By definition, genetic polymorphism relates to a balance or equilibrium between morphs. The mechanisms that conserve it are types of balancing selection.
b aɪ WORD_BOUNDARY d ɛ f ɪ n ɪ ʃ ə n WORD_BOUNDARY d̠ʒ ɪ n ɛ t ɪ k WORD_BOUNDARY p ɑ l ɪ m ɔ ɹ f ɪ z ə m WORD_BOUNDARY ɹ ɪ l eɪ t s WORD_BOUNDARY t ʊ WORD_BOUNDARY ʌ WORD_BOUNDARY b æ l ə n s WORD_BOUNDARY ɔ ɹ WORD_BOUNDARY iː k w ɪ l ɪ b ɹ iə m WORD_BOUNDARY b ɪ t w iː n WORD_BOUNDARY m ɔ ɹ f z WORD_BOUNDARY ð ə WORD_BOUNDARY m ɛ k ə n ɪ z ə m z WORD_BOUNDARY ð æ t WORD_BOUNDARY k ə n s ɜː v WORD_BOUNDARY ɪ t WORD_BOUNDARY ɑ ɹ WORD_BOUNDARY t aɪ p s WORD_BOUNDARY ʌ v WORD_BOUNDARY b æ l ə n s ɪ ŋ WORD_BOUNDARY s ɪ l ɛ k ʃ ə n WORD_BOUNDARY