Behavioral adaptations are the things organisms do to survive. For example, bird calls and migration are behavioral adaptations. Adaptations usually occur because a gene mutates or changes by accident! Some mutations can help an animal or plant survive better than others in the species without the mutation.
Louis Pasteur in 1860s, proposed germ theory. The theory was based upon the fact that diseases are caused by the microorganisms. He was officially the first to publish his work.
