Building a Digital Ark

Imagine the size of the ark that a modern-day Noah would need if he wanted to preserve the planet's 6,000 threatened species of animals, plus some 33,000 similarly imperiled plants. Then add to them the untold millions — perhaps hundreds of millions — of other fauna and flora species that live on the earth. Such a vessel would have to be as big as, well, the planet itself.

But just such a record of the natural world — a collection of images, sounds and words of and about living things, dubbed ARKive — is being assembled in the...