Travel Reference
In-Depth Information
uted to a wave of extinctions that wiped out almost all of South America's
marsupials. Some marsupials managed to travel the other way, but most of
these escapees eventually went extinct. Only the tough and versatile opos-
sum survived.
At Wallace's boundary, too, placental mammals have been more success-
ful in moving across the line to the east than marsupials have been in moving
to the west. And humans have accelerated this invasion of the placentals, by
introducing deer and monkey species to Lombok and Sulawesi.
The chaotic geology of Indonesia has resulted in an encounter between
highly divergent groups of organisms, one that would not have happened if
Australia and New Guinea had kept moving to the east instead of veering to
the north. Life in this part of the world has survived literally thousands of
geological catastrophes—vast volcanic eruptions, immense tidal waves, and
the crunching descent of great pieces of the Earth's crust into the depths of
the oceans. How, through all this terrifying cacophony, have living things
managed to be so resilient?
Some of them did so by adapting to such extreme conditions. The story
of the megapodes provides one example of life's infi nite resourcefulness.
Danger and opportunity
Australasia's uniqueness is not confi ned to its marsupials and monotremes.
Many of the birds of Australasia, such as the bowerbirds, birds of paradise,
and megapodes, are also found nowhere else on the planet.
Like the hoatzins, the megapodes occupy their own distinct evolutionary
lineage, though they are remotely related to chickens. They are also the only
birds that have taken advantage of the volcanic activity in the Pacifi c's great
ring of fi re to help them reproduce. Megapodes are a poster child for life's
astonishing ability to take advantage of potential disasters.
Megapodes bury their eggs where natural processes like organic decay
or volcanic heat will keep them warm. The parents then wander of to live
carefree megapode lives, while their chicks develop underground. After
hatching the chicks actively dig their way to the surface. From the moment
