Assertion: sign language's relation | /r/HasProperty | recovered
Facets:
value: because of limitations on the methods
type: CAUSE
value: no longer
type: TEMPORAL
Source sentences:
text: Researchers on the evolutionary origin of language generally find it plausible to suggest that language was invented only once, and that all modern spoken languages are thus in some way related, even if that relation can no longer be recovered ... because of limitations on the methods available for reconstruction.