Dear EarthTalk: What is the “de-extinction” movement all about? Is it really now possible to bring back wildlife species from the dead?
—Bill Mitchell, New York, NY
De-extinction—bringing back extinct animal and plant species—is a term that conservation biologists and environmentalists have been bandying about for a decade or so. But only recently have advances in genetic sequencing and molecular biology transformed de-extinction from theory into something that we are all likely to see in our own lifetimes.
Or so Revive & Restore, a project of the Stewart Brand’s California-based non-profit Long Now Foundation, likes to think. The group is creating a movement around de-extinction, and is taking the lead on efforts to bring back the passenger pigeon while helping out on other ongoing efforts to restore other extinct species including European aurochs, Pyrenean ibexes, American chestnut trees, Tasmanian tigers, California condors, even wooly mammoths.
The main rationale behind bringing back these long gone species and others is to preserve biodiversity and genetic diversity, undo harm that humans have caused in the past, restore diminished ecosystems and advance the science of preventing extinctions.
While de-extinction may seem only theoretical at this point, biologists are already knocking on its door. In 2003, Spanish researchers used frozen tissue from the last Pyrenean ibex, which had died three years earlier, to clone a new living twin (birthed by a goat). While the baby ibex died of respiratory failure within 10 minutes of its birth—a common problem in early cloning efforts—the de-extinction movement was officially born.
Revive & Restore expects to see much more progress in the coming decade given the recent focus on the topic by geneticists, conservation biologists and environmentalists. The group is working with researchers around the world to put together a list of “potentially revivable” species. Some of the criteria for whether a given species is a good candidate for revival include how desirable it would be to have it around, how practical it would be to bring it back, and whether or not “re-wilding” (returning it to a natural environment) would be possible.
First up for Revive & Restore is the passenger pigeon, which was hunted from a population of billions in the 19th century to extinction by 1914. The group has enlisted the help of bird experts around the world to contribute to the project, and in February 2012 convened a meeting at Harvard University to coordinate the next steps. Currently Revive and Restore is busy sequencing the DNA of the passenger pigeon’s nearest living relative, the band-tailed pigeon, and is simultaneously gathering DNA from some 1,500 preserved passenger pigeon specimens. The group hopes to combine this biological and genetic material to reintroduce the once abundant species.
In response to critics who question the logic of bringing back extinct species in a world potentially unprepared to host them, Brand, founder of the Whole Earth Catalog, counters that it’s our job to try to fix “the hole in nature” we created. “It’s our fault that some of these crucial species have been completely wiped out, so we should dedicate our energy to bringing them back,” he says. “It may take generations but we will get the wooly mammoth back.”