WHY IS IT SO?

How species de-extinction works

How on earth will he do it? The answer lies with the molecules of deoxyribonucleic acid, or DNA, unique to every living being. Within the DNA are “instructions” on how an organism will look and function. Church and his team plan to take DNA from the bodies of mammoths trapped in ice or permafrost somewhere between 4,000 and 10,000 years ago. There are many mammoths long frozen in the ice of Siberia that modern scientists have found and preserved in laboratories. From these specimens scientists can extract the DNA to de-extinct the species.

The problem is that after an organism dies its DNA tends to break up and degrade. DNA has a half-life of 521 years, which means that if we take a strand of DNA now and wait 521 years, only half of it will still be intact.. The last living mammoth died roughly 4000 years ago and many of the specimens scientists have are much older than that. So while we have whole bodies of mammoths, we don’t have whole copies of their DNA.

So how do you fix that? Here comes the Asian elephant to the rescue! By using the DNA of this elephant, the mammoth’s nearest living relative, scientists can patch up the holes in the mammoth DNA to produce a whole DNA sequence capable of creating a live mammoth.

The Harvard team are using the new and incredibly exciting gene-editing technology called CRISPR to do this. CRISPR – short for “Clustered regularly interspaced short palindromic repeats” – is the most precise, easiest and least expensive way to take genes and put them wherever you like.

Genes are short sections of DNA responsible for particular characteristics of an organism, such as hair colour or ear size. This amazing technology will enable scientists to take the mammoth genes and insert them into the DNA of Asian elephants to produce a complete sequence. After that, the DNA will be placed inside an egg cell of an Asian elephant, and from this will grow a live mammoth. Church and his team believe they can do this by 2019, just two short years away.

But hold on! If you’re mixing mammoth and elephant DNA, do you really get a woolly mammoth?

Well, sort of. What you really get is a “mammophant”, a hybrid of a mammoth and an elephant. It would totally look like a mammoth, though, with long tusks, small ears and long shaggy fur. It would even have some other mammoth traits, such as blood adapted to very cold weather. So although it might not be exactly like the woolly mammoths of the past, it will be pretty close – and half a mammoth is better than no mammoth at all, right?

If scientists can de-extinct a mammoth, it should be possible to bring other extinct species back to life. Around the world, researchers have begun work on de-extincting the dodo, the auroch (a super-huge ancestor of the modern cow), a long-lost species of zebra, cave lions and lots more. Mike Archer of the University of New South Wales and some colleagues are investigating how to resurrect the Tasmanian tiger.

But even if we can de-extinct species that have died out, should we bring back the mammoth? It’s a tricky question. Mammoths, like elephants, were a social species, needing the company of other members of their own kind. If we only brought one individual back to life, wouldn’t it get terribly lonely? Perhaps over time scientists could create a large number of mammoths so they have friends to socialise with. But then we’d have a huge herd of big, powerful, hungry mammoths. Where will they live?

There actually might be an answer to that. There is already a place called Pleistocene Park in north-eastern Siberia where scientists have recreated much of the ecology that would have existed during the last Ice Age. This has been achieved by returning the area to tundra grasslands, on which mammoths would have grazed 10,000 years ago. So it is here scientists are thinking of releasing mammoths into the wild.

One big question is whether it is possible to deextinct a dinosaur. Can we finally make Jurassic Park a reality? Unfortunately the answer seems to be “no”.

Where the mammoth has been extinct for 4,000 years and the thylacine for less than 100 years, dinosaurs have been extinct for more than 65 million years. Given DNA’S half-life is 521 years, it is nearly impossible for enough genetic material to remain intact for scientists to use to de-extinct a dinosaur.

So a Jurassic Park must remain on our movie screens for now. Instead, we will have to make do with Pleistocene Park. It might not have a T-rex, but it could have mammoths – and that’s pretty awesome.