We all know about the famous sci-fi film “Jurassic Park (1993) directed by Steven Spielberg. Dinosaurs became extinct about 65 million years ago. The film depicts an imaginary scenario in which dinosaurs could be resurrected by cloning of dino DNA trapped on a drop of dino blood inside a prehistoric mosquito specimen preserved in amber. It’s a highly unlikely situation that DNA could be preserved intact that long under these circumstances.
What if Jurassic Park can be created in real life? How? For what purpose? What are the pros and cons?
Today, let’s discuss the recent initiatives towards the de-extinction of some of the world’s lost species.
Colossal Biosciences enter the scene
Colossal Biosciences, a Dallas, Texas, US-based company is contemplating the use of Crispr-Cas9 technology to bring back some of the long-lost species. It had already announced that it began work for resurrecting two species-the wooly mammoth and the Tasmanian tiger (thylacine). The company recently added a third species to its de-extinction bucket list: the dodo bird.
Dodo (resembling a duck) was an exotic bird that lived in Mauritius till the middle of the 17th century. The last member of this species died in 1662. It’s a prime example of a species that was exterminated by humans (it was over-consumed for its meat). Its closest living relative is the Nicobar pigeon.
Mechanism of de-extinction
To re-create a version of dodo, Colossal scientists plan to edit genes from the Nicobar pigeon (to make it more like dodo genes). (It’s somewhat like editing an essay on cats to turn it into one on a tiger.) They already know the characteristics of key dodo genes, as the dodo genome has been already sequenced using ancient dodo DNA. Next, they hope to remove germ cells from an egg of a pigeon, edit the genes to make them more dodo-like and implant the cells back into a pigeon egg. Eventually, they hope to create a bird which may not be exactly a dodo but which closely resembles it. However, the reality is still far from the futuristic dream!
Even if a dodo is created in the near future, it would still be a far cry from a real dodo. An animal’s behavior is the result of the complex interplay between genes and environmental factors. The proxy bird would have to learn to survive without other dodo birds to learn from. In the words of Mikkel Sinding, Paleogeneticist, University of Copenhagen, “There is nobody around to teach the dodo how to be a dodo.”
If the resurrected dodo has to be introduced into its original habitat (Mauritius), invasive species introduced to Mauritius would have to be removed before dodos can survive there again, says Beth Shapiro, a lead scientist at Colossal. The dodo may help revive the past ecosystems of Mauritius. Ben Lamm, founder of Colossal thinks that it’s an opportunity for redemption. Humans caused the extinction of the dodo. Now, we may help de-extinct it! However, there are several more issues to be addressed.
Colossal has raised about $225 as venture capital since it launched in 2021.
Species wish-list for de-extinction
Thylacine is one among the lost species that scientists are envisaging to resurrect. The Tasmanian tigers were doglike creatures with stripes that were once widespread across Australia. It disappeared from the mainland around 2,000 years ago. However, they remained in Tasmania until the 1920s, when they were slaughtered by European colonizers who considered them a threat to their livestock. It was, thus, an anthropogenic extinction (and not due to natural causes).
Andrew Pask, is leading a team of scientists working with Colossal to recreate the wolf-like creature and bring it back on Earth. The first step would be to sequence the extinct animal’s DNA (the blueprint for making thylacine written in DNA alphabets: A, G, C, and T). Pask had already accomplished this in 2017. However, the DNA wasn’t completely intact. Over time, DNA degrades into fragments due to the action of UV light and bacteria. Luckily, they had a Plan B too. Thylacine has a close relative, the dunnart (a mouse-sized marsupial). Their DNA sequences are about 95 per cent identical. They compared the two sequences and found out where it was different. Next, they tweaked the genes of the dunnart so they become more like that of the thylacine, using the Capr-Cas9 gene editing technique. It’s like engineering the living dunnart cells almost “magically” into living thylacine cells.
Once the above breakthrough is achieved, they have to turn it into a developing embryo. Then the embryo has to be implanted in the womb of a living close-relative. We have to wait and see if a thylacine embryo develops into a whole living animal!
Another animal in the de-extinction list is the wooly mammoth. It once roamed in the Siberian tundra but it became extinct about 10,000 years ago. Scientists are now trying to slice bits of mammoth DNA into the genome of the Asian elephant (mammoth’s closest living relative) to create a hybrid animal, “mammophant”, that would be adapted to the cold Siberian tundra. Scientists are of the view that introduction of mammoths in Siberia can help in ameliorating climate change by helping revive the pristine ecosystems of the Siberian tundra.
Other animals on the list include the Christmas rat, Pyrenean ibex, Aurochs, gastric-brooding frog, and the passenger pigeon. What about dinosaurs? It’s highly unlikely that dinosaurs can be hacked. As they went extinct long ago (about 65 million years ago), the chances of getting intact dino DNA for sequencing is very low. Without the genetic blueprint, it would be impossible to decipher how to create a dinosaur.
Are we playing God?
Some scientists are posing the ethical question “Just because something can be done, must we do it?” Reintroducing mammoths, dodos, and thylacines might create havoc with existing ecosystems. Some of the plants that wooly mammoths fed on are now long gone. Can mammoths survive on their own in the wild? If not, who will take care of them? Or, should they be kept in zoos solely for human entertainment?
Pros and cons
Some are of the view that bringing back at least certain selected extinct species would be humanity’s contribution towards conservation of wildlife on the planet. Some others think that de-extinction would steal away resources from conservation efforts for endangered species on the Earth.
Nonetheless, fine-tuning Caspr-Cas9 technology through de-extinction projects may lead to many positive impacts. One is the positive effects on our efforts to save threatened and endangered species. Another one could be positive effects on revival of threatened ecosystems. Also, the offshoots of this technology might lead to better repair and regeneration of diseased human tissues and organs; it might even lead to creation of artificial organs such as the heart, lungs, and the kidneys (which may be sold in the supermarket, in the near future)!
(The views expressed are peersonal)
