sequencing is a method of DNA sequencing first commercialized by Applied Biosystems, based on the selective incorporation of chain-terminating dideoxynucleotides by DNA polymerase during in vitro DNA replication -
43. Deep sea hydrothermal vents and associated life around them are discovered
In 1977, scientists exploring the Galápagos 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 to 400 °C (750 °F)—in such a short distance.
https://www.nationalgeographic.org/media/deep-sea-hydrothermal-vents -
Tommie Lee Andrews is convicted of rape
Tommie Lee Andrews was convicted of the rape of a Florida woman in 1987. He was the first American ever to be convicted in a case that utilized DNA evidence. Semen retrieved from the crime scene matched blood drawn from Andrews. After he was convicted, the overall use of DNA evidence/profiling in courts became a national topic.
ps://ransombiotechproject.weebly.com/tommie-lee-andrews-rape.html -
“Reproductive isolation as a consequence of adaptive divergence in Drosophila pseudoobscrura” published
• First published: September 1989 -
The Innocence Project is founded
• The Innocence Project was established in the wake of a landmark study by the United States Department of Justice and the United States Senate, in conjunction with the Benjamin N. Cardozo School of Law, which found that incorrect identification by eyewitnesses was a factor in over 70% of wrongful convictions
• https://en.wikipedia.org/wiki/Innocence_Project -
Endosymbiosis is described by Lynn Margulis
She knew that scientists had been struck by the similarity ever since the discovery of mitochondria at the end of the 1800s. Some even suggested that mitochondria began from bacteria that lived in a permanent symbiosis within the cells of animals and plants. There were parallel examples in all plant cells. Algae and plant cells have a second set of bodies that they use to carry out photosynthesis. -
Theodosius Dobzhansky publishes Genetics and the Origin of Species
the Modern Synthesis of Evolutionary Theory, which embodies a complex array of biological knowledge centered around Darwin’s theory of evolution by natural selection couched in genetic terms. The epithet “synthetic” primarily alludes to the artful combination of Darwin’s natural selection with Mendelian genetics, but also to the incorporation of relevant knowledge from biological discipline -
Sahelanthropus tchadensis fossil discovered
• Sahelanthropus tchadensis is one of the oldest known species in the human family tree. This species lived sometime between 7 and 6 million years ago in West-Central Africa (Chad). Walking upright may have helped this species survive in diverse habitats, including forests and grasslands. Although we have only cranial material from Sahelanthropus, studies so far show this species had a combination.
• http://humanorigins.si.edu/evidence/human-fossils/species/sahelanthropus-tchadensis -
Human genome is fully sequenced
• April 14, 2003
• The human genome has determined the exact order for the first time using sample DNA from volunteers.
• https://www.genome.gov/11006943/human-genome-project-completion -
Homo denisova fossil discovered
In 2008, a small fossil finger bone was found at the Denisova Cave in the Altai mountains in southern Siberia. the bone seemed unusual, and it was assumed to belong to one of the Neandertals living there in that time period, between 30,000 and 48,000 years ago. When the mitochondrial DNA of the bone was sequenced in May 2010 however, it belonged neither to a Neandertal nor to a modern human. The finger was nicknamed the X-Woman, X for 'unknown' and 'woman' because mtDNA is maternally inherited. -
CRISPr/CAS 9 is identified and described
CRISPR-Cas9 is a genome editing tool that is creating a buzz in the science world. It is faster, cheaper and more accurate than previous techniques of editing DNA and has a wide range of potential applications. https://www.yourgenome.org/facts/what-is-crispr-cas9 -
Richard L Bible is executed
Richard L. "Ricky" Bible, 49, of Flagstaff, was pronounced dead by lethal injection at 11:11 a.m. Thursday at the Arizona Department of Corrections Central Unit. http://azdailysun.com/news/local/crime-and-courts/flagstaff-murderer-ricky-bible-executed/article_83b0572d-bc3e-57fc-95c5-a81f7484aecd.html -
Barbara McClintock describes transposons
By the 1970s the great strides made in molecular biology led to the discovery of transposons in other organisms, starting with viruses and bacteria. We now know that transposons constitute more than 65% of our genomes and approximately 85% of the maize genome http://www.pnas.org/content/109/50/20198.full -
Dolly the sheep is cloned
This week’s Retro Report video tells the story of Dolly the sheep, the first clone of an adult mammal. The Scottish scientists who created her recall the painstaking process of trying to get the experiment to work. After hundreds of tries, they successfully took a cell from an adult sheep, fused it to another sheep’s unfertilized egg and implanted the resulting embryo in a surrogate -
Beadle and Tatum publish the 1 gene-1 enzyme hypothesis
George W. Beadle's One Gene-One Enzyme Hypothesis. The one gene–one enzyme hypothesis, proposed by George Wells Beadle in the US in 1941, is the theory that each gene directly produces a single enzyme, which consequently affects an individual step in a metabolic pathway
