Selective breeding has been used for thousands
of years to
(1) develop bacteria that produce human insulin
(2) clone desirable plant varieties
(3) develop viruses that protect against diseases
(4) produce new varieties of domestic animals

the abdomen (less formally called the belly, stomach, tummy or midriff) constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. the region occupied by the abdomen is termed the abdominal cavity. the stomach secretes acid and enzymes that digest food. ridges of muscle tissue called rugae line the stomach. the stomach muscles contract periodically, churning food to enhance digestion. the pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine.

your answer is "the 1950's"