History of Science and Biology

Timeline created by yomelim1
  • -162 BCE

    Galen of Pergamon

    Galen of Pergamon
    Galen was very famous for his anatomical and medical studies. He mainly dissected African monkeys, pigs, sheep, and goats to improve surgical skills. He identified seven pairs of cranial nerves and described the valves of the heart. One of his most important discoveries was that the arteries carry blood, not air. His most well known experiment was the vivisection tying off the laryngeal nerve to show that the brain controls the voice
  • Lamarck Develops Hypothesis of Evolution

    Lamarck Develops Hypothesis of Evolution
    Jean-Baptiste Lamarck is a French naturalist, who is well known for his theory of inheritance of acquired characteristics. He believed that if an organism changes to adapt to its environment, those changes are passed to their offspring. He strongly believed that the changes made were by what the organism wanted or needed. One of this theories were that Giraffes used to have short necks, but over time developed long necks.
  • The voyage of the HMS Beagle

    The voyage of the HMS Beagle
    The voyage of HMS Beagle is a book where Charles Darwin wrote about his trip around the world. The trip took 5 years at South America. Darwin observed many animals and plants. This event shaped Darwin's career into becoming a naturalist. This book was published in 1839, but the trip took place in 1831.
  • Alfred Russel Wallace Ideas of Evolutionary Processes

    Alfred Russel Wallace Ideas of Evolutionary Processes
    Alfred Russel Wallace was British naturalist, explorer, and biologist. It was not until 1843 when Wallace become passionate about collecting and studying beetles. 5 years later Wallace decided to go on a trip to seek evidence of evolution. He published a book called, The Malay Archipelago, where he describes his work and experiences of evolutionary change.
  • Publication of On the Origin of Species

    Publication of On the Origin of Species
    On the Origin of Species is a book published by Charles Darwin, an english naturalist, geologist and biologist. Darwin was interested about natural selection so decided to go around the world to learn more about the subject. After his trip, he kept all the notes and created more detailed ones for more than 10 years. His book contains 490 pages of the theories Darwin had about evolution. It contained detailed examples of natural selection.
  • Louis Pasteur Experiment

    Louis Pasteur Experiment
    Louis Pasteur conducted an experiment to test whether sterile nutrient broth could spontaneously generate microbial life. This experiment is called Refute Spontaneous Generation. Pasteur conducted two experiments. He found that without the introduction of dust no life can arose.
  • The Germ Theory

    The Germ Theory
    Because of Louis Pasteur, we now are aware that diseases are caused by microorganisms. In the mid-19th century Pasteur showed that fermentation and putrefaction are caused by organisms in the air. In the 1860s his teammate revolutionized surgical practice by utilizing carbolic acid (phenol) to exclude atmospheric germs. In the 1880s another teammate identified the organisms that cause tuberculosis and cholera.
  • Gregor Mendel: Inheritance of Traits in Pea Plants

    Gregor Mendel: Inheritance of Traits in Pea Plants
    Gregor Mendel was a Central European monk, who did many researches regarding genetics. Mendel did his research on plants, however; his findings also applied to people and animals. Mendel discovered that certain traits show up in the offspring without any blending of parent characteristics. He also found that a trait may not show up in an individual, but can still be passed on to the next generation.
  • Hardy-Weinberg Equation

    Hardy-Weinberg Equation
    G. H. Hardy and Wilhelm Weinberg developed an equation to calculate genetic variations. The equation, p2 + 2pq + q2 = 1, expresses the amount of genetic variation in a population and will remain constant from one generation to the next. https://www.nature.com/scitable/definition/hardy-weinberg-equation-299
  • The Discovery of Sex Linkage

    The Discovery of Sex Linkage
    Thomas Hunt Morgan was the first man ever to discover sex linkage. One day in his lap, he spotted a fruit fly that was very different from the others. He decided to get the fruit fly and make an experiment with it. From this, he discovered mutant traits and also that some certain characteristics are sex-linked.
  • The Bohr Model

    The Bohr Model
    The Bohr Model of Atom explains the structure of atoms. This model was constructed by Niels Bohr. The model explains how atoms absorbs or emits radiation only when the electrons abruptly jump between allowed, or stationary, states.
  • Transforming Principle

    Transforming Principle
    Frederick Griffith conducted an experiment with bacteria to find a vaccine against the flu, by doing this experiment he discovered that gene transfer took place between two different factors. Griffith's experiment showed that bacteria was able to transfer their genetic information by a process that he called transformation.
  • Biological Species Concept

    Biological Species Concept
    The Biological Species Concept is when organisms are classified in the same species if they are potentially capable of interbreeding and producing fertile offspring. This concept was developed by Ernst Mayr, whom was very interested in bird taxonomy.
  • Genetics and the Origin of Species

    Genetics and the Origin of Species
    Genetics and the Origin of Species is a book published by Theodosius Dobzhansky. The book is considered to be the most important of all time. The book is about modern evolution, mostly genetics. Dobzhansky talks about mutation, natural selection, and speciation throughout his book. The book also talks about evolution in depth as a process over time that regards diversity.
  • Transposon

    Transposon aka “jumping genes” are a class of genetic elements that can “jump” to different locations within a genome. Most transposons become extremely inactive and then will not move for a long period of time. Barbara McClintock discovered transposon and additionally discovered three basic types of transposon
  • One Gene-One Enzyme Hypothesis

    One Gene-One Enzyme Hypothesis
    One Gene-One Enzyme Hypothesis is the theory that each individual gene produces a single enzyme. This theory was developed by George Wells Beadle, Boris Ephrussi, and Edward Lawrie Tatum. This discovery helped researchers characterize genes as chemical molecules, and helped them determine the functions of those molecules.
  • Jacques Cousteau develops SCUBA

    Jacques Cousteau develops SCUBA
    Jacques Cousteau was a filmmaker, scientist, photographer, inventor, and explorer, who invented diving and scuba devices. He invented the famous Aqua-Lung, which provided air for scuba divers. Before the invention of Cousteau, others invented underwater breathing devices, but failed because divers would die of oxygen toxicity. In 1946, Aqua-lung was safe to use.
  • Avery-Macleod-McCarty experiment

    Avery-Macleod-McCarty experiment
    Oswald Avery, Colin MacLeod and Maclyn McCarty conducted an experiment to demonstrate the role of DNA. By doing this, they discovered that DNA, in fact carries genetic information. To do so, they started with a bacteria and used mice to demonstrate.
  • Australopithicus Afarensis Fossil Discovered

    Australopithicus Afarensis Fossil Discovered
    At Ethiopia’s Afar Triangle, paleoanthropologist Donald Johanson and graduate student Tom Gray found the remains of an ape-like hominid. They found pieces of leg, pelvis, hand and arm bones ,lower jawbone, teeth and part of the skull. The remains seemed to be three million years old. Many examinations were made and showed that the remains were from a female weighing only 60 pounds and walked upright.
  • Image 51

    Image 51
    Image 51 is an X-ray diffraction of DNA. This image was taken by Rosalind Franklin, who discovered that DNA was composed of a double helix. Although she was the only one who was able to get the image, she did not receive enough credit like Watson and Crick.
  • The Hershey and Chase Experiments

    The Hershey and Chase Experiments
    A. D. Hershey and Martha Chase were two geneticists, who conducted experiments to further proof that genes were DNA. They first started with a DNA virus to prove their theory. First the virus attached to the cell, it injected its DNA, made copies of itself, cell erupted, and virus spread. From this experiment Hershey and Chase found that dNA was able to direct the formation of new virus.
  • Miller-Urey Experiments

    Miller-Urey Experiments
    Stanley L. Miller and Harold C. Urey conducted an experiment to test out what kind of environment was needed for life to form. The experiment consisted of water, methane, ammonia, and hydrogen. After conducting the experiment, they found that the molecules produced were simple organic molecules, far from a complete living biochemical system. Life can be formed/created without requiring life to synthesize them first.
  • Discovery of the Double Helix

    Discovery of the Double Helix
    James Watson and Francis Crick made this huge discovery of the double helix. They also discovered the genetic code and protein synthesis. The two used their own knowledge and skills to achieve this discovery. They had to learn genetics, biochemistry, chemistry, physical chemistry, and X-ray crystallography.
  • Meselson-Stahl Experiment

    Meselson-Stahl Experiment
    Meselson and Stahl conducted an experimental to prove their claim of DNA replication. They obtained evidence that each DNA strand served as a template for new synthesis. Results showed that after one generation, the double stranded DNA is 1/2 from a parent and 1/2 light from the replication
  • Endosymbiosis

    Lynn Margulis was responsible for the discovery of endosymbiosis. Her discovery showed that there was bacteria living inside the mitochondria. She also found that the evidence for endosymbiosis applies to other cellular organelles as well. Endosymbiosis is very important because it provides the explanation of structures.
  • Genetics Code Cracked

    Genetics Code Cracked
    Marshall Nirenberg discovered the first DNA triplet, cracking the code in an experiment. In this experiment, he discovered that each codon consisted of three bases in a specific order. He also discovered the functions of protein synthesis.
  • Nothing in Biology Makes Sense Except in the Light of Evolution

    Nothing in Biology Makes Sense Except in the Light of Evolution
    Nothing in Biology Makes Sense Except in the Light of Evolution is an essay published by Theodosius Dobzhansky. This essay is about the importance of organismic biology. In his essay he uses species like monkeys, tuna, kangaroos, and yeast to demonstrate evolution.
  • Spliceosome Discovery

    Spliceosome Discovery
    The spliceosome is made up of a variety of RNA and protein molecules. Spliceosome removes introns. Spliceosome are responsible for the splicing of pre-mRNA.
  • The Sanger Technique

    The Sanger Technique
    The Sanger Technique is a method used to sequence DNA. It was developed by Frederick Sanger. This method requires a single-stranded DNA template in order for the DNA sample to be divided into four separate sequencing reactions.
  • Discovery of Hydrothermal Vents

    Discovery of Hydrothermal Vents
    Scientists made an amazing discovery at the bottom of the Pacific Ocean. Their discovery consisted of seafloor vents that gushed and shimmered warm and mineral-rich fluids into the cold. They also found that the vents were full of unexpected life.
  • Polymerase Chain Reaction

    Polymerase Chain Reaction
    Thanks to Kary B Mullis for inventing The Polymerase Chain Reaction, scientists can now make millions of copies from sample a of DNA. This technique has tremendously helped with the detection of the AIDS virus in human cells. It is also used by criminologists to do DNA comparison by linking specific persons to samples of blood or hair.
  • Tommie Lee Andrews Convicted

    Tommie Lee Andrews Convicted
    Tommie Lee Andrews is a man who was accused of breaking into the home of a 27-year-old Orlando woman, raping and stabbing her on May 9, 1986. On February 5,1988, he was found guilty after a DNA test. The DNA test found the ''fingerprint'' of Tommy Lee Andrews' blood matched that of the rapist's semen.
  • Innocence Project

    Innocence Project
    Innocence Project was founded by Peter Neufeld and Barry Scheck. The Innocence Project is about freeing innocent people who remain incarcerated and make the system responsible for their unjust imprisonment.
  • Dolly The Sheep

    Dolly The Sheep
    Dolly the sheep was the first animal to ever have been successfully cloned from an adult cell. She was cloned at the Roslin Institute in Midlothian, Scotland and only lived for six years.
  • Sahelanthropus Tchadensis Fossil Discovered

    Sahelanthropus Tchadensis Fossil Discovered
    Sahelanthropus tchadensis is a name researchers created after they discovered fossils of an ape-like/human-like organism. This discovery was made in Northern Chad, where nine cranial specimens were found. Researchers believe this organism walked upright since underneath the skull there was an opening instead of towards the back like in other apes.
  • Human Genome Fully Sequenced

    Human Genome Fully Sequenced
    A genome is a complete set of DNA made of two strands. Humans contain 23 chomrosomes, which contain many genes, and those genes contain approximately 30,000 genes. The human genome was fully sequenced by determining the exact order of the base pairs in the DNA. To sequence, researchers cloned base pairs in bacteria. Next they map the clone and after they are loaded into a machine.
  • CRISPr-CAS9 is Identified

    CRISPr-CAS9 is Identified
    CRISPr is a bacterial defense system that serves as a genetic memory that helps the cell detect and destroy viruses. CAS9 is an enzyme produced by CRISPr that binds to the DNA and cuts it, shutting the targeted gene off. CRISPr-CAS9 was discovered by Francisco Mojica in archaea.

  • Homo Denisova Fossil Discovered

    Homo Denisova Fossil Discovered
    In the Altai mountains in southern Siberia, a small fossil finger bone was found at the Denisova Cave. After doing many DNA testing, researches couldn't relate this fossil with any other ancient findings. Later on they found 2 molar tooth. Then they were able to discover that the findings belonged to a female. The fossil found can be related to early modern humans and Neandertals.
  • Richard L Bible Executed

    Richard L Bible Executed
    Richard L Bible was an Arizona resident who raped and murdered a nine year old girl named Jennifer Wilson. He was arrested in 1988 and pleaded innocent, but from DNA testing, legal officials found that the blood from Bible's shirt was from Jennifer. They also found hair that seemed to belong to him at the crime scene. After 23 years, Bible was executed by lethal injection at the state prison