Recent advances in genetic science have brought the possibility of cloning extinct animals closer to reality. A recent TEDxDeExtinction conference brought together scientists and ethicists to discuss the resurrection of extinct species, the consensus was that the process is within reach. But should it be done?
Bringing a species back from extinction can be a complicated affair; amongst other procedures it can require obtaining or constructing the entire genetic code of the species, manipulating stem cells, combining all the elements of a fertilised egg and finding an appropriate surrogate to give birth to the individual of a long-lost species. But a movement headed by the California-based project Revive & Restore, and supported by many scientists, says the capability to restore extinct species is here, and now is the time to start using it.
The closest anyone has come to resurrecting an extinct species was in 2003, when a team of French and Spanish scientists revived a wild goat species known as Pyrean ibex, or bucardo,. The species was driven to extinction over centuries of hunting, and the last living individual died in 1999. But her DNA was captured and stored, and the team managed to successfully implant an egg containing her DNA into a goat surrogate. Of many attempts, only one of the cloned individuals came to full term, and was born by cesarean section, only to die minutes later from breathing difficulties as a result of a brain tumour.
Though the achievement of bringing to life an individual of a species completely non-existent for several years previous is astonishing, the sad end to the story of the bucardo highlights one of the issues with resurrecting species. Building a full set of healthy DNA is tricky, often requiring a piecemeal construction of ancient and synthesised DNA, as well as some from similar species, and as a result the individuals may have difficulties from the start.
Many argue against de-extinction, and the health and welfare of the resurrected species is one of their many reasons cited. Some ecologists argue that not enough is known about how the resurrected species will fit into the ecosystem to risk their introduction, and that more attention should be focused on conserving the species that are currently endangered rather than trying to atone for human actions through species resurrection.
The speed at which DNA disintegrates means that species which have been long extinct, such as extinct dinosaurs, are almost impossible to resurrect. But more recently extinct animals such as the giant sloth, the thylacine, the sabre-toothed cat, the woolly mammoth and even that most dead of species, the dodo, are all possible candidates for de-extinction. While the ethics and practicalities of resurrecting such species will continue to be debated, the science will move forward to more accurate and reliable levels, and perhaps the future will see the return of animals from our past.
