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In Alice in Wonderland, Lewis Carroll brought the dodo back to life. The extinct, fat, flightless pigeon arranged a famous running race in which “all shall have prizes”.


Now an American tech entrepreneur, Ben Lamm, plans to bring the dodo back to life for real, along with some other extinct species like woolly mammoths, and make a profit while doing so. His firm, Colossal, announced this week that it has raised over $200 million for the project.


The plan raises plenty of questions. Can it be done? Will it be safe? Is it ethical? How will it make money?


Fortunately, a non-profit body, called Revive and Restore, run by the entrepreneur Ryan Phelan and to which I am an advisor, has been thinking through these issues for the best part of a decade.


Until recently, extinction of a species looked irreversible, best summed up in the phrase “dead as a dodo”. The dodo lived on Mauritius and like many flightless birds on islands proved vulnerable to monkeys and cats introduced by people. It went extinct in the mid 1600s. Only a few tatty skins remained.


There was once hope that cloning might resurrect some extinct species, especially flash-frozen mammoths in the permafrost, but the genes are too fragmented. It did not even work for a recently extinct Pyrenean subspecies of ibex.


But even in long dead creatures it has become possible to piece together the DNA jigsaw to read most of the genetic code of long dead creatures.


The passenger pigeon, the thylacine (Tasmanian tiger) and the great auk, which had been gone for a century or so, were soon “sequenced” in this way. The mammoth, dead for a few thousand years, also.


To general surprise in 1997 the Swedish scientist Svante Paabo managed to read the complete genome of a Neanderthal human, dead for more than 40,000 years.


Last year Professor Beth Shapiro of the University of California Santa Cruz read the genetic sequence of a dodo, despite the poor condition of the museum specimens.


Forget Jurassic Park, though: dinosaurs, dead for tens of millions of years, remain inaccessible, their genes having disintegrated long ago. Extracting their genes from mosquitoes in amber made a good plot for a novel, but can’t work in practice.


Getting every last letter of the code right in dodos will still be a challenge. Yet reading the genome may be the easy part.


There’s three more steps that scientists will have to take before living creatures of extinct species can be born. These are currently impossible, but may not be forever.


The first is to edit the genes in a cell from a related living animal to read like those of an extinct species. For the dodo, the closest cousin is the Nicobar pigeon; for the great auk, the razorbill; for the mammoth, the Indian elephant.


The invention of gene editing in 2012 made de-extinction look like it might not always be science fiction.


Current gene editing techniques cannot work accurately on a large scale to make the tens of thousands, maybe millions, of small changes, needed to create a dodo genome out of a pigeon genome.


But in recent years, the new technology of base editing, developed for use in medicine, promises to change that. Within a decade it might be possible to have a pigeon cell containing a complete set of dodo genes sitting in a test tube.


The next step, turning a cell into a bird, looked impossible until a breakthrough a few years ago by Mike McGrew and colleagues at the Roslin Institute near Edinburgh. He worked out how to implant chicken cells in a duck embryo so that when the duck grew up it produced chicken sperm.


One day a domestic pigeon might produce dodo sperm and dodo eggs.


Mammoths will be harder, because you will have to find a womb in which to implant a mammoth embryo, and elephants will reject foreign embryos. Ben Lamm’s Colossal plans to invent the artificial womb along the way, but it won’t be easy.


The final step would be to rear some healthy animals, get them to breed and generate a genetically diverse population capable of surviving in the wild. Many rare species have now been reintroduced to the wild, from sea eagles to beavers.


Besides failure, there is a lot else that can go wrong. For example, the first animals of a de-extinct species might prove to be deformed in some way if a tiny mistake is made in the gene editing.


But many of the objections people raise to de-extinction turn out to be implausible. A de-extinct species will not bring novel diseases back with it. Defrosting mammoth specimens already carries that risk, but editing the genes of elephants to read like mammoth genes carries no risk of contamination.


Some people say the creatures went extinct for a reason, so leave them dead. But the reason was often human greed – we turned great auks into pillow stuffing – or carelessness: the pests that killed dodos were brought by people.


For most of these species, an ecological niche still exists. There’s fish in the North Atlantic for great auks. Thylacines can prey on wallabies. Passenger pigeons can eat acorns.


There is a tree on Mauritius, called the tambalacoque, whose seeds were thought to germinate better if they went through the guts of dodos first.


As for mammoths, some argue that the loss of the mammoth transformed the ecology of Siberia, turning fertile grass steppe into infertile fir forest. Professor George Church of the Massachusetts Institute of Technology thinks that recreating the mammoth steppe could be good news for other species of mammal and bird.


By the way, mammoths would be no more scary or dangerous than African elephants are today: despite their name, they are about the same size.


Then there is the worry that de-extinction would take the pressure off conservationists to save threatened species, but this seems unlikely.


As for the concern that the technologies involved could be used for malicious ends, the point is they are being developed for other purposes anyway: to improve crops or cure diseases. De-extinction would make use of novel techniques rather than invent them.


Of course we need to tread carefully in using biotechnology, and mostly we have strict regulations. But if we are to worry about the risks of biotech, then harvesting wild bat viruses, altering their genes to increase their infectiousness and testing them on human cells in laboratories in the city of Wuhan is where we should focus our concern. All of which happened. A dodo waddling around a forest in Mauritius is far, far less risky.


There is one step that I would never want to see taken, for ethical reasons: bringing back Neanderthal human beings. To keep them in a zoo would be outrageous; to integrate them into society impossible. It would be an ethical disaster.


Ben Lamm’s plans for Colossal are to invent useful things along the way, spin them out and pay for the de-extinction that way. It’s a bit like Steve Jobs’s philosophy of “fake it till you make it”: announce something before you have invented it. It worked for Jobs but is much harder in biotech. Still, that’s for Lamm’s investors to worry about, not the rest of us.


One thing IS for the rest of us to worry about: who is in charge of deciding what can be done? Tech billionaires should not be able to foist dodos on the world without permission from somebody. In that case, it’s really up to the government of Mauritius to come up with regulations about what can be done with dodo genomes. But as de-extinction gets closer, international agreement on regulations will be essential.

By Matt Ridley | Tagged:  environment  evolution