Question: when did the first tiger appeared on earth
[{'answer': 'about 2.88 million years ago', 'provenance': [{'wikipedia_id': '30075', 'title': 'Tiger', 'start_paragraph_id': 23, 'start_character': 158, 'end_paragraph_id': 23, 'end_character': 186, 'bleu_score': 1.0, 'section': 'Section::::Taxonomy and genetics.:Evolution.\n'}]}, {'provenance': [{'wikipedia_id': '30075', 'title': 'Tiger', 'start_paragraph_id': 23, 'start_character': 0, 'end_paragraph_id': 23, 'end_character': 383, 'bleu_score': 0.7251196319790001, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4867944655880350054}, 'section': 'Section::::Taxonomy and genetics.:Evolution.\n'}]}]