Native only to the island of Mauritius in the Indian Ocean, dodos were extinct by 1681. European ships arriving in the 16th century brought a range of predators with them, but they were also hunted and slaughtered wholesale.
The phrase “dead as a dodo” means gone forever — but now scientists at a company called Colossal Biosciences want to bring the flightless but fearless birds back, along with the woolly mammoth and the Tasmanian tiger. But the technical challenges remain immense.
Living cells degrade after death, but DNA takes a much longer time to disintegrate. Extinct genomes have to be pieced back together based on what’s left in preserved remains. But when scientists try to put together this puzzle, there will always some blanks they can never fill.
When is a mammoth not a mammoth?
In its quest to “de-extinct” the woolly mammoth, Colossal Biosciences is starting instead with fully intact DNA from the extinct species’ closest living relatives. The genome from the Asian elephant is over 99% identical to the mammoth genome, so the scientists are editing the DNA in an elephant cell, adding individual mammoth genes. They hope the resulting embryos will then develop into baby elephants that also have mammoth trait like smaller ears, or a woolly coat. But is that really a mammoth?
And there’s another issue. Even if the scientists succeed, where will the facsimile species go? The ecosystem on Mauritius, for instance has changed dramatically in the centuries since the dodo died out. Could functional versions of them be released into the wild there? Or would they have to remain protected in zoos? But perhaps the biggest question remains: assuming we could do it — should we?