One of the most important principles in biology is that all living things must come from other living things this principles was not discovered unit the eighteenth century. Before that, people believed that life could come from nonliving mother. For example, they thought that worms could come from meat. Then an Italian scientist named Francesco Red tried an experiment. He covered some meat with a cloth so that flies could not land on it. When no worms grew on the meat, knew that the worms really came from