National Geographic: “Bringing Them Back to Life”

I met Fernández-Arias last autumn at a closed-session scientific meeting at the National Geographic Society’s headquarters in Washington, D.C. For the first time in history a group of geneticists, wildlife biologists, conservationists, and ethicists had gathered to discuss the possibility of de-extinction. Could it be done? Should it be done? One by one, they stood up to present remarkable advances in manipulating stem cells, in recovering ancient DNA, in reconstructing lost genomes. As the meeting unfolded, the scientists became increasingly excited. A consensus was emerging: De-extinction is now within reach.

It’s gone very much further, very much more rapidly than anyone ever would’ve imagined, says Ross MacPhee, a curator of mammalogy at the American Museum of Natural History in New York. What we really need to think about is why we would want to do this in the first place, to actually bring back a species.

Carl Zimmer

I found this older magazine piece while writing my blog post about the recent mammoth de-extinction initiative. It occurs to me that I forgot to mention one other hurdle on the path to successfully returning an extinct species into the natural environment: the low genetic variability of the resurrected animals, which would make them more susceptible to diseases and environmental changes. This would affect larger animals with slower reproductive cycles in particular, so the challenge of this mammoth project becomes that much more complicated. It is evidently much easier to prevent species from going extinct, and that’s where the majority of our efforts should focus.

As for the fundamental question about ‘why’ we should attempt to de-extinct species, I feel the answer is fairly obvious: either they had some unique genetic traits that we think should be preserved for future evolution, or they played a vital role in the ecosystem. Mammoths qualify on both of these criteria to some extent, while other species are more generic and easily substituted in nature – there are more than enough pigeons on the planet, so I don’t see a reason to prioritize them for revival efforts.

In 1813, while traveling along the Ohio River from Hardensburgh to Louisville, John James Audubon witnessed one of the most miraculous natural phenomena of his time: a flock of passenger pigeons (Ectopistes migratorius) blanketing the sky. The air was literally filled with Pigeons, he later wrote. The light of noon-day was obscured as by an eclipse, the dung fell in spots, not unlike melting flakes of snow; and the continued buzz of wings had a tendency to lull my senses to repose.

When Audubon reached Louisville before sunset, the pigeons were still passing overhead—and continued to do so for the next three days. The people were all in arms, wrote Audubon. The banks of the Ohio were crowded with men and boys, incessantly shooting at the pilgrims… Multitudes were thus destroyed.

In 1813 it would have been hard to imagine a species less likely to become extinct. Yet by the end of the century the red-breasted passenger pigeon was in catastrophic decline, the forests it depended upon shrinking, and its numbers dwindling from relentless hunting. In 1900 the last confirmed wild bird was shot by a boy with a BB gun. Fourteen years later, just a century and a year after Audubon marveled at their abundance, the one remaining captive passenger pigeon, a female named Martha, died at the Cincinnati Zoo.

Earliest published illustration of the species (a male) Mark Catesby, 1731