Timeline assignment/The Cell Germ Theory

The Development of

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The Cell/Germ Theory

1520

384-322 bC. E

1578-1657

1347 - 1351

The Black Death

Aristottle

Small poxs in America

William Harvey

1577-1644

1590

541-755 AD

Jan Baptista van Helmont

1440

The Justinianic Plage

The first compound microscope

Creation of the first printing

The Development of

The Cell/Germ Theory

17th Century

1617-1619

1668

1665

“Where does life come from?”

Cornelius Drebbel

Micrographia

Redi

1609

1666

1673

1659

Galileo Galilei and his simple microscope

Leeuwenhoek

The discovery of bacteria

Atanasio Kircher

The Development of

The Cell/Germ Theory

1796

1770

1748

Edward Jenner

Baron d'Holbach

John Needham

18th Century

1802-1804

1770´s

1769

1714

Haitian Revolution and the French Army

Lazzaro Spallanzani

Smallpox Inoculation

The Development of

The Cell/Germ Theory

1846-1847

1839

1831

Jugo von Mohl

Theodor Schwann

19th Century

Robert Brown

1830

1856

1838

1845

The Improvment fo the microscopes

William Henry Perkin

Matthias Jacob Schleiden

Alexander Carl Henrich Braun

The Development of

The Cell/Germ Theory

And that´s all

The end of the 19th

1858

1870

1860

Robert Koch

Louis Pasteur

Rudolph Virchow

Acceptance of Biogenesis over Abiogenesis

Robert Koch

• While Pasture works in Paris, Koch works in Germany
• In the 1870s he builds on Pastures work around cell theory and comes up with the idea of “germs” as a way diseases spread. He designs an experiment to prove this idea.
• With Koch’s test and experimentation he proves that microscopic organisms (Germs) can and often do spread disease.

Galileo´s microscope

• With the first compound microscope by Zacharias, many scientists experimented with the microscope and shared their results with each other.
• In 1609, Galileo used his optical system in astronomy to create the first simple microscope.

The Justinianic Plague

During the VI century, ther was a huge epidimic that afected somo places like Asia, Europe and Africa. It caused the death of 50 millions of people, almost 20% of the population who live in century VI and the fall of the Rome empire.

Rudolph Virchow

Writes in 1858, “Cells are the last link in a great chain [that forms] tissues, organs, systems, and individuals…where a cell exists, there must have been a pre-existing cell…Throughout the whole series of living forms…there rules an eternal law of continuous development.”

Acceptance of Biogenesis over Abiogenesis

• As a result of Pasteur’s experiment, all reputable scientists and much of the public accepted biogenesis by the end of the 19th century.
• Microscopes with the ability to magnify 2000x the size of the object, enable biologists to observe and identify cells and many of the smaller structures within them.

Louis Pasteur

1860, offers a prize to anyone who can settle the debate on spontaneous generation. French biologist, Louis Pasteur (1822-1895) decides to take up the challenge. He disproves spontaneous generation and concludes that living organisms do not arise from non-living matter!

Atanasio Kircher

In 1659, with the help of a suitable compound microscope, he would have seen bacteria, which are also cells, describing them in the blood of plague patients as shingles or tiny worms.

the black death

One of the first pandemics which afected whole Europe between 1347 to 1351.

The Black Death killed approximately 25-30 million people. The Black Death was very contagious, and some of the symptoms that people presented were: sudden onset fever, chills, headache and generalized pain, weakness, nausea and vomiting.

1520 SMALLPOXS IN AMERICA

• Explores in 1520 move from Europe to the Amercicas.
• Virus arived by the captain Pánfilo de Narváez´s black slave who has smallpoxs and at the end infect all the indigenous population of the America.
• The European Invasion to the Americas caused the dead of at least the 95% of the population, during almost hundreds of years.

Jan Baptista van Helmont

• 1577-1644
• A firm believer in abiogenesis
• “Mixing a dirty shirt with several wheat grains would produce adult mice after 21 days”
• Played an important role in our scientific understanding of photosynthesis and identified the chemical compounds carbon dioxide and nitrogen oxide.

Leeuwenhoek

• In 1666, Antony reads Hooke’s book
• Designs his own microscopes to examine specimens for himself.
• He designs simple, tiny microscopes

Francesco Redi

• 1629-1697
• Develops controlled biological experiments.
• Discovers that maggots do not appear in meat if flies cannot land on it.
• Some scientists begin to doubt the theory of spontaneous generation.

Robert Hooke

• Robert Hooke was interested in studying all the sciences he could, creating inventions that could measure and understand natural phenomena.
• In 1665 he published his book "micrographia" where he would share his discoveries after having used a compound microscope. The magnification reveals empty room-like compartments. Hooke calls these compartments “cells”.
• That same year, he perfected the compound microscope to achieve a description of the cell. He achieved this by basing himself on the functional principle of Galieo Galilei's astronomical telescope.

The discovery of bacteria

• 11673 – writes the first of a long list of letters, spanning about 50 years to the Royal Society.
• He describes that he sees “animalcules” in standing water.
• Hooke later prooves Leeuwenhoek’s findings.
• 1683, examines plaque from teeth. He observes “many very little living animalcules, very pretty a-moving” – The discovery of bacteria is made!

Cornelius Drebbel

From 1617 to 1619, physicist Cornelius Drebbel creates a two-lens microscope with a single convex objective and eyepiece. It is not known for sure if he is the true author, but this creation is attributed to him.

Aristotle

• Greek Philodopher (384 - 322)
• Classifed all living matter into two categories:

-Plants and Animals

• He writes that living organisms can arrise spontaneously from non-living matter.

William Harvey

• The English physicist William Harvey was born in 1578-1657.
• He challenged strongly held beliefs about the origin and workings of life.
• He suggested that maggots hatch from eggs that are too small to be seen.
• He went down in history for being the first scientist to correctly discover the circulation and properties of blood as it is distributed throughout the body through the pumping of the heart.

Creation of the first printing

• During the Middle Ages and early modern era, in 1440 the German Johannes Gutenberg invented what is the first printing press in the world.
• For science, the invention of the printing press would allow scientists to publish their research and discoveries to more people.

The Royal Society of London

• Scientists and thinkers of the 17th century debate the nature of reproduction as they seek answers to the questions, “Where does life come from?”
• 1602, English monarch King Charles II grants a charter to the Royal Society of London for the Promotion of Natural Knowledge. Members of the Royal Society share and debate their knowledge by publishing books, writing letters, and attending meetings.

The First Compound Microscope

Zacharias Janssen was experimenting with a variety of lenses and as if it were destiny, he invent the first compound microscopes by lining up two lenses to produce magnified images.

Smallpox Inoculation

1714 smallpox inoculation is recorded in Royal Society journal and finds it way as a practice in Europe.

John Needham

• 1748 – English naturalist and priest
• Designs an experiment to support the idea of spontaneous generation (next slide).
• Boils meat broth and then seals it in a flask.
• He leaves a second flask with boiled broth open.
• Within days, both flasks are teeming with micro-organisms.
• Needham writes that his results support the theory of spontaneous generation.

Baron d'Holbach

• Uses the discovery and previous evidence of previous Scientists especially Needham and philosophers and writes an Atheist work The System of Nature.
• Needhams work is cited in this work.

• This shook the world Fredrick the great writes of this: "When one speaks in public he should consider the delicacy of superstitious ears; he should not shock anybody; he should wait till the time is sufficiently enlightened to let him think out loud.”

1700´s

• Microscope advancements – sturdier and easier to use.
• Still no microscope is as advanced or a clear as van Leeuwenhoek’s.
• The System of Nature is published.

18th Century

• The microscope becomes more common
• Found in the homes of the wealthy as a curiosity piece.
• Horrified by the sight of a magnified flea, a prominent individual publicly denounces the microscope as an “instrument of evil”

Jenner and Vaccination

• Edward Jenner observes those who work closely with cows (milk maids) seem less affected if at all by smallpox outbreaks
• He also observes that cows get form of poxs known as cowpox
• in 1796 Jenner convinces a farmer to let his 8 year old be infected with cowpox
• The boy is protected for the rest of his life from smallpox
• Vaccination from vaccinus or “From the cow”

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Lazzaro Spallanzani experiment

• Learns of Needham’s experiment and repeats it only boils the broth much longer. The sealed flask doesn’t become cloudy days later.
• Supporters of spontaneous generation claim that the boiling killed the vital principle (the thing in the air that is responsible for life to arise from non-living matter).

Haitian Revolution and the French Army

• Napoleon Bonaparte sends 20000 troops and his brother in law to put down a revolution in Haiti
• French troops take control of populations centers of Haiti and rebels hide in the wilderness “Wait for the rains”
• Yellow fever sets in as the mosquitoes start to spread. The rebels from Africa are mostly immune. The French are not. 50,000 men are reduced to 3000.

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1830

• Advancements in glass making techniques
• English manufacturers compete to produce the best microscope.

• 1830’s biology is evolving from a collection of assorted facts into and organized body of knowledge. Better optical theory leads to improved microscopes, which biologists use to study cells intensively.

Robert Brown

1831 – observes that all cells from a variety of backgrounds, seem to contain a dark region near the centre, known as the nucleus.

Theodor Schwann

• 1810-1882 – writes “all animals are made up of cells”
• Schwann also modifies and expands Schleiden’s work to say that “Cells are organisms, and entire animals and plants are collectives of these organisms.”

Alexander Carl Henrich Braun

Alexander Carl Henrich Braun writes “The cell is the basic unit of life”

19th Century

• Support for and interest in science is very high.

• Public lectures are popular.
• Textbooks are developed by Jane Haldiman, in 1809 to help young people learn about science.

• The terms “cell”, “cellular system” and “cell tissue” are used in these textbooks.

Jugo von Mohl

• German biologist Jugo von Mohl writes “Protoplasm is the living substance of the cell”
• In 1847 he modifies his statement and claims “Cells are made of protoplasm enveloped by a flexible membrane”.

Matthias Jacob Schleiden

1838, a German botanist writes “All plants are made of cells” which decribes his serchings about plants in a microscope and his conclusions were that "All the plants are also made of cells"

William Henry Perkin

• William Henry Perkin accidentally synthesized mauve, the first commercially available synthetic dye.
• The 18 year old, English chemistry student quickly develops techniques for staining slide specimens quickly with it.

The 4 main hypotheses of Cell Theory

• All living organisms are composed of one or more cells.
• All cells are composed of the same basic functional parts (Lipids, DNA, proteins and carbohydrates)
• All cells are derived from pre-existing cells.
• In a multicellular organism, the activity of the entire organism depends on the total activity of its independent cells.