I've been a huge fan of Jack Horner since I was in university. Horner is the American paleontologist who was among the first to recognize the link between dinosaurs and birds.
Early in his career, he says he was very fortunate to make some remarkable discoveries. He found a massive dinosaur nesting ground with clutches of eggs and nests containing skeletons of babies and numerous juveniles and adults. It led to the understanding that dinosaurs were social animals that cared for their young and traveled in giant herds. Also, the fact that babies and juveniles looked different than their parents was revolutionary.
This was a very different picture than the traditional view of dinosaurs as giant, brainless, lumbering reptiles as none of these characteristics are those of current reptiles.
Michael Crichton depicted all of this in his book Jurassic Park. He even modeled the main character, the paleontologist Alan Grant, after Horner.
If Horner inspired Crichton, and later Steven Spielberg, they inspired the paleontologist right back. Horner says he was intrigued by the idea of extracting dinosaur DNA and the premise of bringing dinosaurs back to life.
"When I was a young boy, I dreamed of two things: one, to become a paleontologist, and another, to have a pet dinosaur," he wrote in an opinion piece for CNN.
Scientists had, in fact, tried to extract DNA from insects in amber as depicted in the book, but found none, dinosaur or otherwise.
In 1993, the same year the movie Jurassic Park was released, Horner and his graduate student Mary Schweitzer received National Science Foundation grant to attempt to extract dinosaur DNA from a Tyrannosaurus rex skeleton. They didn't find any, but Schweitzer went on to find soft tissues in another T-rex specimen. No DNA.
Thinking that maybe the DNA was there, but just degrades so quickly when the fossils are unearthed, the researchers brought the lab to the field with them to try and extract the DNA immediately. No luck there either.
So, Horner thought, if they couldn't find dinosaur DNA in fossils, maybe he could retro-engineer his pet dinosaur.
I love the way this guy's mind works.
Embryology has long taught us that latent characteristics of ancestral species exist in the developmental stages of animals. Hans Larsson, a researcher at McGill University in Montreal, who was studying the transition between extinct dinosaurs and birds using developmental biology techniques. In 2009, Larsson announced he believed he could create a dinosaur by manipulating chicken embryos. Horner was inspired and the "Build a Dinosaur Project" was born.
During gestation chickens exhibit two characteristics of their dinosaur forebears, the three-fingered hand and the long primitive tail.
At some point modern chicken genes kick in fusing the fingers into a wing and resorbing the tail into the spine.
Scientists are now working on finding and repressing the genes that cause this to happen.
Of course, the main question is, why build a chickenosaurus in the first place?
As I wrote last week in this column about de-extinction, "because we can" or "because it would be so cool" just aren't good enough.
Horner sees it two ways, first, as a medium for public education. The chicken-dinosaur is a sensational story that lends itself to explaining developmental and evolutionary biology to a wide-ranging audience.
Second, he believes the chicken-dinosaur is an icon of genetic engineering, which lends itself to providing a focus for discussions about ethics.
He points out, for example, that many people bristle about the ethics of engineering a dino-chicken, but find it perfectly acceptable to selectively breed animals to achieve similar results.
Horner's latest estimates are that the chicken-dino is still at least three to five years and probably more like five to ten years away. That's a lot of time for ethical discussions.
In the meantime, I remain a huge fan.
