It’s been a long time coming, but my NatureTalks: De-extinction event is finally over. And what an evening it was! It began with an engaging conversation with science journalist Ivan Semeniuk of The Globe and Mail regarding the prospect of bringing extinct species back to life. As you can see in the video (below) we spoke about various aspects of de-extinction: possible candidates, the methods involved, and the pros and cons of doing it.
We were restricted to speaking for only 20 minutes (limitations imposed by video playback on the web), so we were able to only briefly touch upon these important subjects. There were also many interesting questions that we didn’t get to cover, but which inevitably came up during our audience discussion afterwards. I thought I would share a few of these with our readers, with the intention of further promoting the dialogue.
Are resurrected individuals truly the same as those that went extinct?
In all this talk of “de-extincting” species, there is often little mention of the fact that the end result (say, a newborn Pyrenean ibex) isn’t 100% authentic. What I mean by this is that de-extinction procedures, such as somatic cell nuclear transfer (cloning), fail to replicate the entirety of the lost genome.
Rather, the reliance upon surrogates to carry the developing embryo to term means that a small percentage of the newborn’s genetic makeup will come from the surrogate mother in the form of mitochondrial DNA (which is inherited maternally). Moreover, the resurrected newborn isn’t likely to exhibit all the same learned behaviours as its extinct ancestors because it has no example to follow. Can we therefore say that we have truly resurrected an extinct species? Are we comfortable with this kind of hybridization?
Are de-extinction efforts viable in the long term?
Congratulations! After hundreds of thousands of dollars in funding and years of painstaking research, you’ve managed to clone an extinct woolly mammoth. Now what? If you were hoping to reintroduce the species to the wild, you’re going to need a lot more than a single individual to make such a project sustainable. A mating pair would be a start, but even then, the long-term outlook seems bleak because the predictable inbreeding between siblings would quickly reduce the fitness of the species.
In fact, you will likely need to resurrect tens or hundreds of individuals to get the genetic variability necessary to maintain a healthy population. This is especially true of such de-extinction candidates as the highly social passenger pigeon, which only initiates breeding when present in high numbers. You might want to apply for more money…
Isn’t extinction normal?
If there’s one thing that the fossil record has taught us, it’s that species come and go all the time. In fact, some 99.99% of all species that ever existed have gone extinct. Put another way: extinction is the norm. Therefore, at what point—if any—should we intervene?
De-extinction advocates would argue that we should focus on bringing back only those species that we have caused to go extinct. But why? Are we not also a part of the natural order of things? Moreover, how culpable must we be before getting involved?
Extinction is a complicated thing, and there are likely many factors involved in the extinction of any one species. If climate change led to the decline of woolly mammoth numbers, and we killed off only the few remaining populations, is the onus entirely on us to bring them back?
The issue of de-extinction can be a divisive one, and I don’t think the answers to many of these questions are simple. People have asked me for my take on the matter, but I’m far from decided. I tend to think we have more important things to worry about (such as species conservation) before we start to re-introduce previously extinct animals to the wild, yet I find the argument about re-establishing biodiversity in otherwise desolate ecosystems to be appealing.
I hope you’ll have fun engaging these questions in the comments section below, or by voting on our online polls. For the reactions of some audience members at the event, watch the video below. In the meantime, I’m going back to studying non-avian dinosaurs, which we have no chance of resurrecting.