Why can’t we bringing back the moa?
Kiwi scientists have taken a hard look at de-extinction and again remind us the weird concept isn’t as straightforward as movies such as Jurassic Park would have us believe.
In a special issue of the scientific journal Functional Ecology, New Zealand and Australian researchers have reviewed the literature around de-extinction and whether resurrecting long-gone species like the moa could become a reality.
Writing in an editorial, Otago University’s Professor Philip Seddon says any de-extinction efforts would likely focus on recently extinct species whose return would have clear conservation benefits.
That might rule out more ancient extinctions such as the woolly mammoth and moa, which Labour MP Trevor Mallard in 2014 wildly proposed could be resurrected, gaining widespread attention.
In a perspective paper, University of Canterbury scientists say attention should be paid to the genetic issues likely to go hand-inhand with deextinction. Being able to bring back a large enough population to avoid issues such as inbreeding depression would be needed to avoid the peril of “re-extinction”.
In another paper, University of Queensland scientists say modelling tools could help weigh up the pros and cons of de-extinction. The prospect of resurrecting species through cloning or genetic reconstruction through tools such as CRISPR geneediting had caught the imagination of scientists and the public alike.
“However, while the idea of resurrecting mammoths, for example, might hold a ‘ wow-factor’ appeal, efforts would likely be better directed instead towards species where the conservation benefits are clearer,” Seddon said.
“The ecological niches in which mammoths, or moa for instance, once lived, no longer exist in any meaningful way.”
While the moa was hunted to extinction hundreds of years ago, a better candidate could be huia, New Zealand’s largest wattlebird, wiped out in the early 20th century due to factors including over-hunting for natural history collections and a fashion craze for its feathers.
Instead, using cloning techniques to re-establish “proxies” of species that have recently become extinct should be the focus, with determined efforts to prevent endangered species dying out in the first place. “The money and considerable effort required to resurrect, re-introduce, and manage in the wild, viable populations of once-extinct species means there will inevitably be fewer resources available to manage threats facing the very many species that are currently at risk of dying out, but could still be saved,” Seddon said. He suggested de-extinction projects would inevitably be pursued. “The reality of the idea is too sexy to ignore, and it could be driven by aesthetic, commercial, scientific, or some other hitherto unanticipated imperatives and motivations.”
A paper co-authored by the University of Canterbury’s Dr Tammy Steeves highlighted the perils of resurrecting species using only a few, genetically similar individuals.
“Simply put, the more genetic diversity a species has, the more likely it is that it will be able to adapt to a changing environment,” Steeves said. And it was vital to consider the ability a species has to adapt to change.
“Also, small populations that lack genetic diversity are in danger of spiralling to the point of reextinction. This scenario is called the re-extinction vortex,” she said.
Seddon concluded two principal messages arose from the articles.
“The first is that the risks and the uncertainties involved will be hugely reduced . . . if de-extinction candidates are drawn from the most recent extinctions,” he said.
“Second, and perhaps most importantly, extinction of any species marks a significant threshold that once crossed, cannot be fully reversed, despite the apparent promise of powerful new techno
logies.”