Pandemics in Time

By geo_teacher

  • From Eggs to Life

    William Harvey concluded that all animals, including mammals, develop from eggs, and spontaneous generation of any animal from mud or excrement was an impossibility.

  • Spontaneous Flies

    1668 – Francesco Redi disproved spontaneous generation by showing that fly maggots only appear on pieces of meat in jars if the jars are open to the air. Jars covered with cheesecloth contained no flies.

  • Natural Selection

    Charles R. Darwin and Alfred Wallace independently proposed a theory of biological evolution ("descent through modification") by means of natural selection. Only in later editions of his works did Darwin used the term "evolution."

  • Raw Materials of Life

    Aleksandr Oparin proposed that the Earth's early atmosphere contained methane, ammonia, hydrogen, and water vapor, and that these were the raw materials for the origin of life.

  • The First Antibiotic, Penicilin

    Alexander Fleming discovered the first antibiotic, penicillin

  • Double-Helix Structure for DNA

    James D. Watson and Francis Crick published a double-helix structure for DNA, with one sugar-phosphate backbone running in the opposite direction to the other.

  • Dolly the Sheep

    First clone of an adult mammal