Editor's note: John D. Sutter is a columnist for CNN Opinion and creator of CNN's Change the List project. Follow him on Twitter, Facebook or Google+. E-mail him at email@example.com. The opinions expressed in this commentary are solely those of the author.
(CNN) -- I almost thought the question was a joke.
Submitted by a reader in response to my recent story on the illegal pangolin trade, it went something like this: Should we be as concerned now as we once were about a rare species disappearing, given that we might be able to use future technology to "Jurassic-Park" an extinct creature back into existence?
Of course not, right? That's such a sci-fi concept. One for Hollywood, not for actual scientific and ethical consideration.
As I learned more about the science of "de-extinction," however, I started to realize how serious that question actually is.
It's not whether we will be able to revive extinct species.
That seems likely, in some form or another.
The debate needs to focus on other areas: "Should we?" and "Where will they live?" And does that change our approach to conservation?
First, a brief introduction to what we know about de-extinction.
In 2003, scientists revived the bucardo, a Spanish mountain goat, from DNA that was frozen before the species went extinct. They implanted a goat egg with bucardo genes and then used a goat-ibex mix as the surrogate parent. The animal that contained once-extinct DNA survived only a matter of minutes, but it was heralded as the first de-extinction on Earth, and researchers are trying again.
Other efforts are underway to revive the passenger pigeon, which was hunted to extinction a century ago, from DNA collected from museum specimens.
I called up George Church, a professor of genetics at Harvard Medical School, and one of the most prominent de-extinction backers, to ask how real this technology is.
"It's already happening," he told me.
The example he gave wasn't a bird or goat.
It was the woolly mammoth.
No one will be able to re-engineer a woolly mammoth that is genetically identical to those that roamed Siberia 10,000 years ago, he said, but we will be able to make something close, likely using elephants as a surrogate. Scientists already have "brought back several mutations (from woolly mammoth DNA) and put them into elephant cells successfully," he said.
Church and others, like Stewart Brand, find these prospects incredibly exciting.
"The fact is humans have made a huge hole in nature in the last 10,000 years. We have the ability now and maybe the moral obligation to repair some of the damage," Brand -- who is founder of the Whole Earth Catalog and is one of our premier thinkers on the environment and technology -- says in a 2013 TED Talk.
"Most of that we'll do by expanding and protecting wild lands -- by expanding and protecting the populations of endangered species. But some species that we killed off totally we could consider bringing back to a world that misses them."
I generally agree with the premise that society should pursue science for the sake of science itself. Look no further than NASA's inventions -- CAT scans, computer microchips, personal water filters -- to understand why that makes some practical sense.
But arguing that de-extinction is to nature what hitting "control+Z" is to changes in a Word document strikes me as potentially negligent.
There are some sins that can't be easily undone.
"In practical terms, in the near future in which action is required, extinction is certainly 'forever,'" writes Paul Ehrlich, a professor at Stanford and founder of the university's Center for Conservation Biology.
There are primarily three reasons for this, as Ehrlich and others have argued:
1. Species need a habitat: Climate change, deforestation and illegal hunting are wrecking entire ecosystems. What's the point in bringing back a pangolin, a weird creature I came to love, if it doesn't have a place to live, or will be hunted again? In a National Geographic podcast, the journalist Carl Zimmer smartly notes that a revived species without a viable habitat could be seen as a "freak show." I asked Church about this and he suggested re-engineering DNA to fit the new ecosystem. Perhaps, but doesn't that sound needlessly complicated compared to protecting what we've got?
2. It's a "moral hazard": As Ehrlich argues in a piece for Yale Environment 360, the prospect of de-extinction science makes protecting the existing environment seem less essential. Again: thinking there's an "undo" button can be dangerous.
3. Have you seen "Jurassic Park?": Any advance in science, especially dealing with ecosystems, has unintended consequences. This is especially apparent in the plot of "Jurassic Park," the 1993 blockbuster in which dinosaurs are brought back from extinction for our amusement -- and end up eating us. Some impacts could be subtler but still significant. Earlier this year, for example, the U.S. Army Corps of Engineers estimated ridding the Great Lakes and Mississippi River basin of invasive Asian carp, which have been known to "dominate" native ecosystems, pushing other species out, could cost billions. Who's to say a de-extinct species wouldn't become a similar nuisance, competing with still-living species?
It's possible to pursue de-extinction science and also not use any future developments as an excuse to shirk on conservation. But we have to remind ourselves that extinction, for now, and likely for the near future, is final, the end, forever. Optimism about whiz-bang research shouldn't be allowed to obscure that basic fact.