The term "would" before "undermine" had been added after writing what is now noted as the first expression of his doubts about species being immutable, which led to him becoming convinced about the transmutation of species and hence evolution.
O termo "minaría" inserido no texto en vez de "minan" foi engadido despois de escribir o que agora se considera a primeira expresión destas dúbidas sobre que as especies son inmutables, o que o levou a convencerse da transmutación das especies e, por tanto, da evolución.