1 [I,T] (formal 正式) to develop or to make sth develop gradually, from a simple to a more advanced form (使)演化,形成:
His style of painting has evolved gradually over the past 20 years.20年来,他的画风一直在慢慢地演变。
2 [I] develop (from sth) (used about plants, animals, etc) to develop over many thousands of years from simple forms to more advanced ones (指生物)进化