Today, NPR's Studio 360 featured a story on de-extinction, the "resurrection" of extinct animals using cloning or, in attempts to "revive" the recently extinct wild forebears of domesticated animals, back breeding.
Last month, "Just Alison" wrote an excellent article about the ethics of de-extinction on her indispensible Biodiversity Revolution blog. She concentrates on the "de-extinction" of the wooly mammoth, which has been proposed (mammoth DNA would be implanted in the ova of extant elephants). In their wonderful book Carnivorous Nights: On the Trail of the Tasmanian Tiger my friends Margaret and Michael (I swear, I'm not being biased, the book is great) touched on efforts to revive the thylacine by implanting DNA into the ova of Tasmanian devils.
I am somewhat torn on the issue of de-extinction. While it would be cool to have passenger pigeons or Carolina parakeets back, any "resurrected" species would be mere simulacra of the extinct species whose DNA (probably "repaired" in the lab due to degradation of the DNA in preserved specimens) their somatic cells bear (never mind the fact that they would have mitochondrial DNA from the ova of another species. More importantly, the factors that led to the extinction of these species (loss of habitat, competition from invasive species, harmful human activity) have not been rectified. Any "resurrected" species would probably be limited to a few "hothouse flowers" (and not the good kind) languishing in zoos or the private reserves of the wealthy (I could well imagine Dick Cheney paying some serious cash just so he could shoot a wooly mammoth). As Alison, and many others, have noted, efforts at de-extinction would consume resources better spent on conservation, on preventing the extinction of species that we are in danger of losing.
As nice as it would be to have some of the "charismatic fauna", mega or otherwise, be brought back from oblivion, you don't just get to call a mulligan on extinction. Atrocities and screw-ups happened, we have to own up to that fact and decide to become better stewards of the planet. Our own survival may very well hinge on it.