De-extinction may cause extinction

The likely huge costs of re-engineering extinct animals might deprive some of today’s endangered species the help and protection they need to recover. Andrew Masterson reports.    

Will mammoths one day once again roam the earth? And if they do, what will be the real cost?
Dorling Kindersley

The announcement in February this year that a team of geneticists from Harvard were just two years away from producing a mammoth embryo generated renewed focus on the subject of de-extinction – the somewhat clumsy term denoting an engineered return from oblivion for long-gone species.

Bringing back the dead on a species-level scale carries undeniable romantic appeal – even the coldest heart is stirred by imagining skies once again darkened by flocks of passenger pigeons – but research by a team of scientists from Canada, Australia and New Zealand indicates that doing so would probably push several other species over the edge.

Their findings are published in Nature Ecology and Evolution.

The study, led by Joseph Bennett of Carleton University in Ottawa, examined the likely costs of de-extinction projects in Australia and New Zealand under a couple of state and private funded scenarios, and concluded that in almost all cases the modelling “strongly suggests that resources expended on long-term conservation of resurrected species could easily lead to net biodiversity loss, compared with spending the same resources on extant species.”

Money available for conservation projects, the researchers note, is always scarce. Factoring in the high cost of building and maintaining a population of a previously extinct species inevitably means less money available to safeguard existing, endangered ones.

Funding 11 nominated de-extinction targets in New Zealand, for instance, “would sacrifice conservation for nearly three times as many extant species”.

One of the reasons sometimes given for de-extinction projects is that certain resurrected species – mammoths, for example – could be regarded as environment-builders. The re-introduction of such animals, the argument goes, would lead to the revival and reformation of environments impoverished by their absence, thus driving the recovery of other, perhaps threatened, species.

Bennett’s team sound a strong warning about such proposals. “Resurrected ecosystem engineers would be introduced into environments that have been much altered by humans, and they could fail to thrive in these new circumstances,” they write. Equally, they go on to note, such species might also become invasive, destroy environments used by other species, or spread disease.

Only in one scenario – the de-extinction of a single island-dwelling animal – did the researchers find possible benefits to extant species. This was largely coincidental, arising from the fact that efforts to protect the resurrected species from predation by humans or feral invaders would equally protect other residents.

In every analysis, the scientists did not include the costs of the actual genetic engineering and husbandry required to establish the initial colony for a resurrected species, because they are unknown. They note, however, that de-extinction genetic engineering, whether state or privately funded, is likely to be very expensive and that therefore all their modelling should be considered “optimistic”.

In an accompanying opinion piece, Ronald Sandler of the Department of Philosophy at Boston’s Northeastern University warns that cost-benefit analyses of the type done by Bennett’s team should not be “treated as decisive regarding whether a de-extinction ought to proceed.”

He says that the economics of de-extinction should be only one of many factors considered when deciding whether to attempt to resurrect the dead. Others include “cultural value, environmental rights, justice, intrinsic value and aesthetics. “

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