Assertion: hoatzin's claw | /r/HasProperty | secondary adaptation
Facets:
value: from its frequent need
type: CAUSE
Source sentences:
text: Modern researchers, however, hypothesize that the young hoatzin's claws are of more recent origin, and may be a secondary adaptation from its frequent need to leave the nest and climb about in dense vines and trees well before it can fly.
text: It is most likely that the wing claws are a secondary adaptation closely linked with the aquatic environment of the species . . . .”28