adaptionist
/əˈdɑpʃ(ə)nɪst/ /əˈdɑpʃənɪst/noun
= adaptationist.
adjective
1 Biology = adaptationist.
2Advocating, practising, or tending towards adaptation.
Origin
Late 19th century; earliest use found in Friends' Intelligencer & Journal. From adaption + -ist.