-
130 BCE
Galen of Pergamon describes the human body
The first of the great anatomists was Galen of Pergamon (AD 130-200) who made vast achievements in the understanding of the heart, the nervous system, and the mechanics of breathing.Human dissection was forbidden, he performed many of his dissections on apes.The system of anatomy he developed was so influential that it was used for the next 1400 years. Galen was influential into the 16th century. -
Aristotle describes life with the Scala Naturae
Greek philosopher Aristotle created two classification systems to group living organisms based on several factors, including physical characteristics and perceived mental capacities. Aristotle organized living organisms physically on the basis of movement as well, which included walking, flying and swimming and in intellectual hierarchy through the Great Chain of Being, also called scala naturae. -
Lamarck develops Hypothesis of evolution by means of acquired characteristics
-Lamarck said that change is made by what the organisms want or need.
-Lamarck also believed that evolution happens according to a predetermined plan and that the results have already been decided.
-Lamarck believed that giraffes stretched their necks to reach food. Their offspring and later generations inherited the resulting long necks -
The Voyage of the HMS Beagle
-Beagle set sail from Plymouth on 22 May 1826 on her first voyage, under the command of Captain Stokes.
-FitzRoy heard that he was to be appointed commander of HMS Chanticleer to go to Tierra del Fuego, but due to her poor condition Beagle was substituted for the voyage.
-Second voyage (1831–1836) -
Alfred Russel Wallace published ideas of evolutionary processes
-In 1854, aged 31, Alfred Russel set off on a new voyage: to Malaysia, Singapore, Indonesia and New Guinea.
-He discovered thousands of new species of beetle and he sent over 100,000 specimens of various species back to the UK.
-It was on this expedition that Wallace first described the theory of evolution.
-Wallace returned to the UK from this expedition in 1862, aged 39. -
Louis Pasteur refutes spontaneous generation
Pasteur's experiment is generally known to have refuted the theory of spontaneous generation in 1859
-Pasteur invented the swan-necked flask to create an environment known not to grow microorganisms. After sterilizing a nutrient broth in these flasks, he removed the swan necks of the samples in the control group. Microorganisms grew in the control group, but not the experimental group, supporting biogenesis and rejecting spontaneous generation. -
The Origin of species by means of Natural Selection is published
On this day, Charles Darwin published On the Origin of Species by Means of Natural Selection, or The Preservation of Favoured Races in the Struggle for Life, which immediately sold out its initial print run. By 1872, the book had run through six editions, and it became one of the most influential books of modern times. -
The Germ Theory of Disease is published
-Pasteur discovered that the process was caused by a living organism, which he called ‘ferment’. This work was a turning point in the young chemist’s career – he now began to apply his rigorous experimental methods to biological questions.
-Koch had introduced pure culture and thus founded bacteriology while confirming Bacillus anthracis caused anthrax (1876)
Experiments on the relationship between germ and disease were conducted by Louis Pasteur between 1860 and 1864. -
Gregor Mendel publishes works on inheritance of traits in pea plants
-In 1856, Mendel began a series of experiments at the monastery to find out how traits are passed from generation to generation.
-In 1866, Mendel published the paper Experiments in plant hybridisation.The science community ignored the paper, possibly because it was ahead of the ideas of heredity and variation accepted at the time.
-In the early 1900s, 3 plant biologists finally acknowledged Mendel’s work. Unfortunately, Mendel was not around to receive the recognition as he had died in 1884. -
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. -
T. Hunt Morgan discovers sex-linkage
One day in 1910, American geneticist Thomas Hunt Morgan peered through a hand lens at a male fruit fly, and he noticed it didn't look right. Instead of having the normally brilliant red eyes of wild-type Drosophila melanogaster, this fly had white eyes. Morgan was particularly interested in how traits were inherited and distributed in developing organisms, and he wondered what caused this fly's eyes to deviate from the norm. -
Neils Bohr develops the Bohr model of atom structure
The Rutherford–Bohr model or Bohr model, 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 -
Frederick Griffith describes the process of transformation
Frederick Griffith, established that there was a transforming principle in bacterial genetics in a ground-breaking experiment, performed in 1928.
-He postulated that information could somehow be transferred between different strains of bacteria. -
Theodosius Dobzhansky publishes Genetics and the Origin of Species
-Genetics and the Origin of Species is a 1937 book by the Ukrainian-American evolutionary biologist Theodosius Dobzhansky. -The book popularized the work of population genetics to other biologists, and influenced their appreciation for the genetic basis of evolution The book explains evolution in depth as a process over time that accounts for the diversity of all life on Earth. -
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. -
Beadle and Tatum publish the 1 gene-1 enzyme hypothesis
The one gene-one enzyme hypothesis is the idea that genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn affects a single step in a metabolic pathway. The concept was proposed by George Beadle and Edward Tatum in an influential 1941 paper. In 1941, Beadle demonstrated that one gene in a fruit fly controlled a single, specific chemical reaction in the fruit fly, which one enzyme controlled -
Jacques Cousteau develops SCUBA
In 1942, Jacques Cousteau and Gagnan co-invented a demand valve system that would supply divers with compressed air when they breathed. This modern demand regulator was named Aqua-Lung and its invention eventually opened the door to diving for anyone who was interested. -
Ernst Mayr develops the Biological Species Concept
The development of what became known as the biological species concept began with a paper by Theodosius Dobzhansky in 1935, and was amplified by a mutualistic interaction between Dobzhansky, Alfred Emerson and Ernst Mayr after the second world war. By the 1950s and early 1960s, these authors had developed an influential concept of species as coadapted genetic complexes at equilibrium. -
Avery, MacLoed and McCarty determine that DNA is the molecule that carries the genetic code
In 1944, Oswald Avery, Colin MacLeod and Maclyn McCarty helped demonstrate the role of DNA as the carrier of genetic information by working with the bacterium.
-However, their work was given a head start by a British bacteriologist called Frederick Griffith, who identified something called the ‘transforming principle’. -
The first atomic bomb is used in war
In August 1945, the United States dropped two atomic bombs over the Japanese cities of Hiroshima and Nagasaki. -
Ensatina Ring Species
Robert Stebbin's had proposed in (1949) that the species started off in Northern California and Oregon and then spread south along both sides of the Central Valley, which was too dry and hot for salamanders. Ensatina seemed to represent the whole process of speciation, all the gradual changes that accumulate in two lineages and that wind up making them incompatible with one another. -
Rosalind Franklin works with DNA and X-Ray crystallography and develops “Image 51”
-Rosalind Franklin- Watson and Crick used her x-ray photographs to develop the double helix model of DNA.
-Photograph 51 is the nickname given to an X-ray diffraction image of DNA taken by Raymond Gosling in May 1952 -
Miller-Urey experiments published
The Miller-Urey experiment was an experiment that simulated hypothetical conditions present on the early Earth in order to test what kind of environment would be needed to allow life to begin. The experiment is considered to be the classic experiment on the origin of life. It was conducted in 1953 by Stanley L. Miller and Harold C. Urey at the University of Chicago. -
Watson and Crick propose the double helix model of DNA structure
-The discovery in 1953 of the double helix, the twisted-ladder structure of deoxyribonucleic acid (DNA), by James Watson and Francis Crick marked a milestone in the history of science and gave rise to modern molecular biology
-Without such knowledge, heredity and reproduction could not be understood. They immersed themselves in all the fields of science: genetics, biochemistry, chemistry, physical chemistry, and X-ray crystallography. -
Hershey-Chase experiments are published
Hershey, however, was about to make a discovery that would turn his own notions on end.
-In order to show that proteins carry genetic information, Hershey and his lab technician, Martha Chase,
-The pair reported their findings in a short paper in The Journal of General Physiology titled “Independent Functions of Viral Protein and Nucleic Acid in Growth of Bacteriophage.” This publication catalyzed a storm of activity in the scientific community -
Meselson and Stahl work with DNA replication
The Meselson–Stahl experiment was an experiment by Matthew Meselson and Franklin Stahl with some additional help from a Canadian biologist, Mason MacDonald, and Canadian nuclear physicist, Amandeep Sehmbi, in 1958 which supported the hypothesis that DNA replication was semiconservative. -
Endosymbiosis is described by Lynn Margulis
The Endosymbiotic Theory was first proposed by former Boston University Biologist Lynn Margulis in the 1960's and officially in her 1981 book "Symbiosis in Cell Evolution". -
Nirenberg cracks the genetic code
In 1961 Marshall Nirenberg, a young biochemist at the National Institute of Arthritic and Metabolic Diseases, discovered the first "triplet"—a sequence of three bases of DNA that codes for one of the twenty amino acids that serve as the building blocks of proteins. Subsequently, within five years, the entire genetic code was deciphered. -
Apollo 11 Lands on The Moon
Apollo 11 was the first spaceflight that landed humans on the Moon. Mission commander Neil Armstrong and pilot Buzz Aldrin landed the lunar module Eagle on July 20, 1969 -
Theodosius Dobzhansky publishes “Nothing in Science Makes Sense Except in the Light of Evolution.”
Theodosius Dobzhansky played a crucial role in bridging the gap between theoretical and empirical approaches in genetics and in promoting the Neo-Darwinian synthesis. -
Australopithicus afarensis nicknamed “lucy” fossil discovered
-Paleoanthropologist Donald Johanson and graduate student Tom Gray stumbled upon the partial remains of a previously unknown species of ape-like hominid. Nicknamed “Lucy,” the mysterious skeleton was eventually classified as a 3.2 million-year-old
-“Australopithecus afarensis”—one of humankind’s earliest ancestors. -
Dolly the sheep is cloned
Dolly the Sheep. Dolly (July 5, 1996 - February 14, 2003), a ewe, was the first mammal to have been successfully cloned from an adult cell. She was cloned at the Roslin Institute in Midlothian, Scotland, and lived there until her death when she was six years old. Her birth was announced on February 22, 1997. -
The Sanger Technique is developed
Fred Sanger developed the first technique for sequencing DNA. DNA is replicated in the presence of chemically altered versions of the A, C, G, and T bases. During Sanger sequencing, DNA polymerases copy single-stranded DNA templates by adding nucleotides to a growing chain (extension product). The dideoxy method of DNA sequencing developed by Sanger et al. 1977 -
Spliceosomes were discovered and described
In 1977, work by the Sharp and Roberts labs revealed that genes of higher organisms are "split" or present in several distinct segments along the DNA molecule
- Spliceosomes are huge, multimegadalton ribonucleoprotein (RNP) complexes found in eukaryotic nuclei.
-Spliceosomes contain both proteins and RNAs.
-They assemble on RNA polymerase II transcripts from which they excise RNA sequences called introns and splice together the flanking sequences called exons. -
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 also realized that an entirely unique ecosystem, including hundreds of new species, existed around the vents. -
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. Scientists adapted this system so that it could be used in other cells from animals, including mice and humans
The first description of what would later be called CRISPR was from Osaka University researcher Yoshizumi Ishino in 1987 -
Tommie Lee Andrews is convicted of rape
Feb. 5— A jury today convicted Tommie Lee Andrews of rape on the basis of the DNA ''fingerprint'' of his blood. -
Drosophila Pseudoobscrura
Eight populations of the Drosophila pseudoobscrura species were studied to receive information into the process of the development reproductive isolation. All eight were derived from the a single population collected at Bryce canyon. -Diane M.B. Dodd -
The Innocence Project is founded
The Innocence Project, founded in 1992 Peter Neufeld and Barry Scheck at Cardozo School of Law xonerates the wrongly convicted through DNA testing and reforms the criminal justice system to prevent future injustice. -
Sahelanthropus tchadensis fossil discovered
Sahelanthropus tchadensis was discovered by Ahounta Djimdoumalbaye in 2001, is one of the oldest known species in the human family tree.Lived six to seven million years ago. Only cranial material was discovered. -
Human Genome Fully Sequenced
-On June 26, 2000, the International Human Genome Sequencing Consortium announced the production of a rough draft of the human genome sequence. In April, 2003, the International Human Genome Sequencing Consortium announced a finished version of the human genome sequence. This version, which is available to the public, provides nearly all the information needed to do research using the whole genome.
- Sequencing means determining the exact order of the base pairs in a segment of DNA. -
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 finger bone was nicknamed the X-Woman, X for 'unknown' and 'woman' because mtDNA is maternally inherited, but in fact it didn't necessarily belong to a female.
- It remains unclear what species the genome belongs to, but in the absence of good information about their anatomy, they are being called 'Denisovans'. -
Richard L Bible is executed
Flagstaff murderer Ricky Bible executed," by Larry Hendricks. (Friday, July 1, 2011 5:10 am)
