Puzzled by the living creatures and fossils he encountered on the voyage, he took up the study of species variation when he returned to the UK and ultimately produced his signature work, On the Origin of Species.
由於對航行期間所見的生物及化石分布感到困惑，回國後他才針對物種變異進行研究，最後發表了著名的「物種起源」理論。