The phrase “dead as a dodo” may be, well, dead as a dodo, if a recently-founded “de-extinction company” has its way.
Colossal Biosciences, founded in 2021 by entrepreneur Ben Lamm and Harvard geneticist George Church, announced on Tuesday that it plans to resurrect and rewild the dodo, the iconic flightless bird that has become a powerful symbol of extinction after it was rapidly wiped out as a result of human interference on its native island of Mauritius.
Colossal is already working on efforts to de-extinct the wooly mammoth and thylacine (aka the Tasmanian tiger), and reintroduce them to wild habitats. In the process, the company hopes to pioneer new technologies with applications in conservation biology and human healthcare, to name a few.
Now, the company has added the dodo to its de-extinction wishlist and tapped Beth Shapiro, an evolutionary biologist at the University of Santa Cruz, to back the project. The team envisions the return of a “proxy” version of this idiosyncratic bird, meaning a species with edited DNA as opposed to an exact clone, to its original habitat in Mauritius.
“I've always been fascinated with the dodo,” said Shapiro, who led the team that fully sequenced the dodo’s genome for the first time, in a call with Motherboard. “It’s the poster child, in a sad way, for how human habitat alteration can drive species to extinction.”
“I think this is an opportunity where, given the man-made nature of the extinction of the dodo, man could not only bring the dodo back, but also fix what was done to parts of the ecosystem to reintroduce them,” noted Lamm in the same call. “There's a lot of benefits from a conservation perspective, in terms of what we can learn from rewilding.”
It’s tantalizing to imagine the dodo emerging from the haze of myth and memory and returning, in the flesh, to the forests of the island nation that nurtured its unique characteristics for millions of years.
The flightless bird was such a one-off that its closest living relative is the Nicobar pigeon, a colorful flying bird that looks completely different from its famous extinct cousin. The bizarre appearance distinguished the dodo as a cultural curiosity practically from the moment European explorers came across it during the 17th century.
But some of the very characteristics that set the bird apart from all other animals also made it particularly vulnerable to extinction. Before the arrival of Europeans, and the invasive animals they brought with them, there were no mammals on Mauritius that hunted the birds. With no real experience of predators, the dodo was docile and easily killed by humans and other introduced species. This heavy predation, along with the rapid destruction of its forest habitat by humans, drove the dodo to extinction before the turn of the 18th century.
Now, Shapiro and her colleagues are tackling the challenge of stitching together a dodo-like animal using genomes that have been sequenced from real dodo specimens, as well as genomes from their close relatives, such as the Nicobar pigeon and the Rodrigues solitaire, another extinct flightless bird that lived on the nearly island of Rodrigues. Indeed, de-extincting the dodo will have to start with reverse-engineering it.
“Once a species is extinct, it's really not possible to bring back an identical copy,” Shapiro said. “The hope is that we can use, first, comparative genomics so we can get at least one, and hopefully more, dodo genomes that we can use to look and see how dodos are similar to each other, and different from things like the solitaire.”
From there, the team will “compare those to the Nicobar pigeon, and other pigeons, and identify mutations in that genome that we believe may have some phenotypic impact that made the dodo look like a dodo instead of like a Nicobar pigeon,” she continued.
Getting the right genetic ingredients for a dodo proxy is only the first hurdle in what may be a long scientific quest. The researchers will also have to figure out how to get a dodo embryo into an egg so that a new generation of birds can successfully hatch.
Given that most cloning and gene-editing technologies focus on mammals, Shapiro and her colleagues acknowledge that they will need to be creative in their approach. For this reason, Colossal has launched a broader collaboration called the Avian Genomics Group that could have wide-reaching consequences for bird conservation, regardless of whether the company actually achieves their vision of resurrecting the dodo.
“These are the technologies that are required for any sort of gene-editing in birds,” Shapiro noted. “We know that we can grow these cells in some species so we know we can get there. Now, we have to do all the experimentation.”
“I'm really excited about advancing these technologies,” Lamm said. “Any technology that we develop that has applications to conservation, we want to subsidize and just give to the world.”
As with many emerging fields, the science of de-extinction contains many ethical nuances in addition to its technical challenges. Tom Gilbert, who serves as director of the University of Copenhagen's Center for Evolutionary Hologenomics, told Motherboard that proxies for extinct species may well be technically feasible, but that is only the beginning of the conversation.
“The question really is, how close will the proxy be to the extinct form?” said Gilbert, who recently joined Colossal’s advisory board, in an email. “That’s a much harder question, and not straightforward to answer, given it raises the question…what are you measuring? Genomic similarity? Physical similarity? Similarity in the niche it fills/what it does, even if it doesn’t look the same (e.g. if you can make an elephant able to live in the cold where it acts like a mammoth…is that enough??
“For reasons I’ve argued before in various articles I think that the best we can hope for is something that is an equivalent with regard to the niche it fills,” he continued. “This raises the question of is it worth it? Here it's also not black and white. Sometimes maybe, but in other cases maybe the environment is so changed already that the hope of free living populations is far from what can be done. One has to bear in mind e.g. how much, relatively, human untouched environment is left.”
That said, Gilbert said he would absolutely travel to see a recreated mammoth, and he noted that these charismatic proxy species could be an effective way to raise awareness of the plight of living species that are currently at risk of extinction. Lamm and Shapiro also spoke to the potential for resurrected proxies to galvanize efforts to preserve and restore ecosystems that are at risk of, well, going the way of the dodo.
“My approach to the dodo was always deeply about the plight of the species that are in danger of becoming extinct now,” Shapiro said. “Because everyone thinks of extinction and the dodo together, it really provides an opportunity to make people care a little bit more about what's going on. That is one of the many reasons why I'm so excited about this particular project.”