Islands, in both the literary meaning of land surrounded by sea and the metaphorical sense of anything isolated and surrounded by something else, have played a significant part in the evolution process and in our understanding of it. Islands' isolation allows for quick evolutionary changes and the emergence of new species, allowing evolution to conduct "pilot" experiments that are difficult to conduct on the mainland. And it is because of their modest size that we can better understand and document evolution's processes and products. As a result, the sub-discipline of island biogeography takes pride of place in the study of evolution.
Not surprisingly, both Charles Darwin and Alfred Russell Wallace, co-discoverers of the principle of evolution by natural selection, were island biogeographers before becoming evolutionary biologists, gaining key insights from expeditions to the Galapagos Islands and the Malay Archipelago, respectively.