De-Extinction: Back From The Lost World

You’ve met them in history books; have learnt everything about their biological features, lifestyle and social behavior; however, you have never seen them for real. For the simple reason that those species have gone extinct a long time ago, and you were born way too late to pat them on the back. But the tide is turning. A growing number of scientists consider resurrecting forever-gone animals through genetic engineering, hence the term ‘de-extinction’. Did you dream about offering a gigantic mammoth a handful of peanuts? This may soon come true in the labs where the future (and somehow, the past) is getting written.

Cool enough. But how does that work? The species scientists want back from the hereafter look more, these days, like a dog’s feast than exploitable genetic material. Fortunately, researchers have a key to get those animals out of boring museum exhibitions: DNA. As you may remember from your natural science classes, we’re all made up complex strings of DNA, passed on from parent to children via heredity. In other words, one may scold his progenitors for inherited bad eyesight or cruel baldness. (All your biological attributes do not depend solely on heredity, no need to think about parricide.) Plus, scientists are now able to edit DNA with “molecular scissors” – through a complex process known as Crispr-Cas9 – and can thus shape the attributes of future generations.

dna science genetic engineering — This is already fueling a general outcry about *designer babies*, newborns whose traits we could choose before birth (blue eyes: checked, football skills: checked, tall and handsome: checked). This technology could also prevent inherited pathologies to be passed on for generations.

When it comes to de-extinction, bits of an extinct species’ DNA could be reintroduced within its modern-day, distant-relative animal version – like the elephant for the wooly mammoth, although the former was obliged to hair removal through centuries of evolution. Doing so, the genetic modifications induced by the inserted mammoth’s DNA should theoretically give birth to a hybrid creature, half-way between the prehistoric, hairy pachyderm and the peaceful elephant.

First and foremost, researchers must locate genetic heritage left by species they wish to resurrect. Fortunately for them, DNA is estimated to survive thousands of years in the wild, up to millions if placed in ideal preservation conditions. The record goes up to 6.5 million years ago, which brings mankind back to a time when it was only a bunch of chimpanzees, fighting for survival in mosquito-infested forests, with predatory birds and saber-toothed cats on their heels. There is indeed pretty interesting genetic information to collect so as to revive that Lost World.

smilodon saber-toothed tiger — Scientists fight tooth and nail to bring the saber-toothed tiger (*Smilodon*) back. Perhaps it’s the pet of the future. *(Photo: VertebresFossiles)*

Once DNA is extracted – from a (massive) tooth or a chunk of bone, for instance – it can be edited in a lab with the Crispr “scissors” to prepare a new generation of wooly mammoths; but other extinct animals such as dodos, Tasmanian tigers, moas or saber-toothed tigers also top the list. Some enthusiasts hope to go beyond the de-extinction process and wish to resurrect Neanderthals or create scientifically-engineered unicorns, through associating the horn-growing capacity of the rhino with the horse’s genome (sorry to disappoint, the rainbow tail will prove a harder task). However, we can definitely forget the crazy assumptions of a modern-day Jurassic Park; dinosaurs went extinct 65 million years ago, without any genetic footprint left to use.

Finally, gene editing is inseparable from a fierce ethical debate which goes beyond the scientific community. Should we put this groundbreaking technology into practice simply because ‘we can do it’? Should we invest heavily into bringing extinct species back though millions of endangered animals worldwide still require our protection and care? Considering the fortune the entertainment industry could make with such a process, what if it falls into the wrong hands? And last but not least: wouldn’t the future of this brand new biodiversity be threatened if the issues of deforestation, pollution and oblivious hunting that have caused their loss in the first place are not being tackled? Many questions need to be addressed before we make mammoths happen. In the meantime, one should definitely watch Jurassic Park again and wonder about how this would go off the screen.