By Nicky Phillips
March 29, 2013, For more than 3 billion years since single-cell organisms first appeared on the planet, life has evolved in one direction only. When a plant or animal becomes extinct, there is no coming back. Or so we thought.Two weeks ago Australian scientists revealed they had reversed natural selection. Not only had the aptly named Lazarus Project group revived the genome of an extinct species, the gastric-brooding frog, they had also grown embryos containing the bizarre amphibian's DNA - the crucial first step in their attempt to resurrect a dead species.
The head of the team, University of NSW palaeontologist Mike Archer, announced his team's milestone at the TEDxDeExtinction event in Washington in front of international peers pursuing the same goal with other long-dead creatures - the passenger pigeon, woolly mammoth and Spanish ibex.
What stands out about the Australian team, however, is the pace of their progress. While other groups are years, more likely decades, from achieving their goal, the Lazarus team could have a gastric-brooding frog hopping back to life in the next few years.
The precise motivation for reviving a species, a process some call de-extinction, differs among its revivers, but a central theme exists. Aside from ''wow factor'', Archer says, scientists hope their attempt to turn science fiction into reality will help conserve the world's ever-diminishing biodiversity.
Cloning technology could not only bring back extinct species, especially those vanquished by humans, it could also play a vital role conserving critically threatened plants and animals living today.
''If it is clear that we exterminated these species then I think we've got a moral imperative to try to do something if we can,'' Archer says.
As with all endeavours that challenge the natural order of things, de-extinction has critics. Some conservationists fear the ability to revive species from the dead will distract from efforts to rescue the vast number of endangered yet living creatures.
Others wonder what kind environment awaits revived species. If the reason they went extinct in the first place still exists, would we be resurrecting plants and animals only to watch them endure the same fate?
Mike Tyler's first encounter with the gastric-brooding frog came in 1974 when he received a call from a pair of Queensland schoolboys who had collected a frog with a bizarre method of brooding its young.
Female gastric-brooders would swallow their fertilised eggs and transform their stomach into a uterus where the young would metamorphose from tadpoles into baby frogs.
Close to bursting, the mother would then regurgitate her offspring one by one.
''My feeling was that we were looking at something remarkable,'' Tyler, a herpetologist at the University of Adelaide, says.
Tales of the bizarre creature quickly sparked the interest of the medical fraternity, who looked to the species for insights on how to treat stomach disorders.
But, just as this interest piqued, the frog vanished from the wild in 1979, mostly likely a victim of habitat destruction and the human-
spread chytrid fungus that continues to decimate global frog populations today.
When the last two adult frogs Tyler raised in his laboratory died in 1983, the species officially became extinct.
Even though it would be years before scientists would attempt to clone a mammal, let alone an extinct species, Tyler had the foresight to preserve a gastric-brooding frog in his deep freezer.
''I thought it was a very special creature. At least I'd have material other people could use in the future,'' he says.
Forty years later, Tyler told Archer of his frozen specimen. Lazarus' resurrection could begin.
Over the past five years, the team's Monash University genetics specialists, Andrew French and Jitong Guo, have painstakingly inserted single cells containing the DNA of the frozen frog into hundreds of donor eggs from a distant relative, the great barred frog, whose DNA had been deactivated by UV light.
In the beginning, the single cell frog eggs ''just sat there'', Archer says. ''But then, all of a sudden, one of the cells divided, and then it divided again, and again.
''There were a lot of high-fives around the laboratory at that point,'' he says.
The cloning technique, known as somatic nuclear cell transfer, was used in 2003 by Spanish scientists to resurrect a recently extinct native goat - it survived for 10 days - and was similar to the process used to clone Dolly the sheep.
In the lab, the Lazarus cells continued to divide into three-day-old embryos. But then they died.
Genetic tests revealed the embryos, known as blastulae, contained the DNA of the extinct frog so the team are confident their extinct genome is functioning.
''We know not all embryos survive,'' French says.
The quality of the donor egg, injecting the extinct DNA , even the jelly the cells are cultured in can influence their survival, he says. ''The planets just have to align on the day.''
While the team are yet to bring back the bizarre amphibian, their success so far can prevent other frogs from becoming extinct.
''The project is much bigger than the gastric-brooding frog,'' says Simon Clulow, the team's youngest member and expert frog wrangler from the University of Newcastle.
With each species that is extinguished from the planet, a little piece of diversity is lost forever.
But the story need not end there, Clulow says.
If the team succeed in cloning a gastric-brooding frog using a close relative as a scaffold, it demonstrates cross-cloning one species with another is possible.
One of Clulow's greatest passions is advocating for a national gene bank, which stores the tissue of endangered species that could be used to prop up dwindling wild populations or, should the creature go the way of the dodo, allow it to be revived later.
''This project provides irrefutable evidence that gene banking is valid,'' he says.
But for University of Adelaide ecologist Corey Bradshaw, attempts to resurrect extinct animals detract from efforts to conserve critically endangered species because it fails to solve the drivers of extinction.
Species revived from a few specimens would contain little genetic diversity, making them vulnerable to future threats and at risk of becoming extinct all over again.
''It's not solving the real problem,'' Bradshaw says. ''If we encourage this sort of behaviour it's a massive financial distraction.''
Clulow disagrees, saying the Lazarus project was inexpensive compared with other scientific endeavours and the money was donated from entrepreneur and philanthropists such as Dick Smith and geneticist John Shine.
''We haven't touched a cent of public money,'' he says.
With thousands of species around the world under threat - mainly from habitat destruction and disease - Archer wants to assist attempts to save them, not sidetrack them.
''I'm exploring every conceivable initiative that's going to optimise conservation, not only for species that are struggling to survive today but potentially even some of the ones that are lost,'' he says.
What makes a species an ideal candidate for revival depends on who you ask. Most proponents agree the decision needs to consider whether it is technically feasible. Is there functional and intact DNA? Is there a close relative to donate an egg? Also whether it would be practical to re-introduce the animal into the wild.
Given that DNA decays over time, 65million-year-dead dinosaurs will not make a return appearance. Jurassic Park remains science fiction.
Neither would it be sensible to resurrect species whose habitat has disappeared or changed dramatically, says Ryan Phelan, a founder of the Revive & Restore project, part of the non-profit The Long Now Foundation.
The organisation has chosen the passenger pigeon, which once flocked across North America in their hundreds of millions, as its keystone revival species.
The project's leader, Californian geneticist Ben Novak, says many factors make the passenger pigeon a perfect contender. Its genome is shorter and more manageable than mammals and it performed a vital ''biological dance'' within forest ecosystems before hunters blew them from the sky.
''These dense flocks would come into roost, depleting resources, fertilising the ground, letting sunlight in and allow many other animals to flourish,'' Novak says.
But unlike the Lazarus team, who recovered a complete sequence of intact DNA from frozen frog tissue, Novak has only fragments of the passenger pigeon's genetic blueprint. Other groups, including a South Korean team attempting to revive the woolly mammoth, face similar problems.
Even with a full passenger pigeon genome Novak's team would still face the bigger hurdle of how to insert its DNA into a donor embryo and implant that into a surrogate mother, given chicks develop inside hard-shelled eggs.
But the team, which includes world-leading Harvard geneticist, George Church, see these issues as workable challenges.
Their plan, broadly speaking, is to sequence many fragments of passenger pigeon DNA from museum specimens and compare them with the genome of the bird's closest living relative, the band-tailed pigeon, to reveal the extinct bird's most important traits.
This information is then fed into a specialised sequencing technology, developed by Church, which can manufacture parts of the passenger pigeon's genome that can be slotted into the band-tailed pigeon's DNA. If they succeed, the edited sequence could be inserted into the genome of stem cells of another close relative, the common rock pigeon.
These stems cells could then be coaxed to form germ cells - sperm or egg cells - which could then be inserted into the developing embryo of its cousin, in the hope the cells migrate to the chick's sex organs.
If this works, the chick would carry the doctored DNA of the passenger pigeon, and if bred with another such bird would create a chick with passenger pigeon traits. These features could be selected for in subsequent generations until the team produce a bird that is, to all intents and purposes, a passenger pigeon.
''It's my job to bring the passenger pigeon back to life, not as a science novelty or a zoo attract but back into the skies above,'' Novak says.
But reintroducing extinct species into the wild is a concern for some conservationists, who say ecosystems transform, some to a greater extent than others, when species go extinct.
David Bowman, an ecology professor at the University of Tasmania, says bringing back an extinct species raises the same issues as introducing non-natives.
Bowman is not against the idea of introducing foreign species to perform critical roles within an ecosystem - last year he suggested Australia introduce large herbivores such as elephants to contain introduced grass species taking over the continent's centre - but bringing back species from the dead is expensive, and will likely face opposition from the public.
He uses the community angst surrounding the introduction of the beleaguered Tasmanian devil, which remains in the land of the living but only just, onto Maria Island as an example.
''People think the devil might endanger other animals because it's not native to the island,'' Bowman says.
Archer, who previously led an attempt to revive the Tasmanian tiger, has heard all these criticisms before, but he won't be deterred.
''It's the 'You can't do it' zone that attracts me,'' he says.
Giant sloth
When it went extinct: About 11,000 years ago
How: Hunting by humans
Where it lived: The Americas
Size: As long as 20 feet, up to 9,000 pounds
Diet: Ate plants but also scavenged for meat
Random fact: Had claws as long as 20 inches
Why we might be able to bring it back: DNA samples found in fossil dung in Utah
Cuban red macaw
When it went extinct: Last sightings in the late 1800s
How: Hunting, nesting trees felled to capture young birds for the pet trade
Where it lived: Cuba
Size: Approximately 20 inches long
Diet: Seeds
Random fact: Even though its meat was said to smell and taste bad, people still dined on red macaw.
Why we might be able to bring it back: Specimens in Cuba contain DNA samples.
New Zealand giant moa
When it went extinct: Circa A.D. 1400
How: Hunting
Where it lived: New Zealand
Size: As tall as 8 feet, up to 500 pounds
Diet: Probably fed on plants
Random fact: The moa did not have wings.
Why we might be able to bring it back: DNA found in fossil eggs and feathers in New Zealand
Tasmanian tiger (also known as a thylacine)
When it went extinct: Last recorded sighting in the 1930s
How: Hunting, habitat loss
Where it lived: Tasmania, Australia, and New Guinea
Size: Over 4 feet long, around 75 pounds
Diet: Preyed on kangaroos, small rodents, birds
Random fact: People who saw the animal reported that it could open its jaw nearly 180 degrees wide.
Why we might be able to bring it back: Cloning is a possibility with preserved DNA from a specimen at the Australian Museum.
Saber-toothed cat
When it went extinct: Circa at 10,000 B.C.
How: Probably hunting by humans
Where it lived: North and South America
Size: Around 6 feet long, up to 900 pounds
Diet: Preyed on such mammals as bison, deer, horses
Random fact: It's the official state fossil of California.
Why we might be able to bring it back: DNA is preserved in bones at the La Brea Tar Pits in Los Angeles.
Passenger pigeon
When it went extinct: 1914
How: Hunting, habitat destruction
Where it lived: North America
Size: About 15 to 17 inches long
Diet: Seeds, worms, insects
Random fact: The last known bird, named Martha, died at the Cincinnati Zoo.
Why we might be able to bring it back: There are some 1,500 preserved passenger pigeon specimens with extractable DNA.
Dodo
When it went extinct: Late 1600s
How: Mainly because on the island where it lived, newly introduced species like dogs ate chicks and eggs.
Where it lived: Mauritius
Size: About 3 feet tall
Diet: Fruit, seeds
Random fact: Lived only on the small island of Mauritius, east of Madagascar in the Indian Ocean
Why we might be able to bring it back: Two skeletons have been found containing DNA samples.
Woolly mammoth
When it went extinct: About 3,700 years ago
How: Hunting, habitat loss due to climate change
Where it lived: Parts of northern Asia, Europe, and North America
Size: 9 to 11 feet tall, about 1,400 pounds
Diet: Grass and other plants
Random fact: Remains of a 37,000-year-old woolly mammoth calf were found in Russia.
Why we might be able to bring it back: DNA exists in frozen soft tissue.
Should We Revive Extinct Species?
business trends, future scenario, new strategy, people making a difference, powerful idea, scary future, social trends, technology trends March 15th, 2013
For those of you who aren’t familiar with this topic, biotech is currently accelerating four times faster than digital technology, and the revival of extinct species is not only becoming possible, but is imminent. Stewart Brand plans to bring many extinct species back and restore them to the wild with his Revive and Restore Foundation.
Brand is well aware of the moral and ethical controversies surrounding this topic – the can-we-should-we debate – but the issues go far beyond the ethics of de-extinction. What he is proposing is an “unleashing” of human reengineered species that only closely approximate those who have become extinct.
So how long will it be before we see a revived version of the passenger pigeon (extinct in 1914), the Tasmanian tiger (extinct in 1936), and the woolly mammoth (extinct over 3,000 years ago) roaming the earth again?
It will probably come as a surprise to most to learn that the first revival of an extinct species has already occurred. It happened in 2003 when scientists cloned a bucardo, an Iberian wild goat, that had gone extinct three years earlier, by inserting its DNA (which they got from frozen bucardo skin) into the eggs of an existing goat. The cloned bucardo was born, but then died just ten minutes later.
To put this into perspective, the Wright Brother’s first flight only lasted 12 seconds.
Perhaps the most controversial comment made by Brand during his talk was, “the results won’t be perfect but nature isn’t perfect, either.”
So we will only be creating close proximities to existing species, effectively new forms of life. Here are a few thoughts on what comes next.
Should cloning be used for de-extinction?
In its earliest form, de-extinction will involve cloning DNA, which means it will raise a number of ethical questions, like “Should we be playing God?”
According to Brand’s Revive and Restore Foundation, there are four primary reasons for reviving extinct species:
- To preserve biodiversity and genetic diversity.
- To undo harm that humans have caused in the past.
- To restore diminished ecosystems.
- To advance the science of preventing extinctions.
So should we only focus on species where human played a role in their extinction? The unanswered questions go far beyond that.
As an example, if California condors go extinct, it’s unclear if they could ever be brought back fully, because young condors rely on their parents for training.
Will a revived species learn to adapt to its new environment? Will they be able to reproduce in sufficient number to ever be fully viable? Will the genetic differences be too great for them to survive, or will those differences make them ultra-adaptable where they will thrive to the point of becoming a pest to their surroundings.
Three Possible Techniques
Around the same time as the attempted revival of the bucardo in 2003, Robert Lanza, Chief Scientific Officer at Advanced Cell Technology, took tissue from a Javan banteng (not yet extinct), and inserted it into an egg cell of a closely related cow. The cow gave birth to the exotic banteng, which is still alive and thriving.
The cloned Javan banteng
Currently there are three semi-successful techniques being experimented with for de-extinction.
1.) Selective back-breeding of existing descendants to recreate a primordial ancestor is being used for the revival of the European Aurochs, among others.
2.) Cloning with cells
from cryopreserved tissue of a recently extinct animal can generate
viable eggs. If the eggs are implanted in a closely related surrogate
mother, some pregnancies produce living offspring of the extinct
species.
3.) Allele replacement for precision crossbreeding
of a living species with an extinct species is a new genome-editing
technique developed by Harvard geneticist, George Church. If the
technique proves successful (such as with the passenger pigeon), it
might be applied to the many other extinct species that have left their
“ancient DNA” in museum specimens and fossils that are thousands of
years old.
Over the coming years many new techniques will undoubtedly come to life making it one of the hottest new areas of science. Reviving Extinct Humans
Resurrecting lost plants and animals are one thing, but when it comes to tampering with humans the stakes get much higher.
Here are a few examples of of the ethical dilemas we will be facing:
- Could a young woman introduce the DNA of her own grandmother to her own eggs and essentially give birth to a baby ancestor?
- If women could purchase the DNA of famous people, world leaders of the past, or top scientists, how many would be willing to pay for genetic material from the likes of Abraham Lincoln, JFK, Paul McCartney, Richard Branson, or Steve Jobs?
- By combining human and animal DNA, is it possible to create super-human DNA?
Driven by ROI
Very often what starts as a cause, to right the wrongs of the world, will get hijacked by businesses wanting to profit for the new technology. Moral and ethical edges of science are often vastly different than the lines businesses are willing to cross.
Genetic research like this is very expensive, and this recent awareness campaign will undoubtedly draw in millions.
However, the same people funding today’s research are often the same people wanting to recoup their investments, and the lens through which they are viewing the work is vastly different than the lens of scientists doing the research.
Certainly the moral divide, created by the chasm between knowledge-seekers and profit-seekers, varies on a case-by-case basis. It can range from non-existent to something very wide. But without good systems for governing research and outcomes, it may be wise to focus on the lack the checks and balances needed to prevent large-scale disasters.
Final thoughts
The 1993 movie Jurassic Park did a great job of sensitizing the world to the idea that de-extinction may indeed be possible. As a result, many scientists decided to make it their mission in life.
While we will see some early successes over the next ten years, we will also see many setbacks. As Brand puts it, “De-extinction is not a ‘quick fix’ science. Most species revival projects will take many decades.”
At the same time, the sum total of all human knowledge is massively dwarfed by what we don’t know, and very often our attempts to control the world around us goes very wrong.
A good example of this was given by Allan Savory, an ecosystem scientist working in Africa when he recommended the slaughter of 40,000 elephants to help prevent desertification, only later to realize that elephant grazing itself was highly beneficial to thwart the encroachment of the desert.
Brand ended his talk with, “Humans made a huge hole in nature, and we have a moral obligation to repair the damage.”
Will the world be a better place if we bring some of our extinct animals back? Are the close proximities of animals that Brand describes close enough, or is this a dangerous area to be playing in? I’d love to hear your thoughts?
UPDATE: On March 15, 2013, researchers announced that they’ve grown early-stage embryos of the gastric-brooding frog, a species that has been extinct since 1983. This is the first time, scientists have grown the embryos of an extinct species. Details in the Sydney Morning Herald.
By Futurist Thomas Frey
Author of “Communicating with the Future” – the book that changes everything
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