Sky Islands: Lost & Found Worlds
Cape Melville 'sky island' (credit: Conrad Hoskin, JCU)
A feature of biogeography is that odd creatures evolve on islands. Charles Darwin and Alfred Wallace discovered this fact of natural selection while investigating strange plants and animals in the Galapagos and Borneo. Their discoveries led to a central tenant in evolutionary biology:
"Islands" can be surrounded by water, savannas, deserts, or even boulders but a defining characteristic is that organisms living there are separated by distances and an inability to disperse to surrounding areas. This separation allows evolution to create unique organisms that often have odd characteristics."
Amazing discoveries are still being made in 'lost worlds' on top of isolated mountains. Conrad Hoskin, of James Cook University in Queensland, has been investigating unknown species on a 'sky island' in the far north of tropical Queensland in Australia. Animals there have been isolated from any related species for millions of years. Hoskin, and colleagues from Harvard University, had to be helicoptered into the isolated mountains of Cape Melville National Park on Cape York Peninsula because access was impossible otherwise. The entire mountain range consists of massive boulders the size of houses piled on top of each other.
Cape Melville NP "Sky Island" forests (credit: Conrad Hoskin, JCU)
Hoskin, a postdoctoral fellow at James Cook, identified a new species like a leaf-tailed gecko and commented: “Finding three new, obviously distinct vertebrates would be surprising enough in somewhere poorly explored like New Guinea, let alone in Australia, a country we think we've explored pretty well."
He might have also commented that the gecko is perfectly camouflaged to its strange and isolated boulder strewn environment. Its skin is mottled perfectly and blends-in with the trees and rocks of its 'island' habitat.
Leaf-tailed gecko, Saltuarius eximius (credit: Conrad Hoskin, JCU)
The field ecologist continued: “The top of Cape Melville is a lost world. Finding these new species up there is the discovery of a lifetime - I'm still amazed and buzzing from it.”
Other discoveries remain to be uncovered in 'lost worlds' elsewhere. Darwin and Wallace would have understood Hoskin's excitement in making these new findings. WHB