Reports that Revive and Restore is funding an effort to bring back the extinct passenger pigeon -- and other species -- brings to mind Stephen King's 1983 horror novel "Pet Sematary," in which a cat and a boy are brought back to life after being buried in a Native American burial ground. They're indeed back in the land of the living, but they're not quite right.

Or perhaps "Jurassic Park," though re-creating dinosaurs wouldn't be possible even with today's advanced genomic technologies.

Because a full DNA profile of the extinct pigeon doesn't exist, the passenger pigeon genome would be mixed with DNA from the band-tailed pigeon to re-create the passenger pigeon, a species that once numbered in the billions until becoming extinct in the early 20th century. Without the full genome, though, those who argue against "de-extinction" say it would be a new bird and not the passenger pigeon of old.

Those against de-extinction also say efforts to conserve habitat and endangered species are more important, considering the earth to be in the midst of a sixth mass extinction, primarily caused by humans and climate change.

One of the biggest challenges of reviving an extinct animal -- even a close facsimile -- is where to put it. Is there a habitat that will support a new passenger pigeon? What about a re-created wooly mammoth -- also on the list of candidates for de-extinction -- now that its former habitat of grassy steppes has become tundra. The chances are great, experts say, that de-extinct animals would quickly become extinct again.


Proponents counter that the genomic technologies they're developing can be used to help in the recovery of endangered species. That may be the best argument for the pursuit of de-extinction, but only if the two camps can find a way to work together and if de-extinction isn't seen as just an end in itself.

And if the de-extinction movement helps bring more attention to the possibility we truly are experiencing another mass extinction -- one that could ultimately threaten man's future -- so much the better.