An 'island in the sky' shelters new life

A giant rhododendron and a half-inch-long frog; a lost bird of paradise and a spiny, worm-eating, egg-laying mammal. Sound like creatures from another world? That's what the scientists who found them thought, too.

Twelve scientists from Indonesia, Australia, and the United States recently returned from a two-week trek through the Foja Mountains on the island of New Guinea. Their finds have yet to be evaluated and officially classified by experts around the world, but a preliminary count of new species includes one bird, four butterflies, five palms, one flower, four or five mammals, and 20 frogs; close to 40 species in total.

To put that in context, scientists have named and classified 1.5 million species since the introduction of Linnaean taxonomy in 1735. That works out to more than 5,000 species a year for the last 271 years. Scientists estimate that Earth is home to anywhere from 5 million to 100 million species. So why are these 40 new ones such a big deal?

"There does seem to be an endemic biota of this mountain range," says Bruce Beehler, the leader of the Foja expedition. "Forty species is not extraordinary in the raw sense, but [it is extraordinary] that they all came from one place, and we believe that's just the tip of the iceberg."

Mr. Beehler calls Foja an "island in the sky" - a biological community completely separated from its surroundings. Its unique and isolated biological community (or "endemic biota," in biology-speak) makes Foja a kind of natural experiment.

"There are probably hundreds of endemic species in the Foja Mountains," Beehler continues. "The mountain range is very young, maybe 3 or 4 million years old. It was under the sea, then a low rain forest, and then got pushed up" to its present height of 7,218 feet. "It had to be physically colonized by creatures." But where did they come from?

Beehler's expedition was designed to answer that question, he says, "by looking at what's there and trying to find the closest relatives. The fact is, the species we've found seem to have close relatives on New Guinea. The new bird looks very similar to another on New Guinea."

Beehler infers from these similarities that existing flora and fauna on the island colonized the montane (cool, moist, elevated) environment of Foja and became an independent species quite recently in the evolutionary time scale. "We're seeing speciation at a very young age," Beehler says. What you can see is the evolution of life."