_:b663967053 "ISBN:978-0674639416" . _:b663967053 . _:b663967053 "Heterochronous homology that is produced by a retention in adults of a species of traits previously seen only in juveniles." . _:b663967053 . _:b663967053 . _:b663967053 . _:b663967053 . _:b663967053 . _:b663967053 .