Disproving Spontaneous Generation

  • 1745

    John Needham supposedly kills all life in chicken broth but then shows how microorganisms develop again after the broth is cooled. This acted as evidence that spontaneous generation was true.
  • 1768

    Lazzaro Spallazani repeats Needham’s experiment, this time preventing air from reaching the flask. No microorganisms appeared, proving Needham wrong.
  • 1859

    1859
    Louis Pasteur find out that tiny particles floating in air are microbes that are likely to land on and hence contaminate materials. Louis Pasteur disproves the theory for most scientists by showing how a swan necked flask prevented the particles in air to reach the inside of the flask, preventing the appearance of microbes.
  • 1877

    John Tyndall shows that heat-resistant bacterial spores exist, which disproved certain cases in which microbes nevertheless formed despite the removal of air after boiling.
  • 1668

    1668
    Francesco Redi disproves the idea that maggots could come to life from meat by showing that eggs laid by flies caused the maggots.