自生自灭 Origin — Chinese Character Wiki

zìshēngzìmiè

to run its course

自 zì affixadverb

self

(bound form) self; oneself; one's own; refers to an action done by oneself or to oneself
生 shēng verb

to be born

to be born; to come into being
自 zì affixadverb

self

(bound form) self; oneself; one's own; refers to an action done by oneself or to oneself
灭滅 miè verb

to disappear

to vanish or cease to be; to die out