As they sailed home about nine months later, this, together with other facts, including what he had heard about Galápagos tortoises, made him wonder about the stability of species.
Cando navegaba de volta á casa uns nove meses despois, isto, xunto con outros feitos, incluíndo o que oíra sobre as tartarugas das Galápagos, fixeron que se preguntase sobre a estabilidade das especies.