The recipe for making any creature is written in its DNA. So last November, when geneticists published the near-complete DNA sequence of the long-extinct woolly mammoth, there was much speculation about whether we could bring this behemoth back to life.
Creating a living, breathing creature from a genome sequence that exists only in a computer's memory is not possible right now. But someone someday is sure to try it, predicts Stephan Schuster, a molecular biologist at Pennsylvania State University, University Park, and a driving force behind the mammoth genome project.
So besides the mammoth, what other extinct beasts might we coax back to life? Well, it is only going to be possible with creatures for which we can retrieve a complete genome sequence. Without one, there is no chance.
The genomes of several extinct species besides the mammoth are already being sequenced, but turning these into living creatures will not be easy (see "Revival recipe"). "It's hard to say that something will never ever be possible," says Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, "but it would require technologies so far removed from what we currently have that I cannot imagine how it would be done."
(Links in the paragraphs quoted above are those provided in the original article.)
The ten* creatures which the article suggests as possibilities for resurrection are:
Sabre-toothed tiger (Smilodon fatalis)
Neanderthal (Homo neanderthalensis)
Short-faced bear (Arctodus simus)
Tasmanian tiger** (Thylacinus cynocephalus)
Glyptodon (Doedicurus clavicaudatus)
Woolly rhinoceros (Coelodonta antiquitatis)
Dodo (Raphus cucullatus)
Giant ground sloth (Megatherium americanum)
Moa (Dinornis robustus)
Irish elk (Megaloceros giganteus)
Giant beaver (Castoroides ohioensis)
The woolly rhinoceros and the thylacine are listed as having the best chance of suitable DNA preservation, while the Neanderthal and the woolly rhino have the best chance of finding a surrogate mother to bear the first generation.
The gorilla (Gorilla gorilla) is also listed as a possibility - they're not extinct yet, but they're getting there. There are already samples of their DNA being preserved, and chimpanzees would make good surrogates.
Personally, I'd most like to see the mammoths, rhinos, sabre-tooths, short-faced bears and sloths brought back. As for animals not included in this list, I'd really, really like to see a living Titanotylopus nebraskensis.
* According to the article, but eleven by my count.
** Also known as the thylacine and the Tasmanian wolf.