Spontaneous Generation Debate

• some forms of life could arise from nonliving matter people commonly believed that toads, snakes, and mice could be born of moist soil; that flies could emerge from manure; and that maggots (which we now know are the larvae of flies)could arise from decaying corpses.
• Francisco Redi debunked it in 1668 if jars with meat were sealed, no maggots appeared. Air is also not a factor since no maggot growth was found jar sealed with gauze
• John Needham found that even after he heated chicken broth and corn broth before pouring them into covered flasks, the cooled solutions were soon teeming with microorganisms and claimed microbes developed spontaneously from fluids
  • Lazarro Spallanzani heated flasks after sealing, but people said no growth occured because he excluded some "vital" force with the sealing

Biogenesis

• Rudolf Virchow challenged spontaneous generation, hypothesizing that living cells arise only from preexisting living cells. He has no proof so the debate continued until 1861, when Louis Pasteur resolved it
• Pasteur demonstrated that microorganisms are present in the air and can contaminate sterile solutions, but that air itself does not create microbes
• Pasteur's experiment (p. 8, Tortora et al.)