The egg that isn't an egg (but might work anyway).
Colossal is at it again. This is a company that is famously known to try & bring back extinct species, none of which have been successful—not a mammoth, not a thylacine, not a dodo, not a moa, not anything. Not even close. I've been following this topic for quite a while now, & all I've been seeing are press releases, fundraising efforts, cell-line editing experiments, computational genome reconstructions, & theoretical models for surrogate species. They seem to have taken a step forward recently, if the claims can be verified. They claim to have successfully hatched chicks using 3D-printed artificial eggs with a silicone-based gas exchange membrane, allowing the chicks to breathe air through the membrane without the need for supplemental oxygen. If true, this would be an improvement because former artificial eggs needed supplemental oxygen for the developing chicks to breathe. The former artificial eggs often failed because embryos suffocate without a natural shell's microporosity. This membrane allows oxygen diffusion, CO₂ release & humidity regulation.
The claim is clearly an overstatement that they "created the first shell-less incubation system." The technology (if proven accurate) is essentially a modification of existing methods. So far, the results have not appeared in a peer-reviewed scientific paper. It sounds impressive, but then it would, because it's a press release. It is not a "fully artificial egg." More precisely, a more apt description might be an artificial eggshell. Basically, they transferred the contents of freshly laid chicken eggs into the artificial shells, then incubated them until some chicks hatched. Colossal eggs require extra calcium because a real shell supplies some of this essential mineral during development. Colossal would like to use this method to revive the extinct giant moa, a flightless bird from New Zealand that could stand more than 12 ft tall (3.6 m) & weigh 510 lb (230 kg). They became extinct after Polynesian settlers arrived in New Zealand. The birds had no evolutionary warning signs about the danger humans brought with them. They were hunted relentlessly; they were basically sitting ducks.
But making a moa-like bird would require far more than a large artificial egg. This is a fundamental flaw that assumes the egg came first. Biologically, the egg is the last step, not the first. You cannot start with the container when you have no embryo, no yolk, no genome, no surrogate, & no developmental pathway. Scientists would first need to reconstruct ancient moa DNA from the bones they have. Then they need to edit 1,000s of genetic differences into the genome of a living relative, the emu, for example. Even then, it would be an engineered proxy/hybrid (a living bird designed to resemble an extinct one). Size is yet another problem. An egg yolk is a single cell, & it can't be enlarged like a balloon without collapsing developmental biology. You cannot print a yolk.
The strongest case for their technology may be to help rescue embryos from damaged eggs & support breeding programs for rare birds, for endangered bird conservation & controlled generation of genome-edited avian lines, rather than de-extinction itself.
