Endemic forms.
Despite this general poverty of species, island life is distinguished by a great proportion of peculiar or endemic forms, and a tendency toward divergence, which is the effect of isolation and which becomes marked in proportion to the duration and effectiveness of isolation. Isolation, by reducing or preventing the intercrossing which holds the individual true to the normal type of the species, tends to produce divergences.[815] Hence island life is more or less differentiated from that of the nearest mainland, according to the degree of isolation. Continental islands, lying near the coast, possess generally a flora and fauna to a large extent identical with that of the mainland, and show few endemic species and genera; whereas remote oceanic islands, which isolation has claimed for its own, are marked by intense specialization and a high percentage of species and even genera found nowhere else.[816] Even a narrow belt of dividing sea suffices to loosen the bonds of kinship. Recent as are the British Isles and near the Continent, they show some biological diversity from the mainland and from each other.[817]
Paradoxical influences of island habitats upon man.
The influence of an island habitat upon its human occupants resembles that upon its flora and fauna, but is less marked. The reason for this is twofold. The plant and animal life are always the older and therefore have longer felt the effects of isolation; hence they bear its stamp in an intensified degree. Man, as a later comer, shows closer affinity to his kin in the great cosmopolitan areas of the continents. More than this, by reason of his inventiveness and his increasing skill in navigation, he finds his sea boundary less strictly drawn, and therefore evades the full influence of his detached environment, though never able wholly to counteract it. For man in lowest stages of civilization, as for plants and animals, the isolating influence is supreme; but with higher development and advancing nautical efficiency, islands assume great accessibility because of their location on the common highway of the ocean. They become points of departure and destination of maritime navigation, at once center of dispersal and goal, the breeding place of expansive national forces seeking an outlet, and a place of hospitality for wanderers passing those shores. Yet all the while, that other tendency of islands to segregate their people, and in this aloofness to give them a peculiar and indelible national stamp, much as it differentiates its plant and animal forms, is persistently operative.
Conservative and radical tendencies.
These two antagonistic influences of an island environment may be seen working simultaneously in the same people, now one, now the other being dominant; or a period of undisturbed seclusion or exclusion may suddenly be followed by one of extensive intercourse, receptivity or expansion. Recall the contrast in the early and later history of the Canaries, Azores, Malta, England, Mauritius and Hawaii, now a lonely, half-inhabited waste, now a busy mart or teeming way-station. Consider the pronounced insular mind of the globe-trotting Englishman, the deep-seated local conservatism characterizing that world-colonizing nation, at once the most provincial and cosmopolitan on earth. Emerson says with truth, "Every one of these islanders is an island himself, safe, tranquil, incommunicable."[818] Hating innovation, glorifying their habitudes, always searching for a precedent to justify and countenance each forward step, they have nevertheless led the world's march of progress. Scattered by their colonial and commercial enterprises over every zone, in every clime, subjected to the widest range of modifying environments, they show in their ideals the dominant influence of the home country. The trail of the Oxford education can be followed over the Empire, east to New Zealand and west to Vancouver. Highschool students of Jamaica take Oxford examinations in botany which are based upon English plant life and ignore the Caribbean flora! School children in Ceylon are compelled to study a long and unfamiliar list of errors in English speech current only in the London streets, in order to identify and correct them on the Oxford papers, distributed with Olympian impartiality to all parts of the Empire. Such insularity of mind seems to justify Bernard Shaw's description of Britain as an island whose natives regard its manners and customs as laws of nature. Yet these are the people who in the Nile Valley have become masters of irrigation, unsurpassed even by the ancient Egyptians; who, in the snow-wrapped forests of Hudson Bay, are trappers and hunters unequalled by the Indians; who, in the arid grasslands of Australia, pasture their herds like nomad shepherd or American cowboy, and in the Tropics loll like the natives, but somehow manage to do a white man's stint of work.