Zombie Mammoths: The Science of De-Extinction
In the early 1800s, the North American sky was periodically eclipsed for up to three days by vast, black clouds of passenger pigeons, the most abundant bird on the planet. Flocks numbered in the billions, and left enormous swathes of destruction in their wake, their excrement carpeting the ground in layers 3 feet thick. In 1900, just a century later, the last known wild specimen was killed. The culprit was a 7 year old boy trying out his BB gun for the first time.
Recently, a new organization called Revive and Restore has proven that extinction may not be the end of the road for numerous animals, but just a temporary faltering.
De-extinction has often been toted as the epitome of scientific achievement, but it has only become a realistic possibility until recently. Previously, animal restoration was hindered by difficulties in preserving DNA; DNA is easily contaminated by other organisms, and is susceptible to deteriorating from enzymes, oxygen, and ultraviolet radiation, thus posing a problem for scientists relying on long-term preservation.
However, a newly developed technique denoted new-generation sequencing allows computers to decode flawed and fragmented DNA to formulate a larger image of an animal’s DNA structure. Though the passenger pigeon provided the ideal subject for de-extinction due to the abundance of specimens and DNA contained in museums, Revive and Restore had difficulty in obtaining large samples of DNA and had to make do with fragmented samples that were difficult even for the new-generation sequencing to use.
As a result, scientists used the DNA of the passenger pigeon’s closest living relative– the modern band-tailed pigeon– as a scaffold for the DNA structure of the passenger pigeon. The next step is to edit the DNA using Multiplex Automated Genome Engineering from a band-tailed pigeon germ cell – the cell type that develops into sperm or eggs – to match that of the passenger pigeon. Next– implanting the germ cell into the egg of another pigeon, such as a modern rock pigeon, and hoping that the germ cell will migrate to the gonads of the developing chick. By breeding two adult birds resulting from such a procedure, a scientist could produce an extremely realistic, though slightly flawed, representation of the passenger pigeon. If creating passenger pigeons is a successful process, Revive and Restore hopes to retrain the birds of the ancestral migration patterns by allowing them to observe the flying patterns of homing pigeons.
However, though Revive and Restore believes that reintroducing the passenger pigeon will lead to a more stable ecosystem and healthier, fertilized soil, many scientists are skeptical of reintroducing the passenger pigeon; they are fearful of environmental distress resulting from their large numbers and rapid propogation. De-extinction is not only confined to the passenger pigeon; projects are underway with restoring the Wooly Mammoth that once was a frequent patron of North American grasslands during the Pleistocene era. Suggestions of bringing back humanoids such as Neanderthals have beens stalled due to ethical reasons, but scientists are aware of the possibility. Who knows? Perhaps in the future you’ll glance out the window to a bevy of wooly mammoths sauntering down the streets of Oakland.