There has always been a morbid fascination with bringing things back from the dead. From Mary Shelley’s Frankenstein to Michael Crichton’s Jurassic Park, the idea of playing God has never been far from our imaginations. But could it really happen? De-extinction: the process of cloning and recreating extinct species (1), may not just be a work of fiction. After all, we’ve all heard of Dr Ian Wilmut’s 1996 trial where Dolly the sheep became the first mammal clone (1), and surely bringing back a long lost species, such as a woolly mammoth (Mammuthus primigenius) (figure 1), can’t be that different… Right?
De-extinction: How does it work?
For all the budding John Hammonds out there, sadly things aren’t so simple. Cloning a sheep and cloning an extinct mammoth couldn’t be less similar: they are fraught with complications (2). While the actual requirements to clone a mammoth appear relatively simple: an intact mammoth genome, an empty egg cell (oocyte) from a viable surrogate i.e. an Asian elephant (Elephas maximus), and a small “zap” of electricity to really add to the Frankenstein atmosphere; these mammoth “ingredients” are hard to come by (1). In 2013, there was a (literally) ground-breaking discovery of a incredibly well preserved 40,000 year-old mammoth carcass in permafrost, which they named “Buttercup”, and which could hold the vital, intact mammoth genome scientists have been looking for (figure 2) (2). Although, this is unfortunately unlikely due to the rather fragile nature of DNA, since freezing and subsequent thawing causes damage to the cells and its genetic contents (2).
The bare bones: Genetics
In an ideal world, where viable, intact DNA is found, that is only the first hurdle in this mammoth task. Next, the mammoth DNA needs to be placed in the empty egg cell of a related species, the closest of which being the Asian elephant, a species classed as endangered by the IUCN red list (3). Obtaining egg cells from this species has never actually been accomplished, and risks the safety of many Asian elephants egg-donors to refine the technique before a mammoth embryo would even be viable (3). Even then, the chances of the embryo being accepted by the surrogate, and both mother and calf surviving to full term, is extremely slim (2).
To remedy this, the Long Now Foundation (LNF), a group of scientists behind projects to bring back the woolly mammoth and the passenger pigeon (Ectopistes migratorius), are hoping to create an Asian elephant/woolly mammoth hybrid (1). Genetically, this was achieved earlier this year by splicing mammoth DNA into the genome of an Asian elephant, hopefully reducing the need for a perfectly intact genome and increasing the chances of the surrogate accepting the embryo (figure 3) (1). Once cloned successfully, the mammoth, they argue, would be a perfect grassland engineer for the Pleistocene Park in Russia, and could help to restore the tundra back to how it used to be before the permafrost started melting and contributing to climate change (4). This is an extremely attractive argument since, with enough mammoths (4), de-extinction could be a potential benefit to the world by helping to combat climate change… Incidentally, something Daphnia could (potentially) also do.
The final hurdle: Ethics
Once the seemingly endless practical issues have been resolved, what about the ethical issues? Is this new mammoth actually going to be a mammoth when all’s said and done (3)? What value would this lone mammoth have (1)? After all, it won’t live like a wild mammoth, it won’t learn mammoth behaviours from its parents, and would perhaps be condemned to life in a poorly resourced zoo (3). And what about its quality of life (5)? It would be the subject of endless testing and monitoring, and with the constant risk of being killed by illegal trophy hunters, it could never be truly wild (1). Even if enough mammoths are cloned and released into the wild, they might not adequately fulfil the task planned for them by the LNF, and using clones could potentially lead to lethal genetic mutations from inbreeding (1). One step forward, two steps back, perhaps. So what would the point really be? To inflict our endeavours on a creature that would realistically be doomed to live a solitary existence in the frozen north, or a cramped zoo, all in the name of science?
So what’s the point?
The answer could be absolution. As a species, we are plagued with the guilt of causing so many extinctions, and driven by the very human desire to rectify what we’ve done (4). But sadly, there’s nothing we can do, and the best thing we can do is learn from our mistakes, not try to bring back the past (4). It’s a crying shame that species such as the Tasmanian Tiger (Thylacinus cynocephalus) and the passenger pigeon aren’t here anymore, but they’re lessons to learn from before we run out of time for the many more species that we could lose in a matter of years (1). That should be the focus rather than the need to play God. By what right and what criteria can we choose which species are resurrected and which remain in the history books (5)? As tempting as it is, they won’t solve our problem, we need to focus on conserving what we have and focus on the now, not provide ourselves with a failsafe for our mistakes (1).
Even though the human race has many skeletons in its closet, de-extinction will not rectify that. Cloning extinct animals is still extremely rare and controversial, making many arguments about this largely speculative about a future we may not even face (5). In the meantime, there are more pressing concerns to tackle before we start considering bringing back fauna of yester-epoch (4), and such thought-experiments could distract us from the threats of extinction and climate change that jeopardise our future: the real elephant in the room.
1. Ogden, L. E., (2014), Extinction Is Forever… Or Is It?, BioScience, 64(6), 469-475.
2. Loi, P., Saragusty, J., & Ptak, G., (2014), Cloning the mammoth: a complicated task or just a dream?, Reproductive Sciences in Animal Conservation, Springer, New York, 489-502.
3. Whittle, P. M., Stewart, E. J., & Fisher, D., (2015), Re-creation tourism: de-extinction and its implications for nature-based recreation, Current Issues in Tourism, (ahead-of-print), 1-5.
4. Salsberg, C. A., (2000), Resurrecting the woolly mammoth: science, law, ethics, politics, and religion, Stanford Technology Law Review, 1, 1-30.
5. Friese, C., & Marris, C., (2014), Making De-Extinction Mundane, PLoS Biology, 12(3), e1001825.