Hawaii's 20 surviving species of honeycreeper also evolved from just a few individuals
Compared to seabirds
Honeycreepers are poor fliers
So how did the ancestors of these forest birds and Hawaii's other castaways get here
The answer may be blowing in the wind
Even the gentlest breeze can have a huge impact
Tree ferns stir and release their lightweight spores
Thermal updrafts can carry the spores 30 000 feet into the jet stream
And there are even animals designed to ride these high-altitude air currents
Near-weightless spiderlings are expert ballooners
Catching the wind with their gossamer threads
Like spores they too can hitch a ride on the jet stream
Enduring temperatures of minus 30 degrees centigrade
A spider can cross the breadth of the Pacific in a matter of days
