History of scientific thought regarding the origins of life and disease. Cell theory, which states that all cells come from other cells and are the basic units of life, was developed over several centuries by scientists like Robert Hooke, Matthias Schleiden, Theodor Schwann, Robert Remak, and Rudolf Virchow. The endosymbiotic theory explains the evolution of eukaryotic cells from ancestral bacteria and is supported by the work of Konstantin Mereschkowski, Ivan Wallin, and Lynn Margulis. In contrast to the prevailing miasma theory, which attributed disease to particles from decomposing matter, the germ theory of disease was established through the work of scientists like Ignaz Semmelweis, John Snow, Louis Pasteur, Joseph Lister, and Robert Koch, ultimately demonstrating that microbes cause disease.