Extinct animals may soon be brought back from the dead but at extremely high costs.

A new international study suggests resurrecting dead species might lead to biodiversity loss and harm modern conservation efforts.

Joseph Bennett, co-author of the study and a conservation biologist from Carleton University, said bringing back extinct species offers scientists a chance to "right past wrongs." However, there's also a downside.

"[T]here are many species going extinct every year," said Bennett. "Our resources to help save them are severely limited."

Revive & Restore

The idea of reviving extinct species using genetic techniques, which is known as "de-extinction," has long been considered by biologists.

In 2014, a non-profit project called Revive & Restore sought to bring back the extinct passenger pigeon through the dead animal's museum-specific DNA.

Scientists believe the great passenger pigeon is an ideal candidate because there is a veritable treasure trove of data on the animal. Although this study is still under way, its success would unlock knowledge that could be applied to other extinct species.

Modern Conservation Efforts

Now, the question isn't about whether scientists can successfully restore extinct species back to life. It's about whether they should.

Bennett and his colleagues analyzed detailed calculations on how much it would cost places such as New Zealand and New South Wales to conserve their currently threatened species.

"We used the living ones, with all their costs, as the surrogates for the extinct ones," said Bennett.

For instance, the team used funds for the Chatham Island warbler as analog for the extinct Chatham bellbird. It turns out that conservation for the extinct bellbird would amount to $358,966 in U.S. dollars.

The team argued that given the scarcity in conservation funds, bringing back lost species would potentially cost the extinction of more endangered species today.

If New Zealand brought back 11 of its dead species, the government would have to forego the conservation of 33 other living species to pay the costs of resurrecting extinct ones. In New South Wales, scientists can resurrect five dead species, but at the cost of 42 currently living species.

Bennett said there would be sacrifices.

"Without major increases in budgets, it would be like a one-step forward, two-step back scenario," he said.

Ethical Issues

Not everyone agrees with the cost-effective argument. There's also the issue of ethics, said Ronald Sandler, an associate professor at Northeastern University who wrote an accompanying editorial on the research.

Sandler said de-extinction could lead scientists to believe they could "right past wrongs." In fact, extinct species that were once culturally important or symbolically important may be restored to life.

"It might be reasonable to take extra measures," added Sandler.

Ecologist Ben Novak, who is currently working for the Revive & Restore project, told Popular Science that funding for de-extinction and conservation do not exactly mesh together.

Novak explained some donors are interested in the biotechnology involved in the process of de-extinction, while others donate to endangered species after restoration. He also cautioned against generalizing the situation in New South Wales and New Zealand and applying it across the entire world.

Details of the study will be published in the journal Nature Ecology & Evolution.