Endangered horse cloned from frozen cells

Reborn: The cloned horse was born on the 6 August to a surrogate mother in Texas, US. © Scott Stine

Should we bring back extinct species? Cells preserved for 40 years have been used to clone an endangered wild horse, but some scientists ask whether cloning is really the solution.

Kurt is one of a kind. The latest video of this newborn Przewalski’s horse shows him frolicking happily next to his mother. But she is not his genetic parent. He is an exact copy of his father and the world’s first cloned wild horse.

The foal is named after Kurt Benirshke, the founder of the Frozen Zoo in San Diego, California. Forty-five years ago, Benirshke began freezing the cells of endangered species long before cloning technology existed.

In 1996, Dolly the sheep became the first mammal to be cloned. Today, improved science makes it possible to save animals that disappeared hundreds or thousands of years ago. Gene editing could now allow scientists to edit an elephant’s DNA to make a woolly mammoth.

However, some doubt whether we should be cloning animals at all. The prospect of safari parks populated by mammoths and sabretooth tigers may sound exciting but could lead to the prehistoric disaster imagined in Jurassic Park.

Palaeontologist Michael Archer says “we have an obligation” to reverse the mass extinction caused by humans over the last 10,000 years.

But many species are threatened or have died out because of a loss of habitat. Environmental philosopher Glenn Albrecht argues that bringing these animals back without restoring their ecosystems makes no sense.

Should we bring back extinct species?

A new lease of life

Some say no. Natural selection means the strong survive, and the weak die out. Cloning interferes with this process. Even if these cloned animals do survive, they will disrupt existing ecosystems and endanger other species.

Others say yes: our planet depends on reversing the rate of extinction. Humans have degraded habitats and killed off thousands of species. By diversifying the gene pool, cloning may safeguard the future of life on Earth.

You Decide

  1. What endangered or extinct animal would you clone?


  1. Draw your own safari park of extinct animals brought back to life.

Some People Say...

“In pushing other species to extinction, humanity is busy sawing off the limb on which it perches.”

Paul R. Ehrlich, American biologist

What do you think?

Q & A

What do we know?
It is generally agreed that the rate of species extinction is accelerating. Ten thousand years ago, roughly one species disappeared every month, but conservationists believe human activity is now wiping out between 150 and 200 species every day. There are over 32,000 critically endangered species, including the European hamster, the North Atlantic right whale and several species of lemur.
What do we not know?
One main area of debate is around whether a clone is the same as the original. Identical twins are genetic clones, but nurture and experience raise two separate individuals. And although cloning technology can potentially edit an elephant’s DNA to look like a mammoth, is the cloned mammoth the real thing? Some argue that an animal only exists as part of an ecosystem and a cloned animal is just an exotic curiosity, without the habitat in which it evolved.

Word Watch

Przewalski’s horse
This species split from the domestic horse 45,000 years ago and was once thought to be the only surviving species of wild horse. Recent studies now suggest the Przewalski’s horse is descended from an animal domesticated by the Botai culture of Central Asia, 5,500 years ago.
Woolly mammoth
Once common in the northern hemisphere, the last of these furry giants died out around four thousand years ago. Because so many carcasses were frozen during the Ice Age and preserved in the permafrost, they offer scientists the best opportunity to resurrect a prehistoric beast.
Jurassic Park
Geneticists often complain that the 1993 dinosaur disaster movie is mentioned whenever people debate animal cloning. They say the tyrannosaurus rex died out 65 million years ago, left no genetic material behind and won’t be coming back.
Someone who studies the fossilised remains of extinct species. Scientists have estimated that as many as four billion species have lived on Earth and 99.9% of them are now extinct.
Biological communities of interacting organisms and their physical environment.

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