Our Expert Voices conversation on de-extinction.

Given the worsening biodiversity crisis and severely limited resources for reversing it, we need to act quickly and effectively. De-extinction is not the answer.

The cost: For the money it would cost to bring one species back from extinction and support it in the wild, we could save dozens more species from going extinct. Spending millions on resurrecting one species is a decision not spend it on living threatened species, and allow them to go extinct.

The real risk: Although some have legitimately suggested that we need to be careful introducing genetically-modified facsimiles of long-dead species into the wild, the greatest risk of de-extinction actually lies in wasted effort. Most of the species being mentioned as de-extinction candidates have either lost their habitat forever or would be subject to the same threats that drove them extinct in the first place.

For many conservation issues, we know what we need to do. Eastern forests are threatened by habitat loss and invasive species, not a lack of passenger pigeons. The Arctic is threatened by climate change, and introducing mammoths will not solve this.

Bottom line: De-extinction is a fascinating concept, but in its current form it is not an effective conservation tool.

Other voices in the conversation:

Molly Hardesty-Moore, ecologist, University of California, Santa Barbara: Don't forget an extinct creature's ecology

Ben J. Novak, biologist, The Great Passenger Pigeon Comeback: De-extinction is like any other conservation program

Alejandro Camacho, legal scholar, University of California, Irvine: Wildlife laws aren't ready for the return of extinct species

John Hawks, paleoanthropologist, University of Wisconsin-Madison: Bringing back Neanderthals