Cloning in conservation: vital lifeline or dangerous distraction?
Only a month ago, researchers at the National Black-Footed Ferret Conservation Centre in the US celebrated the first birthday of Elizabeth Ann, the first cloned black-footed ferret. This celebration marked the latter as one of the first clones of an endangered species to reach sexual maturity. As the clone of a female ferret, named Willa that died 35 years ago, researchers now hope to mate Elizabeth Ann with a carefully selected male ferret in an effort to increase the size of the endangered species population and introduce greater genetic diversity.
Today, all the black-footed ferrets descend from a small sample of seven ferrets, making them vulnerable to disease and deformations. This also means that genetic variation in this species has declined by 55% since 1985 when conservationists captured the last known wild black-footed ferrets to start a captive breeding programme.
Willa’s DNA has ten times more unique alleles than the DNA of any of 10,000 captive-bred ferrets
If Elizabeth Ann gives birth to healthy kits, this will be the first time that conservationists successfully use cloning as a method of conservation. Conservation biologists believe that adding Willa’s genes to the black-footed ferret’s gene pool via her clone would “pack a huge biodiversity punch” (Ben Novak, lead for Revive and Restore) as genome analysis found that Willa’s DNA has ten times more unique alleles than the DNA of any of 10,000 captive-bred ferrets.
This success could increase efforts to clone other endangered species and further help establish cloning as a conservation tool. However, failure could reinforce scepticism over the use of cloning for conservation; criticism of this method includes its cost and its ethics. Furthermore, many conservationists worry that cloning distracts from more conventional methods of conservation and the cause of endangerment to species.
Cloning efforts date back from 1885 with the first ever demonstration of artificial embryo twinning and in 1996 Dolly the sheep became the first mammal to be cloned from an adult cell. However, cloning endangered species is a more recent effort; whilst the first clone of an endangered species was born on the 8th of January 2001, the baby gaur (a bovine native to south and southeast Asia) died two days later. Subsequent efforts came later with Kurt, a clone of an endangered Przewalski’s horse, born in September 2020.
However, the reports of successfully cloning endangered animals are the few high-profile successes among the many failures. For example, conservation biologists attempted to clone the Pyrenean Ibex three years after it went extinct using an old frozen skin sample.
Researchers impregnated over 200 domestic goats, seven became pregnant, only one made it to term, but the baby goat died minutes after it was born. Overall, less than one percent of wild clones survive. This is because cloning often leads to a higher risk of birth defects and susceptibility to illness.
Cloning a cheetah would cost over $100,000
Efforts to clone other species continue to be underway but it is safe to say that cloning still has much progress to make before becoming a reliable tool for conservation. The high mortality rates for cloned animals are the largest obstacle as, depending on the species, up to 500 diverse, cloned individuals may be needed to build a healthy, wild population.
Cloning is also a rather inefficient method as often hundreds of embryos and pregnancies are needed to produce even a few clones. Related to this, cloning is also very expensive; cloning a cheetah for example would cost over $100,000.
However, researchers do argue that as cloning efforts become more successful, the cost of it will decrease, in particular for species that have already been cloned once. However, it remains that because of the cost, governments are unlikely to provide resources to universalise cloning of all endangered species.
“Cloning is expensive — only charismatic animals are likely to be cloned […] the cloning of endangered rays, caecilians, or vipers may have to wait until we have done the showier rare birds and mammals” wrote David Ehrenfeld in the journal Conservation Biology in 2006.
There is also worry that cloning directs attention away from the problems leading to extinction. However, conservation biologists argue that cloning is being used as a last resort as our planet continues to lose on average 150 species a day.
Whilst conventional methods such as habitat protection should still be the main option, some species can no longer benefit from these. “Tomorrow is too late, today is too late for many species”, Ed Louis, Frozen Ark trustee, founder of British gene bank.
Our planet continues to lose on average 150 species a day
Species in dire situations are those where only a few dozen of animals remain. In these cases, the species cannot be reintroduced to their natural habitat even it is now protected, as the limited genetic diversity of the species makes them prone to illness, damaging mutations, and inbreeding, making it difficult for them to flourish in the wild.
By bringing genes that would have otherwise died out back in the gene pool, cloning can effectively make endangered species resistant to these issues. There is also the case that efforts to protect some species more conventionally cannot be made.
For example, as long as the consumer continues to purchase products containing palm oil, the Amazon rainforest and its inhabitants continue to be threatened, despite efforts to protect them. Collecting DNA from these endangered species for cloning guarantees the preservation of their genetic heritage and the possibility to increase genetic diversity and stabilise a shrinking population in captivity even before their habitat is restored.
Many questions remain, however; should cloning resources be used for saving species on the brink of extinction or those that are already extinct? How can extinct species be reintroduced to a greatly changed 21st century habitat? Could reviving extinct species negatively impact existing species? What species should be prioritised? These questions show that there is still much elaboration and progress to be made before cloning becomes a mainstream conservation technique.
Although cloning endangered species could be a valuable method in slowing down the rate of biodiversity loss and protecting species from extinction, many researchers agree that currently cloning is not a feasible nor effective conservation method. However, once cloning becomes properly established, it will become a very powerful tool.
Image: PublicDomainImages, Pixabay
