Question: when do genetic changes to a population due to mutations become more common
[{'answer': 'more favorable', 'provenance': [{'wikipedia_id': '19702', 'title': 'Mutation', 'start_paragraph_id': 10, 'start_character': 207, 'end_paragraph_id': 10, 'end_character': 221, 'bleu_score': 1.0, 'section': 'Section::::Description.\n'}]}, {'provenance': [{'wikipedia_id': '19702', 'title': 'Mutation', 'start_paragraph_id': 10, 'start_character': 0, 'end_paragraph_id': 10, 'end_character': 278, 'bleu_score': 0.9529077664391161, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11099642151397313498}, 'section': 'Section::::Description.\n'}]}]