▁for ▁investig ating ▁whether ▁a ▁character ▁is ▁adapt ive ▁is ▁known ▁as ▁adaptation ism . ▁Although ▁assuming ▁that ▁a ▁character ▁is ▁functional ▁may ▁be ▁helpful ▁in ▁research , ▁some ▁characteristics ▁of ▁organ isms ▁are ▁non - function al , ▁formed ▁as ▁accident al ▁sp and rel s , ▁side ▁effects ▁of ▁neighbour ing ▁functional ▁systems . ▁ ▁Natural ▁selection ▁ ▁From ▁the ▁point ▁of ▁view ▁of ▁natural ▁selection , ▁bi ological ▁functions ▁exist ▁to ▁contribute ▁to ▁fit ness , ▁increasing ▁the ▁chance ▁that ▁an ▁organ ism ▁will ▁surv ive ▁to ▁reproduce . ▁For ▁example , ▁the ▁function ▁of ▁ch lor oph yll ▁in ▁a ▁plant ▁is ▁to ▁capture ▁the ▁energy ▁of ▁sun light ▁for ▁photos yn thesis , ▁which ▁cont ributes ▁to ▁evolution ary ▁success . ▁ ▁In ▁eth ology ▁ ▁The ▁eth ologist ▁N iko ▁T in ber gen ▁named ▁four ▁questions , ▁based ▁on ▁Arist ot le ' s ▁Four ▁C aus es , ▁that ▁a ▁bi ologist ▁could ▁ask ▁to ▁help ▁explain ▁a ▁behaviour , ▁though ▁they ▁have ▁been ▁general ised ▁to ▁a ▁wider ▁scope . ▁ 1 ) ▁Mechan ism : ▁What ▁mechan isms ▁cause ▁the ▁animal ▁to ▁behave ▁as ▁it ▁does ? ▁ 2 ) ▁Ont ogen y : ▁What ▁development al ▁mechan isms ▁in ▁the ▁animal ' s ▁emb ry ology ▁( and ▁its ▁youth , ▁if ▁it ▁lear ns ) ▁created ▁the ▁structures ▁that ▁cause ▁the ▁behaviour ? ▁ 3 ) ▁Function / ada pt ation : ▁What ▁is ▁the ▁evolution ary ▁function ▁of ▁the ▁behaviour