Ethical considerations

Cloning, stem cell manipulation, genome reconstruction, and genome editing are powerful technologies with significant ethical ramifications when applied to de-extinction. The expense and inefficiency of SCNT, for example, has raised questions about its practicality for resurrecting extinct species.

Perhaps the greatest concern, however, is the potential of those technologies, as well as back breeding, to alter the course of natural history. De-extinction provides an opportunity for humans to rectify past harms inflicted on other species, as well as to expand species diversity. But many extinct species were driven out of existence as a result of habitat loss, and others lived in habitats that have since been altered dramatically. In addition, in the near term, resurrected species would be considered endangered and would therefore require conservation, for which resources often are constrained or lacking. De-extinction, by providing the option to bring species back later, also could have the unintended consequence of condoning extinction and could give impetus to endeavours that threaten biodiversity.

Other concerns include unknowns about the fate of resurrected animals, from the health of cloned individuals to whether the animals would be able to adapt to current environmental conditions and whether they would be able to produce viable offspring. The classification of species revived through back breeding, cloning, or genetic reconstruction, all of which could involve divergence from an extinct species’ original genetic constitution, also remains uncertain. The potential to be leveraged as a means of advancing financial and commercial interests has led some to question the motivation of researchers and companies behind certain de-extinction projects.

Nonetheless, de-extinction has helped fuel important progress in science, building particularly on knowledge in developmental biology and genetics. It also has generated interest in endangered species, with many of the tools of de-extinction also being applicable to conservation of endangered species. The reconstruction of extinct genes could be used, for example, to restore genetic diversity in threatened species or subspecies.