Question: when was it discovered that fingerprints were unique
[{'answer': 'By 650'}, {'provenance': [{'wikipedia_id': '84777', 'title': 'Fingerprint', 'start_paragraph_id': 62, 'start_character': 0, 'end_paragraph_id': 62, 'end_character': 798, 'bleu_score': 0.7097186051013901, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6253483124332154123}, 'section': 'Section::::History.:Antiquity and the medieval period.\n'}]}]