MODULE 8 Flashcards
the theory that non-living things can be transformed into living things. The idea that life arose from non-life more than 3.5 billion years ago. Proposes that first life-forms generated were very simple and gradually became complex.
ABIOGENESIS
the idea that life could appear from inorganic/inanimate substances. Early model for abiogenesis.
SPONTANEOUS GENERATION
WHO PROPOSED SPONTANEOUS GENERATION IN THE 4TH CENTURY?
ARISTOTLE
conducted an experiment (which supported this idea) when he put dirty shirts/rags and wheat grains in an open barrel for 21 days, mice will appear.
Jan Baptista Van Helmont
WHO FIRST challenged the idea of spontaneous generation
Francesco Redi (italian physician, 1668)
WHAT EXPERIMENT? two jars; net covered meat that kept adult flies away had no maggots, open jar contained maggots. spontaneous generation is no longer supported by most because it was learned that maggots came from flies (eggs).
REDI’S EXPERIMENT
living organisms come from other living organisms/living comes from another living thing. Belief that life originates from preexisting life.
BIOGENESIS
WHO challenged Redi’s experiment by doing the broth-boiling experiment
John Needham (english priest, 1748)
WHAT EXPERIMENT? boiled the meat broth that killed the microbes, solutions appeared after boiling, the broth became cloudy and found out that microbes came from non-living things. announced that life had been created from non-life. In reality, he didn’t boil it long enough.
NEEDHAM’S EXPERIMENT
WHO challenged Needham’s experiment
Lazzaro Spallanzani (italian scientist, 1767)
WHAT EXPERIMENT? broth in sealed flask remained clear, while broth in open flask became clouded with microorganisms. unsealed boiled broth flask became contaminated when microorganisms from the air entered
SPALLANZANI’S EXPERIMENT
WHO convinced most scientists that spontaneous generation is false
Louis Pasteur (1861)
This theory is purely a religious concept, acceptable only on the basis of faith. No scientific basis. All the different forms of life that occur have been created by God. This idea is found in ancient scriptures of almost every religion.
THEORY OF SPECIAL (DIVINE) CREATION
life reached this planet from heavenly bodies such as meteorites in the form of highly resistance spores of some organisms
COSMOZOIC THEORY
COSMOZOIC THEORY IS ALSO CALLED…
THEORY OF PANSPERMIA
