Unshaken after his earlier cliff-dive as a mathematical lemming during Marcus De Sautoy's fascinating talk on statistics and exctinction, Stewart Brand of the Long Now Foundation and founder of the Whole Earth Catalog takes to the stage with John Brockman and Richard Prum to talk about the concept of De-Extinction.
There is a continuum between endangered to extinct, Brand says, but we have to put DNA in that continuum. We start with declining populations on the near end of the spectrum, followed by those suffering severe bottlenecks or that are extinct in the wild — those that we call "critically endangered" — right through to totally extinct. However, with the "extinct" category we also have to take into account what is left of DNA; with scientific advances in genetics and genome mapping perhaps the category of "extinct" is more fluid that we might have thought. If we see the spectrum in reverse — not in terms of what we are losing, but what we could possibly save — then we can see those facing extinction as recovering, reintroduceable and, in the case of extinct species with extant DNA, revivable. DNA obviously degrades over time, but with DNA recovered from specimens trapped in ice over 750,000 years ago, and genetic science progressing quickly, the question of de-extinction becomes at least open for discussion.
After extensive discussion of the science of genomes and the potential options for de-extinction — notably, the Passenger Pigeon (Ectopistes migratorius) and the Wooly Mammoth (Mammuthus primigenius) – Prum questioned whether the potential scientific processes of de-extinction — including, for example, combining mammoth DNA with Elephants — is genuinely de-extinction. Instead, he calls it a "chimera", although Brand suggests that the term "hybrid" is more accurate — a process that already occurs in nature and analogous to, say, the coyote in the continental United States. This is similar to the breeding programme reintroducing the Peregrine Falcon back into the Eastern continental US, a programme run by falcon breeders and involving breeding the characteristics of the Peregrine falcon back into existence.
So we can, but does that mean we should? Referring to comments left on internet news articles about de-extinction, Brand characterised many opponents as "people who worry nature is somehow fragile", accusing them in somewhat dismissive language as "fretting and hang-wringing". "If there were any problems such a viruses in their base genomes, we'd know about them". When discussing other potential problems, specifically with large predators, Brand says "fence technology is getting better". The panel discussed the possibility of limiting de-extinct animals into "ecosystem zoological parks". I couldn't help but think back to Rosenhead's earlier lecture on scientists poor history of modelling and prediction, as well as the obvious pop culture and sci-fi references.
"Can you talk a bit more about these ethical issues?", asked Hans-Ulrich Obrist, when conversation turns to the de-extinction of hominids. We did, of course, Prum said, experience "multiple species of hominids living simultaneously on the planet. 3-4% of European genome is Neanderthal… [Neanderthals] didn't reach a classical extinction, it reached a sort of genetic melding". So, what would be the purpose of re-introducing pigeons or Neanderthals? Well, Passenger Pigeons died as a result of over-hunting as a cheap source of food for slaves and the poor, so science could fix that problem of the near-future…
In one of the most interesting parts of the discussion, Prum raised what he called ethical choices regarding "beautiful species". Birds, he claims, are "aesthetic agents in their own evolution — each extinction is the end of an art world". He discusses that many aspects of animal behaviours are learnt, not inherited. He takes the example of certain types of birds, who learn not just from their parents but from the wider population. When you taken "teenaged birds" from these species and re-introduce them to an island, you get what he describes as a "Lord-of-the-Flies-effect …they essentially have no culture. Just like human vocal learning, avian vocal learning includes a babbling stage…they produce entirely new aural cultures."