The Origin of the First Life Forms Flashcards
A Greek philosopher that believed that with a favorable environment and forces of nature, life can come from non-living materials
Aristotle
This theory is also known as Spontaneous Generation.
Abiogenesis Theory
This theory states that life could appear from a non-living material
Abiogenesis Theory
An Italian physician that conducted an experiment that changes the idea of Spontaneous Generation
Francisco Redi
An Italian physician that was able to prove that organisms do not just come to life spontaneously
Francisco Redi
What year did Francisco Redi conduct his experiment?
1886
An English Priest and Biologist that challenged Redi’s experiment.
John Needham
An English Priest and Biologist that tried to prove that Spontaneous Generation can occur in appropriate conditions.
John Needham
What year did John Needham challenge Redi’s experiment and conduct his own?
1748
What happened in John Needham’s experiment?
- Heat could kill the organisms, even the smallest ones
- When the broth was boiled, all organisms in it had died from the heat
- Days later, he noticed that a thick solution had formed in the broth
An Italian scholar and scientist that conducted an experiment to verify Needham’s setup.
Lazzaro Spallanzani
What year did Lazzaro Spallanzani conduct his own experiment?
1767
What significant errors did Lazzaro Spallanzani find in Needham’s experiment?
- Needham had not heated the broth enough to kill all organisms in it
- Needham had left the flasks open as they cooled, exposing them to air
What happened in Lazzaro Spallanzani’s experiment?
- The setup that was sealed remained free from microbial growth
- He concluded that life occured from something that entered the unsealed flask and that it was the one responsible for life to grow
This scientist concluded that life occured from something that entered the unsealed flask and that it was the one responsible for life to grow
Lazzaro Spallanzani
This French chemist convinced most scientists that spontaneous generation could not occur.
Louis Pasteur
He made an experiment to test the idea that a vital element from air was necessary for life to emerge
Louis Pasteur
What happened in Louis Pasteur’s experiment?
- He boiled sugar solution with yeast in the flask with long neck
- Eliminated the contaminants through heating
- The flask was left open to allow the vital factor in the air to enter but no organisms develop in the mixture
- It was because the microorganism only settled on the bottom of the curced neck of the flask and could not reach the mixture
“Maggots in the flask”
Francisco Redi
“Boiled broth to kill organisms in it but kept the container open”
John Needham
“Redo John Needham’s experiment but with a different setup”
Lazzaro Spallanzani
“Curved neck setup”
Louis Pasteur
What year was Louis Pasteur’s experiment conducted?
1859
