Making Jurassic Park a Reality

June 16, 2015

5-minute read

Making dinosaurs from recovered DNA as seen in Jurassic Park was thought to be unrealistic. But is the idea really so far-fetched? Ask Science explores two new studies that suggest bringing dinosaurs back to life may be more plausible than we thought.

151 EE Making Jurassic Park a Reality

Your browser doesn’t support HTML5 audio

Hi, I’m Sabrina Stierwalt, and I’m Ask Science bringing you Quick and Dirty Tips to help you make sense of science.

Dinosaurs are fascinating. These ancient animals, which no human has ever laid eyes on, are very different from most of the animals we know today. Yet they provide an important link to the history of our planet. Understanding the cause of their mass extinction may also give us a glimpse of our own fate.

Our enthusiasm for dinosaurs starts young—my one-year-old daughter’s favorite pajamas are the ones covered in Tyrannosaurus rexes. And based on the $500 million brought in by the debut of the Jurassic World movie last weekend, we adults still maintain a healthy amount of dino-related curiosity of our own. However, we can only learn about these monstrous creatures through clues left behind in their fossil record or through birds, their modern day ancestors.

In a previous episode, we discussed the science behind making dinosaurs in the original Jurassic Park movie. In their Hollywood-scripted lab, those scientists were able to extract dinosaur DNA from the bellies of mosquitoes that had been preserved in amber for more than 60 million years. While mosquitoes are indeed found trapped in amber and the pesky insects were known to exist at the same time as the dinosaurs, the likelihood that DNA could survive past even 10 million years seemed dubious.

The protein molecules that make up the soft tissues, like skin and blood vessels, decay very quickly and are often eaten by microbes in a matter of weeks. Thus, they aren’t expected to last for longer than 1 to 4 million years. Fossils are instead composed of the inorganic components of bones like mineral salts. In fact, scientists have been so sure that any type of organics could not be preserved in fossilized remains for such long time periods that they don’t even look for them.

But is the idea really so far-fetched?

Preserving Dinosaur Tissue

In 2005, Mary Schweitzer, a molecular paleontologist at North Carolina State University, and her team, made a discovery that scientists thought was impossible. They claimed to have found soft tissue—transparent, flexible tissue that was not fully decomposed—preserved in a 68-million year old bone from an adolescent Tyrannosaurus rex dug up in Montana.

The discovery of such tissue was so unheard of that the result was immediately controversial. Many thought it must certainly be the result of some type of modern contamination.

Through continued research, however, Schweitzer and her team ruled out possible contaminants and determined their sample to be a type of dinosaur collagen or connective tissue. More importantly, they’ve determined how such a sample could remain in tact for so many tens of millions of years: iron.

Iron molecules are highly reactive and can act as catalysts for the creation of free radicals, or atoms with uneven numbers of electrons. These free radicals are even more chemically reactive and can cause damage to cells as well as contribute to aging. Luckily, the iron in our bodies is kept confined in bonds with other molecules so that it behaves while we are alive.

After death, however, that iron is set free to roam. The free radicals it aids in producing can mimic formaldehyde, which works as a preserver of tissue. Formaldehyde preserves tissue by cross-linking the amino acids within certain proteins with nitrogen atoms found in similar proteins or in DNA. The result is a sort of caged or protected protein that is more resistant to decay.

So, scientists had to admit that it was possible: soft tissue from dinosaurs could be preserved for tens of millions of years!

So, scientists had to admit that it was possible: soft tissue from dinosaurs could be preserved for tens of millions of years! However, the more time passes once a fossil is unearthed, the less likely it is for organic molecules to remain. Also, the collagen tissue found by Schweitzer’s team came from exceptionally well-preserved samples and thus was considered by many to be rare event.

Ten years later, however, that idea is changing thanks to new results published last week from Sergio Bertazzo, a materials scientist, and Susannah Maidment, a paleontologist, from Imperial College in London. They found collagen strands and what they believe could be red blood cells in a 75 million year old dinosaur claw that had been just sitting in the Natural History Museum for over a century. Incredibly, the sample containing the tissue had not been carefully preserved at all.

These new results have tremendous potential for the number of samples that could contain dinosaur tissue. Hypothetically, such samples could also contain viable “dino-DNA” although that has yet to be proven. But perhaps there is a more direct way to get dinosaurs without having to pick through bones in search of relic DNA?

Bringing Back Dinosaurs Through Birds

That is exactly what paleontologist Jack Horner of Montana State University thinks. Horner, who has been a scientific consultant on the Jurassic movies, has written books and given TED talks about his research to alter avian genetics to recreate the dinosaurs of the past. Since scientists now agree that birds are likely the descendents of a few dinosaur species that survived the mass extinction, rather than working forward from dinosaur DNA, we can instead work backwards starting with a chicken, for example.

This form of what he calls “transgenic engineering” can in theory block certain more recently evolved genes and turn on dormant ones left behind by their dinosaur ancestors. Last month, this theory became a reality.

Bhart-Anjan S. Bhullar, a paleontologist and developmental biologist from the University of Chicago and Yale University, and Arhat Abzhanov, a developmental biologist from Harvard, were able to flip a genetic switch to change the facial structure in chicken embryos.

Birds have two genes that dictate the progress of their facial development: one that favors the beaks we know them to have today and another that produces more snout-like noses akin to those of the dinosaurs of the past. The biologists were able to block the proteins associated with the gene linked to beaks, thus causing the snout proteins to do their work instead. The result was a chicken embryo with the face of a velociraptor.

So, are we about to see pet dinosaurs being walked on leashes alongside dogs? While scientists like Horner would hope so, Bhullar is more interested in understanding the molecular pathways that lead to different evolutionary adaptations. The embryos in his study were each “humanely euthanized” before it could become a full grown chickenosaurus.

Although creating dino-chickens that walk among us may seem like only a movie plot, we create genetically modified animals all the time, just usually over longer timescales. I need to look no further than my French bulldog to see proof of that. The only evolutionary advantage provided by her stubby legs, loud snoring, and ridiculously perky ears is that I find her helplessness irresistible and am driven to care for her.

So, whether we start from the beginning with dinosaur DNA found preserved in fossils, or start from birds and work our way back, walking among the dinosaurs is still a far off concept, but not a scientific impossibility. Perhaps it couldn’t hurt to check out one of these movies to see what we might be in for!

Until next time, this is Sabrina Stierwalt with Ask Science’s Quick and Dirty Tips for helping you make sense of science. You can become a fan of Ask Science on Facebook or follow me on Twitter, where I’m @QDTeinstein. If you have a question that you’d like to see on a future episode, send me an email at everydayeinstein@quickanddirtytips.comcreate new email.

T-rex image courtesy of Shutterstock.