The writer is a science commentator
Portuguese sailors first spied the creature in Mauritius in the early 16th century and reportedly named it “doudo”, meaning fool. The trusting, tubby, flightless bird became a sitting duck for hunters and easy prey for introduced species such as cats and dogs.
The last dodo is thought to have been hunted in the 1660s. Now, scientists want to bring it back. Colossal Biosciences, a US genetics start-up that describes itself as a “de-extinction company” and which is already targeting the woolly mammoth and Tasmanian tiger, said on Tuesday it would try to revive the defunct species through genome editing.
Ben Lamm, who co-founded Colossal with Harvard University genetics professor George Church, said it aimed to reverse human-inflicted biodiversity loss and was “excited to work to bring additional species back to the planet”. The company says its focus is on developing conservation technology, to be given away freely, and human healthcare.
The recovered species will not be a facsimile of the original but more of a lookalike. According to one of the company’s own advisers, creating a real dodo is currently impossible.
Colossal’s proposed bestiary of “proxy species” raises other issues too. These include the practical challenges of bringing altered embryos to term; the ethics of releasing resurrected species into habitats that have since changed; whether the revived animals will fulfil the ecological function for which they were crafted; and whether conservation is better served by protecting existing endangered species.
Still, investors are piling in. Tuesday’s announcement revealed an oversubscribed $150mn funding round, bringing total investment to $225mn since Colossal’s inception in 2021. Backers include bitcoin entrepreneurs Cameron and Tyler Winklevoss, and Thomas Tull, former chief executive of Legendary Entertainment.
The strategy for reviving the dodo is to first sequence its genome, using bone specimens and other fragments, and then gene-edit the cell of a close relative, the Nicobar pigeon, so that its genome resembles that of a dodo. That genetically altered cell will then be used to create an embryo. The resulting chick will be something between the Nicobar pigeon and the dodo.
The Nicobar looks like a pigeon; the dodo more like a turkey. Tom Gilbert, a professor of paleogenomics at the University of Copenhagen and recently appointed to Colossal’s science advisory board, has previously questioned how representative any resurrected species would be. “It is not possible to bring back a true dodo, as defined as genetically identical to the extinct form,” Gilbert tells me. But despite his reservations about de-extinction, he says a lookalike might send a powerful message: “If a dodo-like animal stops people trashing what we have left . . . or stops them buying illegally trafficked animals . . . I’m 100 per cent behind the idea.”
Unlike cloning, which requires a cell from a living animal, remaking a lost species involves gleaning genetic clues from ancient DNA fragments and filling in the gaps using the genome of a closely related surviving species. Last year, Gilbert’s team tried reconstructing the genome of the extinct Christmas Island rat, using two preserved skin specimens plus the Norway brown rat as the surviving reference species. They mapped 95 per cent of the extinct genome, but this was not enough to bring it back: the missing 5 per cent covered critical survival functions like immunity.
Cloned and hybrid embryos are also linked to a high rate of birth defects. The only known effort to clone a newly extinct animal, the Pyrenean ibex, took 57 embryos and resulted in one calf that died minutes after birth.
Helen Pilcher, whose 2016 book Bring Back the King explored de-extinction science, says that without a strong ecological case for reviving the dodo, she would rather resources be invested in, say, conserving the last two northern white rhinos.
Professor Beth Shapiro, Colossal’s lead paleogeneticist, admitted the role of dodos in the Mauritian ecosystem was not well-understood, but added that making a “functionally equivalent” species would drive conservation technology forward.
Colossal hopes its replica mammoths, tuskless to deter poachers, will debut in 2028. The proxy dodos and Tasmanian tigers could arrive earlier.
Blockbuster science, though, will not compensate for low-budget stewardship. The International Union for the Conservation of Nature, meanwhile, lists more than 42,000 real species threatened with extinction right now. It is not particularly reassuring to think they may one day return in proxy form.