Question: who figured out the mechanism of evolution known as natural selection
[{'answer': 'Charles Darwin', 'provenance': [{'wikipedia_id': '21147', 'title': 'Natural selection', 'start_paragraph_id': 1, 'start_character': 232, 'end_paragraph_id': 1, 'end_character': 246, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '21147', 'title': 'Natural selection', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 329, 'bleu_score': 0.755195747975081, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15255686231342267095}, 'section': 'Section::::Abstract.'}]}]