The history of herbalism is closely tied with the history of medicine from prehistoric times up until the development of the germ theory of disease in the 19th century. Modern medicine from the 19th century to today has been based on evidence gathered using the scientific method. Evidence-based use of pharmaceutical drugs, often derived from medicinal plants, has largely replaced herbal treatments in modern health care. However, many people continue to employ various forms of traditional or alternative medicine. These systems often have a significant herbal component. The history of herbalism also overlaps with food history, as many of the herbs and spices historically used by humans to season food yield useful medicinal compounds, and use of spices with antimicrobial activity in cooking i