The extinction of a species

I came across this picture on Yahoo! and it made me very sad, because of its accompanying description:

The giant Galapagos tortoise known as George lifts his head up during a walk in his protected home in the island chain in this February 5, 2001 file photo.

While scientists search for a mate for 'Lonesome George' -- the last known survivor of a species of Galapagos tortoise -- some say the effort to fend off extinction may be in vain. Even if a mate is found, George has not been interested in reproducing in the past and may not know how, former keepers and others who have worked with him said.

I can't imagine that we're looking at the last survivor of an entire species, and there's nothing much we can do to bring it back from the brink of extinction.