Scientists Have Devised a Dino-Chicken. Now What?
The intense longing on the part of <i>Jurassic Park</i> fans and other nerds to see some vestige of extinct dinosaurs revived is looming over the latest research.
On Tuesday, the scholarly journal Evolution nonchalantly published an article detailing a successful attempt by American researchers to manipulate chicken embryos so as to restore dinosaur-like snouts, a predecessor to the modern beak. The researchers were able to identify two proteins that seem to have evolved to fuse snout bones together. Blocking the proteins essentially amounts to rewinding the evolutionary clock by tens of millions of years.
This act of selective time-traveling through modern birds to their dinosaur ancestry, especially so close to the release of Jurassic World, may inspire hope that researchers will soon be able to create quasi-dinosaurs from living creatures. Scientists say that isn't totally impossible, although it's highly unlikely—and the paper's authors cannot stress enough that this is not their aim.
"Please understand that this is not why we did these experiments," Harvard biologist and paper co-author Arkhat Abzhanov told VICE. "We were driven to explain how modern birds, with their unusually shaped crania, evolved from a more reptilian condition. It is exciting to know that one can actually explain a specific part of such vast evolutionary transformations in mechanistic terms, and it will take an enormous amount of research to understand the full complexity of the dino-to-bird transition."
Despite Abzhanov's words of caution, the intense longing on the part of Jurassic Park fans and other nerds to see some vestige of extinct dinosaurs revived is sure to hover over their research. After all, the 1993 blockbuster and its simplistic concept of using preserved dinosaur blood as a source of DNA to be inserted into modern reptiles' eggs has almost certainly helped popularize efforts to bring back ancient species through similar methods, most notably in the de-extinction movement.
As of 2014, scientists in Russia and South Korea had initiated a project to birth a Woolly Mammoth by implanting an intact nucleus from a frozen specimen into a live Asian elephant embryo. Meanwhile, other researchers aim to create hybrids by splicing mammoth and elephant DNA. Both processes sound a lot like those described in Jurassic Park by author Michael Crichton. While the mammoth efforts are unlikely to succeed, it's conceivable that we might revive more recently deceased creatures like passenger pigeons within the next couple of decades (which conservationists fear could make extinction seem less dire than it does now). The technology could well improve from there, allowing the recovery of older and older species, feeding fantasies of a real Pleistocene Park full of Woolly Mammoth-era life carved out of rural northern Siberian territory.
However, de-extinctionists rarely discuss reviving dinosaurs, if only because they can't be revived through traditional cloning or splicing practices. All DNA degrades over time, and the longest a strain could even conceivably survive is 6.8 million years, about one-tenth of the time that dinosaurs have been extinct. For lack of genetic blueprints and of closely related species into which to place their DNA, recreating dinosaurs or even dinosaur-like hybrids has long been far out of human reach. Dino enthusiasts have had to suffice with a few real and proposed animatronic dinosaur parks instead.
Still, even before the Evolution publication, some scientists believed that it might be possible to approximate dinosaurs, only not recovering their genetic information, but rather by functionally reversing their evolution. The idea is to lean on what we know of the fossil record and the development of uniquely avian features in modern birds. Last year, Jack Horner, a notorious paleontologist at Montana State University, proposed a similar process to the one used in the beak-to-snout experiments to help restore reptilian tails in modern bird species. Such processes wouldn't be able to restore an actual dinosaur, but it could work us back towards something like the tiny, proto-bird archaeopteryx.
"[The evolution of birds from dinosaurs] implies that buried deep within the DNA of today's birds are switched-off genes that control dinosaur-like traits," University of Oxford biochemist Alison Woollard told the Telegraph in 2013. "In theory we could use our knowledge of the genetic relationship of birds to dinosaurs to 'design' the genome of a dinosaur."
For his part, Abzhanov believes that we may be able to revert features besides the beak.
"For example, a closer comparative analysis may reveal a mechanism which allows for birds to be warm-blooded as opposed to the crocodilians, which cannot control their body temperature," he told VICE. "Removing such a mechanism from a modern bird then may revert it to the more primitive cold-blooded condition."
However, Abzhanov and others point out that even if we can revert other parts of bird embryos, we don't have a roadmap to revive all of the dinosaur-era traits within them. We have a good understanding of the evolution of birds from dinosaurs, but it's not definitive, and we certainly don't know enough about bird genomes to understand which parts of them are ancient candidates for editing, especially given our complete and eternal lack of a dinosaur comparison.
"[Our] work is a first step," Yale paleontologist and paper co-author Bhart-Anjan Bhullar told VICE, "but it will be some time before we even know what parts of the genome could be altered into more ancestral sequences to ultimately produce more ancestral phenotypes."
Abzhanov also points out that making a change in an embryo doesn't mean that a creature can live with that specific alteration to its otherwise modern physiology. And as some aspects of their older bodies might be lost forever, that could mean that a living hybrid is effectively beyond reach.
"It is unlikely that [our unborn embryos] would survive very long," he says. "The slender palate bones of modern birds are shaped to allow for the movement of the upper beak—something they require for normal eating. This function would be strongly affected, if not impossibly, in many of the experimental chickens [i.e. they might well be unable to eat].
"At this point we do not know yet if [a dinosaur hybrid] is really possible. Many of the dino features have not been used by birds for tens of millions of years, so they may be gone forever genetically."
Still, even if they can never bring back an actual dinosaur or a quasi-dinosaur hybrid, Abzhanov, Bhullar, and their team have brought mankind about as close to living dinosaurs as we've been in millions of years. That's enough to drive the dreams of dino lovers for a few decades more, potentially launching some good new sci-fi franchises, if not actual, living specimens.
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