Darwin was fascinated by islands The flora and fauna of the recent volcanic Galapagos islands provided several hints towards evolutionary arguments Many of the species were distinct but all were relat

Darwin's fascination with islands led him to observe the distribution of animals and plants in time and space, which provided compelling evidence for the theory of evolution. He also challenged the traditional theory of classification, arguing that the hierarchy of taxonomic groups was merely a pragmatic arrangement and did not reflect any necessary condition of the living world. Instead, the theory of evolution predicted a hierarchical arrangement of taxonomic groups as a consequence of sequential divergence from common ancestral forms, with extinction. Furthermore, attempts at an absolute definition of the species category were doomed to failure due to the continuous emergence of new species from divergence between varieties.