Short answers, pulled from the story.
Archaeological evidence of cooking fires dates to at least 300,000 years ago, though some estimates place the start of human cooking as early as 2 million years ago. The oldest evidence of controlled fire used to cook food, drawn from heated fish teeth in a deep cave, was dated to about 780,000 years ago.
Cooking is the art, science, and craft of using heat to make food more palatable, digestible, nutritious, or safe. Preparing food with heat or fire is an activity unique to humans and is found in all human societies as a cultural universal.
The Columbian Exchange moved foods between the Old World and New World across the Atlantic, profoundly affecting cooking on both sides. New World foods like potatoes, tomatoes, maize, and chocolate reshaped Old World cooking, while Old World cattle, wheat, rice, and other foods changed New World cooking.
Most cooking methods have been known since antiquity, including baking, roasting, frying, grilling, barbecuing, smoking, boiling, steaming, and braising. More recent innovations include microwaving and sous vide, in which food is sealed and cooked in a precise-temperature water bath for longer than normal times.
As of 2021, over 2.6 billion people cook with open fires or inefficient stoves, producing household air pollution that causes 3.8 million premature deaths annually. Cooking meat at high temperature can create heterocyclic amines thought to increase cancer risk, and people who ate beef rare or medium-rare had less than one-third the stomach cancer risk of those who ate it well-done.
Cooking can destroy some nutrients, with vitamin C especially prone to oxidation and loss into cooking water. However, cooking increases the bioavailability of thiamin, vitamin B6, niacin, and folate, and a greater proportion of carotenoids is absorbed from cooked vegetables than from raw ones.
Molecular gastronomy is the scientific study of cooking, a subdiscipline of food science concerned with the physical and chemical transformations that occur during cooking. Contributors include the chemist Hervé This and the physicist Nicholas Kurti.