Scientists Through History

1
Scientists Through History

• Famous Scientists and their Accomplishments
  Time line of science

2
Aristotle

• Classification of nature into groups, subgroups,
  and gave birth to the profession of taxonomy.
• Blooded (vertebrates)
• Bloodless (invertebrates)
• He created Natures scale and defined nature
  purpose Inanimate to Living Beings (possibility
  of changing) to Plants and Living beings
  (mobile).
• Worked out the hydrologic cycle
• Described life cycles, species only born from
  same and reproduce the same.

3
Leonardo da Vinci

• Determined trees age by the of rings in the
  trunk
• Studied Anatomy Extensively
• Studied heart and eye extensively
• Tried to recreate birds flight.
• Was the first one to propose a theory about the
  creation of fossils.

4
Antony van Leeuwenhoek

• First Simple Microscope
• First to observed unicellular organisms
• Able to calculate the size of bacteria, protozoa,
  sperm cells, stripped muscles and blood cells.
• He built simple microscopes by grinding lenses
• He laid the foundations of the detailed
  observation of the microscopic organisms
• Discovered capillary systems
• Opposed the theory of spontaneous generation,
  proved this by showing fleas and mussels came
  from eggs

5
Robert Hooke (XVIIc)

• Published Microgaphia which is a record of his
  observations in microscopic organisms.
• Devised compound microscope
• Observed and coined the term cells, in cork.
• Numerous other advances in Physics

6
Sir. Francis Bacon

• Change in way of thinking
• Substituted Aristotles deductive reasoning
  (general to particular) for an inductive
  reasoning (particular to general) (Novum Organum)
  nowadays known as the Scientific Method
• First to develope Scientific Method

7
Nicholas Steno

• Made observations on the anatomy of the brain.
• First one to show that the heart has two
  independent pumps
• Discovered that fossils are petrified plants and
  animals
• Established some of the fundamental principles of
  stratigraphy. Rocks form in horizontal positions
• Law of Original Horizontality (Rock formed in
  Horizontal Layers)
• Law of Supperposition
• First use of geology by saying the rocks were
  divided by layers from different times.

8
Francesco Redi

• Italian physician and poet.
• Redi demonstrated in 1668 that rotting meat
  carefully kept from flies will not produce
  maggots, providing experimental evidence against
  the theory of spontaneous generation.

9
George Cuvier

• Studied natural history and comparative anatomy
• Function determines form, as a theory of
  evolution.
• Established extinction as fact.
• Animals were immutable.
• Classified animals by their skeletal structure
• Vertebrata
• Articulata
• Radiata
• Mollusca

10
Carolus Linnaeus

• Considered the father of taxonomy
• Several expeditions in Sweden
• Created a binomial system for naming species
• Studied hyloridization
• Binomial nomenclature (genus then species)

11
Lazaro Spallanzani (1729-1799)

• An Italian naturalist, philosopher, and priest
• Described the regeneration of organs in such
  animals as worms, snails, and frogs.
• He attempted to induce frogs eggs to develop
  artificially by using vinegar and lemon juice

12
Thomas Malthus

• English Economist
• Theories on population
• Plants arithmatic growth
• Animals geometric growth
• Relation of Food and Sex to populations
  Positive
• Relation of Vice and Mersery to populations
  Negative
• No perfect society,
• Darwins Statements about Malthuss work the
  strongest will survive
• Mathus said that man will overpopulate the earth

13
Jean-Baptiste Lamarck

• Theory of evolution based on the use and lack of
  use of some organs
• An organ is used becomes stronger then this
  characteristic will be passes on to offspring
• Heredity
• First to use term Biology
• Theory of Transmutation aquired traits can be
  inherited.

14
Adam Sedgwick

• Explored geology of Scotland and presented his
  research
• Proposed a new division of the geological
  timescale (the Devonian and the Cambrian)
• Published On the Silvarian and Cambrian systems,
  exhibiting the order in which the older
  sedimentary strata suceed each other in England
  and Wales
• Strata, same strata exist separated in space but
  representing the same time.
• Taught Darwin about Geology.

15
Joseph Mendel

• Studied botanics
• Used garden peas to study heredity
• Established the laws of segregation and
  independent assortment.
• First person to trace characteristics of
  succesive generations.
• Published experiments with Plants (Hybrids)
• Heredity character are independent
• They combine at random
• Characters dominant or recessive
• Antagonistic heredity factors never transmitted
  together

16
Thomas Henry Huxley

• He supported the theory of evolution of Darwin
  and convinced people to accept it
• First teacher of biology to use the laboratory
  method.
• Supported Darwins theories
• Punctuated evolution as opposed to Darwin,
  Gradual
• I would rather be a man decended from apes than
  one afraid to face the truth
• Jellyfish microbes in embryos of other organisms

17
Louis Pasteur

• Found Vaccines for rabies, anthrax (sheep),
  chicken cholera, silk worm diseases
• Discovered- germ theory, spontaneous generation
  (living things from non-living) proposed and
  disproved
• Created First vaccines, pasteurization (heat
  killing organisms in milk), immunization
• Gave birth to stereochemistry, microbiology,
  bacteriology, virology

18
Watson and Crick

• Proposed the double helical structure of DNA
• Analyzed and studied the structure of molecules
  that transmit the genetic characteristics from
  one generation to the next.
• X ray defraction used to desifer structure of DNA.

19
Oparin

• 1) Formation of the planet with gases in the
  atmosphere that could serve as the raw materials
  for life. The most widely accepted astronomical
  theory for the origin of the earth and the rest
  of the solar system is that the solar system
  formed about 4.5 billion years ago from a diffuse
  dust cloud.
• 2) Random synthesis of simple organic molecules
  (such as amino acids that make up proteins) from
  the gases in the surrounding atmosphere.
• 3) Formation of larger, more complex molecules
  (Macromolecules) from the simple organic
  molecules, e.g., the formation of simple proteins.

20
Oparin cont

• 4) Formation of coacervates - unique droplets
  containing the macromolecules , i.e., a
  coacervate consists of chemicals suspended within
  a liquid surrounded by a membrane, e.g. a droplet
  consisting of chemicals in water surrounded by an
  oil layer membrane.
• 5) Development of some type of chemical
  organizers that function to give these droplets
  the ability to take in molecules, discharge other
  molecules, and control and maintain a
  characteristic chemical pattern.
• 6) Development of controlled reproduction to
  insure that resultant daughter cells have the
  same chemical capabilities.
• 7) Beginnings of evolutionary developments so
  that a group of cells could adapt to changes in
  the environment over time.

21
Sir Alexander Fleming (1881 - 1955)

• Fleming had discovered the first antibiotic,
  penicillin
• However, it was not until the research work of
  Florey and Chain that penicillin could be
  produced as a drug.