Development of Scientific Process Abiogenisis to Biogenisis

Science vs the Churches The Gauntlet 1870

Spontaneous Generation Abiogenesis Since Aristotle (4th Century BC), it was believed that non-living objects could give rise to living organisms. – Based on observations like: Nile flooding Moldy grain and mice Sewers and rats

Recipe for Life Recipe for bees: – Kill a young bull, and bury it in an upright position so that its horns protrude from the ground. After a month, a swarm of bees will fly out of the corpse.

How to Create Mice Jan Baptista van Helmont’s recipe for mice: – Place a dirty shirt or some rags in an open pot or barrel containing a few grains of wheat or some wheat bran, and in 21 days, mice will appear. There will be adult males and females present, and they will be capable of mating and reproducing more mice.

Life Force Living things had a live force that was transferred to objects The live force could generate new forms of life Most common observations were from meat, broth etc. that people had in their homes – often associated with flies.

Biogenesis Until the 19 th Century, Spontaneous Generation was accepted Development of ideas and technologies brought forth the idea of Biogenesis – the process of life forms producing other life forms, e.g. a spider lays eggs, which develop into spiders.

Progression of Ideas and Innovations Hieronymus Fracastorius (France) – The first to discussion the phenomenon of contagious infection

Microscopes Hans and Zacharias Janssen – made the first compound microscope Robert Hooke – First observed cells (cork) – Used a compound microscope that could magnify X.

Animalcules Anton van Leeuwenhoek – developed a microscope that could magnify over 200 X. – He was the first to observe the bacteria, protists, and other organisms. – He called these organisms animalcules. – He was considered crazy by fellow citizens

Maxine Kumin, The Microscope [ the full text of from Kumin’s 1963 children’s book ]: Anton Leeuwenhoek was Dutch He sold pincushions, cloth, and such. The waiting townsfolk fumed and fussed As Anton’s drygoods gathered dust. He worked, instead of tending store, At grinding special lenses for A microscope. Some of the things He looked at were: mosquitoes’ wings the hairs of sheep, the legs of lice, the skin of people, dogs, and mice; ox eyes, spiders’ spinning gear, fishes’ scales, a little smear of his own blood, and best of all, the unknown, busy, very small bugs that swim and bump and hop inside a simple water drop. Impossible! Most Dutchmen said. This Anton’s crazy in the head. We ought to ship him off to Spain. He says he’s seen a housefly’s brain. He says the water that we drink is full of bugs. He’s mad, we think! They called him dumkopf, which means dope. That’s how we got the microscope.

First Scientific Experiment Francesco Redi

Redi Experiment Covered jar proved that maggots did not arise spontaneously Critics felt that the flies on the meat with the netting were a result of Abiogenesis Theory still not proven

Disproving Redi John Needham – boiled chicken broth to kill all of the microorganisms. Sealed the container, and waited. – Microorganisms grew a few days later, proving to him and several others that spontaneous generation did occur

Biogenesis counter experiment Modified Needham's experiment 1750's - Lazzaro Spallanzani – chicken broth in flasks were sealed, the air drawn off with a vacuum, then boiled. – No microorganisms grew. – spontaneous generation supporters argued that spontaneous generation could only occur in the presence of air. – John Needham said that Spallanzani destroyed the vital force and that this experiment proved nothing – Spallanzani is credited with developing canning – food preservation that changed how the world ate and lived.

Handwashing by Physicians Ignaz Semmelweiss - – Forced doctors to wash hands before and after touching patients. – He observed the transfer of childbed fever by doctors that did not wash their hands.

Academy of Science in Paris To put an end to the debate between the two factions, the acadamy offered a prize to the scientist who could finally prove (or disprove) Biogenesis. Louis Pasteur did this. Task – Read the article describing the experiment and answer the worksheet.