Travel Reference
In-Depth Information
volcanic eruptions and tectonic shifts that has produced this biological Mag-
inot Line.
The world knows Alfred Russel Wallace for his proposal, independently of
Darwin, that evolution has taken place through natural selection—though of
course it was Darwin who originated that memorable term. But there were in
fact many dif erences between their views of evolution. One important dif er-
ence was that Wallace emphasized that selection would result in the survival
or extinction of entire races of animals or plants, while Darwin emphasized
the accumulating ef ects of natural selection on populations of individuals.
Like Darwin, Wallace spent years piling up information about the natu-
ral world before he had his great insight. From 1854 to 1862 he explored the
Malay Archipelago, collecting animals and plants and—unlike the indepen-
dently wealthy Darwin—selling many of them to support his travels.
It was immediately clear to Wallace, when he crossed from Borneo or
Bali in the west to Sulawesi or Lombok to the east, that the animals, plants,
and birds changed utterly. His describes the transition vividly in
The Malay
Archipelago
(1869):
The great contrast between the two divisions of the Archipelago is nowhere so abruptly
exhibited as on passing from the island of Bali to that of Lombock, where the two regions are
in closest proximity. In Bali we have barbets, fruit-thrushes, and woodpeckers; on passing
over to Lombock these are seen no more, but we have abundance of cockatoos, honeysuck-
ers, and brush-turkeys, which are equally unknown in Bali, or any island further west. [I was
informed, however, that there were a few cockatoos at one spot on the west of Bali, showing
that the intermingling of the productions of these islands is now going on.] The strait is here
fi fteen miles wide, so that we may pass in two hours from one great division of the earth to
another, dif ering as essentially in their animal life as Europe does from America. If we travel
from Java or Borneo to [Sulawesi] or the Moluccas, the dif erence is still more striking. In the
fi rst, the forests abound in monkeys of many kinds, wild cats, deer, civets, and otters, and
numerous varieties of squirrels are constantly met with. In the latter none of these occur; but
the prehensile-tailed Cuscus is almost the only terrestrial mammal seen, except wild pigs,
which are found in all the islands, and deer (which have probably been recently introduced)
in [Sulawesi] and the Moluccas. The birds which are most abundant in the Western Islands
are woodpeckers, barbets, trogons, fruit-thrushes, and leaf-thrushes; they are seen daily, and
form the great ornithological features of the country. In the Eastern Islands these are abso-
lutely unknown, honeysuckers and small lories being the most common birds, so that the
naturalist feels himself in a new world, and can hardly realize that he has passed from the one
region to the other in a few days, without ever being out of sight of land.
