Harry Potter and Stars Wars aren’t real, but Jurassic Park may soon be. Well, kind of. Dinosaurs aren’t coming back because they’ve been extinct for too long (66 million years) for their DNA to survive (it only lasts about a million years or less). But, the woolly mammoth might be a candidate, along with the passenger pigeon and other species we wiped out. Given that we killed them off, do we have a responsibility to bring them back if we can? It’s certainly an admirable aspiration, but before we pave the road to hell with our good intentions, we should probably not bring back the woolly mammoth. Not that there isn’t a role for de-extinction efforts, but it might be useful to develop narrower criteria for which species to bring back.
Douglas McCauley at UC Santa Barbara does just that in a recent paper in the journal Functional Ecology. He isn’t against de-extinction, just not for woolly mammoths, as they don’t meet his three criteria for which species would make the best candidates. First, when woolly mammoths first inhabited North America, they largely roamed on grassland. But, due to changes in soil pH, it’s unlikely that those grasslands would return, meaning that they wouldn’t serve a clear, irredundant ecological function. Also, since woolly mammoths have been gone for thousands of years, it’s not clear that they would actually enhance the ecosystem, and might actually hurt it like invasive species. Third, since mammoths first became extinct due to conflicts with humans, this might happen again, making it unlikely that there will be enough to form an abundant population, with him citing how “The high frequency of elephant-human conflict in Africa provides some indication of how poorly humans and proboscideans co-exist even in rural settings.”
On the other hand, Dr. Beth Shapiro, an evolutionary biologist at UC Santa Cruz, might disagree, as she has said that the woolly mammoth is a “great choice” for de-extinction because of her belief that it would inspire people to be interested in science and also because it would be good for the environment, as woolly mammoths might help recreate grasslands that can insulate the tundra’s permafrost and keep it from releasing greenhouse gases as it melts. However, despite Dr. Shapiro’s expertise in this, I would still err on the side of caution and not try to recreate the woolly mammoth, both for the reasons Dr. McCauley brought up and also because I don’t think the inspirational effects would be enough to counteract the potential ecological damage done by an invasive species of that size.
To be sure, this concern of mine isn’t imaginary, as some Colombian drug lord smuggled in hippos to his country, and the hippos then proceeded to wreck the ecosystem. So, how do we know that bringing back the mammoth, another large mammal, won’t do the same? Also, it’s worth pointing out, as Dr. Shapiro does, that the mammoth we bring back wouldn’t exactly be a mammoth. We would likely use elephant cells as a starting point and edit the genomes to give them mammoth like traits, but the resulting creature would be a mammoth-like elephant, not a mammoth. So, if hippos from Africa couldn’t fit into Central America, how would a mammoth-like elephant from Asia fit into North America? It wouldn’t. Also, I understand that once the technology exists, it will be hard to turn back. De-extinction will be used, but I just want it to be used in a more restricted manner. For example, while the woolly mammoth shouldn’t come back, Dr. McCauley offers examples of species that would be better candidates, such as the Christmas Island pipestrelle bat, which only went extinct four year ago, and which would meet all three of his criteria.
Our impulse to restore lost biodiversity and undo some of the carnage our species has subjected the planet to is indeed noble, but we must approach this challenge soberly. This isn’t an either/or situation, where we either have de-extinction or we don’t. We can still use that same genome editing process to reintroduce lost diversity in species like the white rhino, whose genetic homogeny threatens to destroy its existence. Also, if we think a species is about to go extinct, we can try to sequence its DNA before it does, so that if we do try to “de-extinct” it, we can end up with the actual thing, instead of weird mammoth looking elephants. De-extinction will be reality one day, and instead of fighting it, we should manage its risks so it can yield the environmental benefits promised by advocates without seeing adverse consequences like those with the Colombian hippos, or worse, Jurassic Park.
McCauley, et al.,September 12, 2016. A mammoth undertaking: harnessing insight from functional ecology to shape de-extinction priority setting, Functional Ecology (no volume pages because version of record is available online, but hasn’t been physically published yet)
Interview with Dr. Shapiro (opposing view):
Environmental Benefits of Wooly Mammoth de-extinction: