### De-extinction begins

The new tools of synthetic biology, I began, are about to liberate conservation in a spectacular way. It is becoming possible to bring some extinct species back to life.

A project within Long Now called “Revive & Restore” is pushing to make de-extinction a reality, starting with the fabled passenger pigeon and moving on to the woolly mammoth. The project’s director, Ryan Phelan, organized a series of three conferences bringing together molecular biologists and conservation biologists to see if “resurrection biology” is becoming a field and how it might proceed responsibly. (The most viewable of the conferences was “[TEDxDeExtinction](https://longnow.org/revive/tedxdeextinction/)” in Washington DC this March.)

At those conferences we heard about cloning efforts that are already partially successful. Alberto Fernández Arias in Spain temporarily brought back an extinct ibex called the bucardo. Michael Archer, from Australia, reported reviving an early stage embryo of the extinct gastric brooding frog. Using traditional back-breeding, Henri Kerkdijk-Otten, is rebuilding the European aurochs (extinct in 1627) from a variety its descendent modern cattle. William Powell is showing how the nearly extinct beloved American chestnut tree is being brought back by a combination of back-breeding and sophisticated genetic engineering.

Robert Lanza (Advanced Cell Technology), Oliver Ryder (The Frozen Zoo), and Michael McGrew (Roslin Institute) showed miracles that can now be accomplished with advanced cloning and induced pluripotent stem cells. Beth Shapiro (UC Santa Cruz) and Hendrik Poinar (McMaster University) explained how complete genomes are being read from the “ancient DNA” of fossils and museum specimens. George Church (Harvard) spelled out his allele replacement technique that will allow editing the genes from an extinct species into the genome of its closest living relative---from the passenger pigeon into the band-tailed pigeon, for example---thereby bringing back to life the extinct animal.

Ben Novak is working full-time for Revive & Restore on the passenger pigeon and is now in the thick of sequencing work and comparative genomics in Beth Shapiro’s ancient-DNA lab at UC Santa Cruz.

Conservation biologists like Stanley Temple, Kent Redford, and Frans Vera regard de-extinction as “a game-changer for conservation.” On the one hand, it dilutes the stark message “Extinction is forever!” while on the other hand it offers a message of hope that conservation can build on.

I concluded, “The fact is, humans have made a huge hole in nature over the last 10,000 years. But now we have the ability to repair some of the damage. We’ll do most of the repair by expanding and protecting wild areas and by expanding and protecting the populations of endangered species.

“Some species that we killed off totally, we might consider bringing back to a world that misses them.”