Rais­ing the dead

Two decades af­ter Steven Spiel­berg’s film first ter­ri­fied view­ers and con­vinced many that T-Rexes and ve­loci­rap­tors could walk the Earth again, sci­en­tists have been able to bring to life em­bryos of an ex­tinct frog. So are di­nosaurs next? Mike Peake re­por

Friday - - The Big Story -

He may have looked strangely cute or wor­ry­ingly toothy – de­pend­ing on your viewpoint – but the baby ve­loci­rap­tor that was helped out of its shell by a coo­ing John Ham­mond in the hit 1993 film Juras­sic Park would be 21 if he were around to­day.

Com­ing of age in 2014, the movie’s youngest star would now be a pack-hunt­ing, meat-lov­ing, red-blooded adult – as­sum­ing, of course, that he’d sur­vived any roam­ing T-Rexes. And, ahem, that any of this was real.

The ini­tial flurry of ex­tinc­tion-bust­ing pos­si­bil­ity that fol­lowed Steven Spiel­berg’s di­nosaur block­buster quickly faded as sci­en­tists – as op­posed to nov­el­ists and screen­writ­ers – rushed to ex­plain that the ba­sis of the movie was ac­tu­ally a load of tosh. Yes, we’d made great strides in our un­der­stand­ing of ge­net­ics and of DNA in par­tic­u­lar, but no, we weren’t go­ing to be suck­ing any 150-mil­lion-year-old di­nosaur blood out of a mos­quito pre­served in am­ber any time soon. The world went on its way.

But 21 years in mod­ern sci­ence is a long time, and what might have been dis­missed as im­pos­si­ble in 1993 is, well, now still nowhere nearer hap­pen­ing – al­though some sci­en­tists are claim­ing that there might be a dif­fer­ent way to do it: by de-evolv­ing birds back into di­nosaurs.

All of us carry our evo­lu­tion­ary his­tory deep in­side us, which means it is pos­si­ble – in the­ory at least – to switch our dor­mant genes back on. And as the sci­en­tific com­mu­nity now ac­cepts that birds are the di­rect de­scen­dents of the rather more large and scary beasts that once roamed the Earth, it doesn’t take too big a leap of faith to imag­ine a lab team trans­form­ing a par­rot into some­thing a bit more ptero­dactyl.

As strange as it sounds, it turns out that this may ac­tu­ally be a much more plau­si­ble route to Dino 2.0 than pok­ing around in am­ber – al­though re­searchers have found a mi­nus­cule fe­male mos­quito that could be at least 46 mil­lion years old, fos­silised in a piece of shale in Mon­tana, US.

What’s even more in­ter­est­ing: sci­en­tists found the last blood meal it had eaten still in­tact in the in­sect’s dis­tended belly. Un­for­tu­nately, the mos­quito was buzzing around in swampy lands long af­ter the mighty an­i­mals roamed the Earth so there’s no chance of any of its meal be­ing dino-flavoured. But don’t get dis­heart­ened. For starters, let’s be­gin with… Juras­sic Frog.

Ac­tu­ally, call­ing this resur­gent rep­tile ‘Juras­sic’ would be stretch­ing things a lit­tle, but the gastric-brood­ing frog (fa­mous for swal­low­ing its eggs and then giv­ing birth through its mouth) re­ally is ex­tinct, hav­ing died out in 1983 af­ter ap­par­ently catch­ing a fatal disease that stems from a fun­gus spread by hu­mans. And that’s what makes the fact that a team of Aus­tralian sci­en­tists re­cently suc­ceeded in cre­at­ing liv­ing gastric-brood­ing frog em­bryos so re­mark­able.

The sci­ence be­hind their work is cer­tainly con­tro­ver­sial, with crit­ics claim­ing – just as Jeff Gold­blum’s Dr Mal­colm char­ac­ter did in Juras­sic Park – that ex­tinct species have al­ready had their chance and should not be brought back to life. Un­de­terred, the pro­fes­sors at the Univer­sity of New­cas­tle in New South

Wales – in­clud­ing ‘frog whis­perer’ Pro­fes­sor Michael Ma­hony and cloning spe­cial­ists Dr An­drew French and Dr Ji­tong Guo – re­cov­ered cell nu­clei from frozen tis­sues of the long-gone frog and im­planted them into spe­cially pre­pared eggs from a dif­fer­ent frog species.

Af­ter hun­dreds of at­tempts, they achieved the im­pos­si­ble and saw the em­bryos start to grow. Al­though none of the em­bryos sur­vived more than a few days, ge­netic tests con­firmed they were full of the ge­netic ma­te­rial from the ex­tinct species.

The fledg­ling frog­gies may have never quite made it to the tad­pole stage, but what clearly did have legs was the sci­ence it­self: the em­bryos were swim­ming with brand new, freshly cre­ated DNA from the ex­tinct gastric-brood­ing frog.

“This project and oth­ers like it are in­spir­ing oth­ers to imag­ine what was once re­garded as unimag­in­able – that ex­tinc­tion might not, in fact, be for­ever,” says palaeon­tol­o­gist Pro­fes­sor Mike Archer of the Univer­sity of New SouthWales, who over­saw the work of the New­cas­tle sci­en­tists. Their work has been dubbed The Lazarus Project – and it has thrown a fire­work un­der the pos­si­bil­i­ties of ge­netic ma­nip­u­la­tion and where it might head next.

“We re­ac­ti­vated dead cells into liv­ing ones and re­vived the ex­tinct frog’s genome – an or­gan­ism’s hered­i­tary in­for­ma­tion – in the process,” says Archer, whose team’s work was in­cluded in Time mag­a­zine’s 25 Best In­ven­tions of the Year 2013. “We’re in­creas­ingly con­fi­dent the hur­dles ahead are tech­no­log­i­cal and not bi­o­log­i­cal, and that we will suc­ceed.”

And frogs, it seems, are just for starters. By his own ad­mis­sion, Archer’s real am­bi­tion lies in bring­ing some­thing back on a much grander scale. He has his eye on some­thing called a thy­lacine.

More com­monly known as the Tas­ma­nian tiger, the thy­lacine has roots dat­ing back 25 mil­lion years. A dog-like mar­su­pial with a stripy back and a long mouth, it dis­ap­peared in the 1930s, hav­ing been seen off by din­gos and, at the very end, by trig­ger-happy hu­mans.

For Archer, this tragic furry beast has be­come some­thing of an ob­ses­sion be­cause its demise high­lights how the coloni­sa­tion of Aus­tralia ad­versely af­fected the bal­ance of na­ture. He wants to bring the thy­lacine back to life.

“If it’s clear that we ex­ter­mi­nated cer­tain species, then we not only have a moral obli­ga­tion to see what we can do about it, but a moral im­per­a­tive,” he told a cap­ti­vated au­di­ence last year at the TED De-ex­tinc­tion Con­fer­ence in­Wash­ing­ton. “We’re try­ing to re­store the bal­ance of na­ture that we have up­set.”

Af­ter track­ing down a pick­led thy­lacine pup – it had been pre­served in al­co­hol for more than 100 years – at the Aus­tralian Mu­seum in Syd­ney, Archer de­cided to try to ex­tract some of its DNA and see if he could set about ‘de-ex­tinct­ing’ the species.

Ini­tial tests showed, how­ever, that the sam­ple had been heav­ily con­tam­i­nated, hav­ing been plucked out of its jar for in­spec­tion by in­nu­mer­able cu­ri­ous mu­seum cu­ra­tors over the years. “What we didn’t want to hap­pen was to put this through the ma­chine and have a wiz­ened old cu­ra­tor pop out the other end,” laughs Archer.

Hav­ing even­tu­ally found bet­terqual­ity DNA in the pup’s teeth, Archer be­gan to har­bour hopes that it could one day be trans­ferred into the egg of a host species, such as a Tas­ma­nian devil, a car­niv­o­rous mar­su­pial now found in the wild only in Tas­ma­nia.

“Is this a risk?” he asks. “Are we go­ing to get a Frankenstein? No. Be­cause if the only nu­clear DNA that goes in is from the thy­lacine, the only thing that comes out at the other end is thy­lacine.”

Archer points out that the tech­nique used to bring to life the frog em­bryos – So­matic-Cell Nu­clear Trans­fer, or SCNT – has also been used to briefly bring the ex­tinct Ibe­rian Ibex (a deer-like mam­mal with large horns) back from the dead.

“Nu­clei from body cells of the last in­di­vid­ual an­i­mal af­ter it had died were trans­ferred into the egg cells of a goat,” he ex­plains. “And it re­sulted in a new Ibe­rian Ibex. Al­though ge­net­i­cally iden­ti­cal, it died shortly af­ter birth fol­low­ing com­pli­ca­tions with its lungs. That re­search is start­ing again, so hope­fully there’ll be an even bet­ter out­come next time.”

All of which leaves some­thing of a ques­tion mark over the whole con­cept of con­ser­va­tion­ism. Why save the panda, for ex­am­ple, when sci­en­tists could sim­ply knock up a few new ones when we run out? It’s a com­plaint that Archer hears a lot.

“I think that ar­gu­ment is silly for three rea­sons,” he as­serts. “First, bring­ing ex­tinct an­i­mals back suc­cess­fully hasn’t been done yet, so take a deep breath. Sec­ond, ef­forts

to do this, whether suc­cess­ful or not, would oc­cur in par­al­lel with mod­ern con­ser­va­tion; it’s not an al­ter­na­tive.”

Fi­nally, he says, the cloning tech­niques de­vel­oped to as­sist de-ex­tinc­tion projects will be use­ful to en­able en­dan­gered species to have their num­bers in­creased. Trans­la­tion: stick rare panda DNA – via SCNT – into the eggs of a non-en­dan­gered rel­a­tive and… bingo!

It’s a fas­ci­nat­ing sub­ject – and this is just the tip of the ice­berg. For Dr David Pen­ney, a palaeon­tol­o­gist at the UK’s Univer­sity of Manch­ester, the real buzz comes from the sci­ence’s Juras­sic Park im­pli­ca­tions.

“I was once a kid fas­ci­nated by di­nosaurs, I have di­nosaur mod­els in my of­fice and I would love to see a di­nosaur!” he en­thuses. “We try to bring back re­cently ex­tinct species, so re­ally – what’s the dif­fer­ence?”

On a prac­ti­cal level, how­ever, he points out that the am­ber from which di­nosaur blood was ex­tracted in Juras­sic Park was ac­tu­ally from a time pe­riod well af­ter the di­nosaurs’ reign – mil­lions of years later. He also ad­mits that the chance of get­ting “dino DNA” – as they say in the film – from older am­ber sam­ples now seems “a highly un­likely propo­si­tion”.

Most fos­sils of in­sects that have been pre­served in am­ber are un­likely to con­tain di­nosaur blood be­cause the mam­moth beasts that once roamed the planet had be­come ex­tinct by the time the in­sects were trapped.

Also, many in­sects de­cay from the in­side out af­ter they’re trapped, leav­ing lit­tle for sci­en­tists to try to ex­tract and study. The sam­ple would have to be ex­tremely dry, be­cause DNA can break down quickly if con­tam­i­nated by wa­ter.

Now, sup­pose sci­en­tists did find a pre­served mos­quito that had gorged on dino blood? It’s an ex­tremely un­likely pos­si­bil­ity, but even if it hap­pened sci­en­tists would have their work cut out try­ing to ex­tract any di­nosaur DNA be­cause it would be sur­rounded by the DNA of the host in­sect. Also, the DNA from other cells in the am­ber could con­tam­i­nate the sam­ple, ren­der­ing it use­less.

The ‘sci­en­tists’ in Juras­sic Park got around such hur­dles by com­bin­ing di­nosaur DNA with frog DNA. But this would be like try­ing to put to­gether a jig­saw puz­zle us­ing bil­lions of pieces that come from two dif­fer­ent puzzles, say sci­en­tists.

But sci­ence charges on, and Dr Pen­ney says that DNA ex­trac­tion tech­niques are get­ting more pre­cise all the time. And if it’s di­nosaurs you’re af­ter, maybe you’ve only to open your eyes and look around you…

“Di­nosaurs don’t need to be de-ex­tincted,” says Archer, “be­cause there are more of them liv­ing on the planet to­day than hu­mans. Birds are di­nosaurs, the only group of di­nosaurs that didn’t suc­cumb to the me­te­oric dis­as­ter that wiped the oth­ers out 66 mil­lion years ago. In fact, most of the clas­sic, car­niv­o­rous di­nosaurs were ac­tu­ally feath­ered and would have looked like birds on steroids.”

If that’s not enough, he of­fers a few fi­nal words of so­lace. “There’s no rea­son we can’t work back through a liv­ing chicken’s genome and re­turn their sup­pressed di­nosaurian teeth, wrist and an­kle bones. In fact, that’s al­ready been done in lab ex­per­i­ments.”

Ox­ford bio­chemist Dr Ali­son Wool­lard, talk­ing to the UK’s Daily Tele­graph, adds, “We know birds are di­rect de­scen­dents of di­nosaurs, as proven by an un­bro­ken line of fos­sils that tracks the evo­lu­tion of the lineage from crea­tures such as the ve­loci­rap­tor or T-Rex through to the birds fly­ing around to­day.”

This evo­lu­tion, she says, sug­gests that deep within the DNA of to­day’s birds are the dor­mant genes that con­trol their long-sup­pressed di­nosaur char­ac­ter­is­tics.

“In the­ory, we could use our knowl­edge of the ge­netic re­la­tion­ship of birds to di­nosaurs to de­sign the genome of a di­nosaur,’’ said Dr Wool­lard.

Like Pro­fes­sor Archer, she too won­ders if one day in the near fu­ture we will be able to switch the di­nosaur genes ly­ing dor­mant in birds back on.

So if you’re lis­ten­ing, Mr Spiel­berg, think on. Juras­sic Chicken, in which a gi­ant toothy rooster ter­rorises a sub­ur­ban shop­ping mall. We’ll be the first in the cin­ema queue.

Could real life fol­low movies? Sam Neill in

Juras­sic Park III

The Gastric Brood­ing Frog is in

the spot­light

Juras­sic Park sci­ence re­ally was out of this world, say

the real sci­en­tists

Pro­fes­sor Mike Archer has de­signs on bring­ing the Tas­ma­nia

tiger back to life

Could a mos­quito’s last meal help to bring back

ex­tinct crea­tures?

THE BIG STORY Dr David Pen­ney would love to see di­nos walk on

Earth again

Might the Tas­ma­nian devil, above, help to bring back this Tas­ma­nian tiger?

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