Science advances by leaps and bounds, with experiments in the field of cloning that amaze anyone who is interested in them. But replicating what the Jurassic Park movie shows us has certain barriers that we cannot overcome . At least for now.
Michael Crichton ‘s novel Jurassic Park , which was made into a film by Steven Spielberg, sparked the dinosaur craze. In this fiction, the tycoon John Hammond spared no expense to resurrect some of the dinosaur species that became extinct 65 million years ago. The film’s researchers achieve this fantasy by extracting dinosaur DNA from blood drunk by a mosquito preserved in amber . They complete the genetic information with amphibian DNA and that’s it, dinosaur to the incubator to release it on an island as soon as it is born. This idea is, as we say, fantasy.
3 steps to resurrect a dinosaur
All in all, we have spent a couple of decades with scientists revolutionizing genetic engineering , showing cloning methods that still seem like fiction to many of us. These researchers are clear about it, you only have to overcome three steps to be able to clone a current species or resurrect a fossil species.
First of all, we need good quality genetic material . The second step would be to sequence all the genetic information in that DNA. And finally, we have three methods to clone the species : introducing the genetic material into an egg cell (as was done with the famous Dolly the sheep ); from closely related species, for example using an elephant to clone a mammoth; or creating the species entirely in the laboratory, as in the movie Jurassic Park.
With this last paragraph you may have wanted to save to buy the first ticket for sale in a zoo of extinct species. Nothing is further from reality. From theory to practice there are an infinity of barriers, possible errors and problems that ruin scientific attempts. For a Jurassic Park we cannot go directly past the first step: we do not have dinosaur DNA. We have managed to capture protein remains, such as the collagen of a Tyrannosaurus rex , which served to show that its closest living relatives are chickens and ostriches. There is research that defends that all traces of DNA disappear completely after 7 million years . After 65 million years have passed since the last dinosaur walked this world, it seems impossible to get past the first step of cloning one.
First a goat, then a mammoth, and then…
But the race to resurrect extinct species has already begun . Mammoths are among the main candidates to be rescued from the past , since they are species not so distant in time and can be found frozen, which helps preserve organic materials that contain DNA. In fact, in 2015 two complete genome sequences of the woolly mammoth, 4,300 years old and 44,800 years old, found in the Siberian permafrost, were presented . First step passed. The next is to obtain intact nuclei from mammoth eggs to implant them in the egg of an elephant breast, which would gestate inside, not an elephant, but a mammoth.
This way to bring back an extinct species has a more successful case than you imagine. In 2003, a bucardo was born from a domestic goat , a subspecies of mountain goat that was considered extinct as of the year 2000. Three years later, scientists managed to implant an ovule from which a bucardo was born. And they did. Unfortunately, the newborn bucardo died a few minutes later due to respiratory problems.
If it is difficult with a current species, from which they were able to extract DNA from a specimen still alive, you can imagine how far we are from opening a park full of dinosaurs. Looking for solutions, we have a very crazy case. Jack Horner , a paleontologist who worked as a consultant on Jurassic Park, proposes doing the cloning route in reverse. That is, from a chicken, retrieve a Tyrannosaurus rex . It consists of playing with the genes of a current species until all the lost traits of its genome are recovered. This theory of involution , incredible as it may seem, exists and is on the laboratory bench. It was from this process that they managed to make a hen, instead of a beak, have a small jaw with teeth . Fascinating and terrifying at the same time, yes.
What if we make it?
There were intentions to clone one of the precursor species of birds, but the ethics committees did not give the go-ahead to continue with the experiment. And this is another barrier that is difficult to overcome: scientific errors and problems are joined by moral and ethical arguments . Many of them are exposed in Jurassic Park, most notably through the character Ian Malcolm . An extinct species that we bring back to life could not live in freedom, for its safety, ours and that of the ecosystem. And it is that we could start with what seems like a scientific achievement, and end with a Tyrannosaurus rex loose in San Diego.
Meanwhile, scientists continue to discover more about the ancestral genome of birds and the different options by which extinct species can be rescued. We will keep an eye on the news.
References:
Folch, J. et al. 2009. First birth of an animal from an extinct subspecies (Capra pyrenaica pyrenaica) by cloning. Theriogenology 71, 6, 1026-1034 . DOI: 10.1016/j.theriogenology.2008.11.005.
Horner, JR et al. 2009. How to build a Dinosaur: extinction doesn’t have to be forever . Dutton Penguin.
Palkopoulou, E. et al. 2015. Complete Genomes Reveal Signatures of Demographic and Genetic Declines in the Woolly Mammoth. Current Biology 25, 10, 1395-1400 . DOI: 10.1016/j.cub.2015.04.007.
