islands. Island-bound mammals, reptiles and amphibians have also shown disproportionate vulnerability. But now that the continental landscapes are being carved into fragments, the island syndrome is coming to the mainlands.

Several studies by William Newmark and other ecologists have shown that some national parks in the U.S., Canada and East Africa have lost populations of mammals to the island syndrome. These have been local extinctions within a given patch of landscape, not extinctions of an entire species; still, they represent ominous warnings of a worldwide trend and must be counted as failures in exactly those places we thought we had protected. If the lynx can't survive within Mount Rainier National Park, in Washington state, where can it survive? If the greater kudu and the sable antelope have vanished from Mkomazi Game Reserve in Tanzania, snuffed out by the bad magic of insularity, then what losses are occurring on those remnants of landscape that haven't received such statutory protection?

The island syndrome challenges one of the most basic assumptions behind humanity's halfhearted efforts at nature conservation: that we can save the rain forest, the dry forest, the panda, the elephant, the multifarious richness of species and ecosystems, by setting aside a few tracts of expendable landscape and calling them parks, nature reserves, refuges.

Truth is, we can't. It won't work. It's not enough. Nature is too interconnected. A species goes extinct, taking another species with it, and the consequences of their absence are felt by still others. When sliced into small pieces, ecosystems lose species and then--like tapestries--they tend to unravel.

Meanwhile, McLuhan's global village is also becoming reality, as advances in communication and travel carry Web sites, rap music, Marlboro ads, American TV and English-speaking tourists to every corner of the planet, pushing local cultures and languages to extinction. That McLuhanesque connectivity, with its homogenizing effect, turns out to be just as destructive, in its own way, as the island syndrome.

The dismal irony of our age is that these two seemingly opposite trends, cultural unification and ecological fragmentation, yield a common result: loss of diversity. The global archipelago will be a world that's starker, uglier, duller and lonelier for us humans as a species, and we'll all experience that loneliness together.

David Quammen is author of The Song of the Dodo