Revive & Restore, the de-extinction project of the Long Now Foundation, has proposed the passenger pigeon (Ectopistes migratorius) as the initial animal to be brought back from the evolutionary beyond.
Some might think that the recent discovery of a fossilised woolly mammoth (Mammuthus primigenius) in Siberia could be an alternate choice. After all, its blood is still liquid after an possible 10,000 – 15,000 years spent in the permafrost, permanently frozen soil.
There is speculation that woolly mammoth blood might have cryoprotective features that helped the animal survive long winters by protecting cells or tissues from freezing. The blood samples have remained liquid at temperatures as low as -17 °C (1.4 °F).
Most animal blood, including that of humans, freezes at around -0.5 to -3 °C (31.1 – 26.6 °F). There are fish species in the Arctic that have been studied for the proteins that prevent their blood from freezing down to temperatures of -6 °C (23.1 °F).*
Woolly mammoths, then, would have exceeded these lower limits by a wide margin.
It’s one thing to find a fossil of unexpected extinct life (the giant Arctic camel, for example), it’s quite another to find blood and tissue of a long-extinct animal. Other samples of woolly mammoth tissue have been found before – this latest is the most intact thus far.
Still, this discovery means that cloning a mammoth is only a slightly less remote impossibility than before because of the likely degradation of the blood cells and DNA.
Another revelation with receding glaciers and permafrost: the revival of plant ecosystems that were dormant under centuries of ice. I’ll write about this tomorrow.
*According a Wired.com article: “The research was funded by Volkswagen, who no doubt want to find better ways of anti-freezing their cars. The natural proteins found in the fish perform far better than man-made antifreezes, which bond directly with water molecules to lower the freezing point. The proteins don’t need to bond. Their mere presence is enough to slow freezing.”
LiveScience article – Despite Mammoth Blood Discovery, Cloning Still Unlikely by Tia Ghose