Scientists on brink of reviving extinct animals

Researchers have claimed they are on the brink of resurrecting a lost species of frog. Dodos and sabre-toothed tigers could soon follow. But is it wise to meddle with life and evolution?

On March 22nd 1900, a young boy was playing with an air gun near his home in Ohio’s Appalachian Mountains. When a handsome red-breasted bird settled on a branch nearby, the boy took aim and fired, killing the animal instantly. The bird was a passenger pigeon – the last of its kind ever spotted in the wild.

Passenger pigeons were once so common in America that flocks of them were said to block out the sun. But when Europeans arrived, their abundance became a curse: the huge gatherings were easy pickings for hunters with guns and pigeon was soon the cheapest meat on the market. By 1915, the species had disappeared forever.

Or so it was believed. But now, a controversial group of scientists claim that we are on the verge of bringing the passenger pigeon back from the grave. And it could be joined by a hoard of other lost species: dodos, sabre-toothed cats, Tasmanian tigers and even woolly mammoths have all been suggested as realistic candidates for so-called ‘de-extinction’.

It won’t be an easy task – resurrecting an extinct animal is just as complex and daunting as it sounds. But it is not impossible.

In 2003, scientists injected the wombs of 57 goats with genes from an extinct species called the Pyrenean ibex, and watched with hope as fetuses began to form. Six goats miscarried, but one ibex survived, and for an hour the species returned from the dead, before sadly dying from a deformed lung.

Scientists had an advantage with the Pyrenean ibex, since they had preserved the final specimen’s DNA. In most cases DNA is only preserved in the bodies of long-dead specimens, where it is certain to have decayed.

But researchers at the Lazarus Project have found a solution. They plan to gather fragments of DNA from many sources and splice it together to produce as full a genome as they can. Any missing fragments will be provided from DNA of the nearest surviving relative – in the mammoth’s case, for example, an elephant.

Dodo or don’t do?

Within a generation, Earth could be teeming with wondrous creatures that we believed to have disappeared for good – very often due to humanity’s own destructive power. We could swim with river dolphins, walk with mammoths, scramble dodo eggs for breakfast. ‘Humans have made a huge hole in nature,’ says one scientist. ‘Now we have the ability, and maybe the moral responsibility, to repair some of that damage.’

But some conservationists are horrified: this narcissistic meddling with life is no way to atone for our sins, they say. What’s gone is gone; instead of playing God, we should focus on preserving the 17,000 surviving species that are on the verge of following the mammoth to the graveyard of evolution.

You Decide

  1. Should scientists try to revive extinct animals like mammoths and dodos?
  2. When paleontologist Michael Archer is accused of playing God in his efforts at de-extinction, he replies: ‘I think we played God when we exterminated these animals.’ Is this a fair and satisfactory response?

Activities

  1. Choose an extinct animal and write a brief profile on one A4 page.
  2. Do some research and describe what scientists mean when they talk about ‘splicing DNA’. Include a diagram in your explanation.

Some People Say...

“It’s natural for animals to die out: that’s just evolution running its course.”

What do you think?

Q & A

So Jurassic Park could soon be a reality?
Dinosaurs are probably a step too far. For de-extinction, scientists need access to a full and intact strand of DNA. That rules out animals that disappeared more than a few thousand years ago, and it’s 65 million years since the last dinosaur died.
What could we gain from de-extinction?
There could be some scientific benefits. The animal currently closest to resurrection, for instance, is a frog which broods its young in its stomach. By examining this species, scientists could gain insights into how reproduction works. But for most people that’s not the main motivation.
Then what is?
A desire to undo the damage we have caused and to add to the rich variety of life on Earth. ‘What intrigues me,’ as one researcher says, ‘is just that it’s really cool.’

Word Watch

Dodos
The dodo was a flightless bird with a huge beak which lived on the Pacific island of Mauritius. Dutch sailors landed on the island in 1598, and within 70 years every dodo had been killed for food.
Sabre-toothed cats
Also called sabre-toothed tigers, this is not actually one animal but a group of species distinguished by their long, curved teeth. They are thought to have died out around 11,000 years ago due to changes in the climate.
Tasmanian tigers
This marsupial, scientifically known as a ‘thylacine’, was famous for the striking stripes on its back. The thylacine has almost certainly become extinct since humans arrived in Australasia, although some claim to have witnessed survivors.
Woolly mammoth
Humans may have contributed to the mammoth’s extinction (they certainly ate it and used its bones), but most scientists blame climate change first and foremost. Because they were huge and inhabited icy areas, mammoth remains are uniquely well-preserved.
DNA
Deoxyribonucleic acid is the molecule that forms the genes of every organism, providing the code (or recipe) for life.
Lazarus
In the Bible, Lazarus of Bethany is a character whom Jesus resurrected four days after his death.
Genome
The genome is the sum of all an organism’s genetic information.

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