United States-based Colossal Biosciences says it has made a major breakthrough for its projects including the proposed South Island Giant Moa de-extinction programme.
Scientists are split over claims from United States-based Colossal Biosciences, which says it has successfully hatched chicks using a fully artificial egg system designed to support the development of avian embryos outside a natural shell.
While the company describes the breakthrough as a step towards scalable de-extinction and conservation technologies, independent scientists range from cautious optimism about the engineering to outright rejection of the de-extinction framing.
Colossal says the shell-less incubation platform can carry embryos from early development through to hatching without a biological eggshell or supplemental oxygen, positioning it as a foundational tool for projects such as the proposed South Island giant moa de-extinction programme.
“Restoring species like the South Island giant moa isn’t just about reconstructing ancient genomes and editing PGCs [primordial germ cells] - it requires building an entirely new incubation system where no surrogate exists and scales in ways that ordinary biology simply doesn’t,” said Colossal Biosciences CEO Ben Lamm.
“At Colossal, we didn’t just replicate the egg; we re-engineered it from first principles to create something more scalable and controllable.”
The company said earlier shell-less systems required high oxygen environments that limited scalability and raised concerns about embryo health.
The approach uses a bioengineered silicone-based membrane lattice designed to replicate natural gas exchange under normal atmospheric conditions.
Co-founder of Colossal and professor of genetics at Harvard Medical School, Dr George Church, said: “The embryo needs a place to grow that recapitulates the gas exchange, humidity and mechanical environment of a natural egg — at whatever size the species requires.
“Colossal’s artificial egg solves the scalability dimension. It is a platform technology.”
Chief science officer Dr Beth Shapiro said that for species where surrogacy was impossible and genome recovery has outpaced an ability to use it, the latest development was “the missing piece”.
Colossal said there were numerous other potential applications beyond de-extinction, including conservation breeding and genome-edited avian biotechnology.
However, scientists contacted by the Science Media Centre offered sharply contrasting assessments.
Director of Genomics Aotearoa at the University of Otago, Professor Peter Dearden said: “So before we get to the egg itself, let’s be clear that this is, in my opinion, impossible”.
“The lineage that led to moa descends over 4.3 billion years to the last common ancestor of all life on earth. That lineage is extinct. No amount of fancy molecular biology can bring it back as it was. So, if anything can be brought back, it will be a poor replica of what a moa might have looked, sounded and acted like - a man-made, and human-dependent ghost.”
“Shell-less culturing of chickens has been going on in research labs for some years, so this is not novel. What is novel is a shell that the company believes they will be able to expand to make bigger eggs.”
Professor Amanda Black of Bioprotection Aotearoa said: “Clearly Colossal Bioscience is making strides in technological breakthroughs, which is always fascinating to read, it’s just unfortunate that it seems to want to continue cosplaying conservationists”.
“Biology is vastly more complex than what engineering can currently offer and the suggestion we can simply engineer our way out of conservation problems of our own making is an eggsaggeration,” she said.
Associate Professor Nic Rawlence of the University of Otago said: “Credit where credit is due, this is really impressive work that could result in a new tool in the conservation toolbox in the future”.
“However, it must be noted that there is no data or peer-reviewed publication associated with this announcement, just a press release and glossy video.”
“Extinction is still forever and to imply otherwise risks losing protection for threatened species and could provide an excuse for governments and industries for more environmental exploitation.”
Associate Professor Michael Knapp said the science was impressive, and may in time provide conservation benefits, including for highly threatened New Zealand bird species such as the kākāpō and the kakī.”
Professor Emeritus Philip Seddon agreed it was an “amazing technical feat -but it does seem to be a solution in search of a problem”.
“Genetic modification of a near relative of the moa could create an ecological proxy, but could not resurrect a moa.”
Despite criticism, several scientists acknowledged potential value in the platform.
“This technology is a valuable tool that, when combined with genome engineering techniques still in development, may be able to reverse the impacts of inbreeding on low hatching success for example,” said Rawlence.
Knapp also said the work could help unlock conservation applications that were previously inaccessible.
Colossal said the platform is still in development, with future iterations expected to include larger-scale eggs, self-hatching systems and robotic embryo transfer to reduce variability.
Ben Tomsett is a multimedia journalist based in Dunedin. He joined the Herald in 2023.