question: What reason did David Quammen believe that On the Origin of Species was weakened in later editions ?
answer: Darwin making concessions and adding details to address his critics
turker_answer: David Quammen believed that On the Origin of Species was weakened in later editions because Darwin making concessions and adding details to address his critics .
rule-based: David Quammen believed Darwin making concessions and adding details to address his critics that On the Origin of Species was weakened in later editions .