As the Siberian tundra feels the heavy footsteps of woolly mammoths, the giant moa boldly traverses New Zealand’s forest floor, while Tasmania’s dog-like “tigers” silently stalk their prey under the dark of night.
This scenario does not represent a glimpse into ancient times nor is it a precursor to Steven Spielberg’s “Jurassic Park” set to release next year.
Instead, it reflects a possibility that biogeneticists believe could occur within our lifetimes: the revival of species that have long been driven to extinction, sometimes even millennia ago.
Next Thursday marks the 60th anniversary of Francis Crick and James Watson’s groundbreaking publication revealing the structure of DNA, the double-helix that underpins life.
Currently, some experts contend that with the knowledge gained from this discovery, the first extinct species might be resurrected within a matter of years.
Cloning could happen using genetic material extracted from preserved tissues, with the modified egg transferred into a related species.
Looking further ahead, other species could be brought back to life through sequences of their DNA that are artificially reconstituted.
“Reviving the gastric frog might take perhaps one to two years. In the case of the mammoth, it could be 20 to 30 years, or even sooner,” said Hendrik Poinar, an evolutionary geneticist at Canada’s McMaster University, regarding ongoing “de-extinction” initiatives.
In 2009, a team of researchers successfully cloned a bucardo, or Pyrenean Ibex, using DNA obtained from the last individual of this breed before it perished in 2000.
Although it was the first cloned creature born from an extinct subspecies, the outcome was not entirely positive; the newborn, carried by a domestic goat, died shortly after birth due to lung complications.
Just last month, a group at Australia’s University of New South Wales reported having cloned embryos of the gastric-brooding frog, a species that vanished in 1983, known for its unusual reproductive method of ingesting its eggs, nurturing them in its stomach, and later expelling the offspring.
Sadly, all the cloned embryos perished within days.
In Australia, teams are also striving to resurrect the Tasmanian tiger, utilizing DNA sourced from an ethanol-preserved pup of this marsupial predator which became extinct in the 1930s.
Meanwhile, in Japan, geneticists announced in 2011 their intention to use DNA from preserved specimens to bring back the woolly mammoth, which became extinct during the last Ice Age, within six years.
In the UK, scientists from Oxford University have gathered genetic data from museum specimens of the dodo, the flightless bird from the Indian Ocean islands, which was hunted to extinction by 1680.
Scientists are optimistic that reconstruction might be achievable for most animals with surviving DNA, potentially dating back 200,000 years — although this timeframe rules out a “Jurassic Park”-style revival of the dinosaurs.
For successful revivals, the DNA samples must be well-preserved, and advancements in cloning techniques are necessary to mitigate the risks of deformity, miscarriage, and early mortality, prevalent issues in contemporary animal cloning.
“As things stand now, I can understand why people envision the possibility of de-extinction,” Poinar remarked.
“I can see a future where, without legal barriers and once ethical considerations are sorted, regions in Siberia could be reinhabited by mammoths and cave lions.
“The key question, however, is: ‘Should we proceed with this?'”
Sociologist Carrie Friese from the London School of Economics expresses concern that ethical considerations have been overlooked in the excitement over potential resurrections.
“My worry is that the emphasis has shifted too heavily to: ‘Can we do this?’ instead of addressing how we will care for the living beings that result from these efforts,” she noted.
Many species went extinct precisely because their natural habitats were destroyed, Friese explains.
With a limited gene pool for adaptation in the wild, their cloned descendants might be fated to exist as mere exhibits in a museum. Additionally, they would lack authentic parental figures for socialization.them or instruct them on flying, foraging, or hunting.
“An animal is more than just its genome,” stated Friese. “How does a dodo acquire its knowledge of being a dodo?”
One of the advocates for species resurrection is Hank Greely, a bioethicist at Stanford University.
“The most compelling reason to pursue this is simply that it would be amazing,” he expressed. “It would be incredibly cool.”
However, he also warned against causing inappropriate and excessive pain and suffering in the name of scientific exploration.
Due to this and other considerations, cloning Neanderthals—most likely requiring a human surrogate—remains prohibited, even with the availability of high-quality genetic data.
Some argue that efforts toward de-extinction drain time and resources from the preservation of endangered species.
“Restoring extinct species holds limited conservation value and could even become a distraction,” mentioned Colman O Criodain from the conservation group WWF.
Nonetheless, there are potential advantages: gaining valuable insights from studying living relatives of extinct animals and possible environmental benefits.
Certain individuals believe that reintroducing mammoths to Siberia could transform the barren, mossy tundra back into the lush grasslands it once was thousands of years ago.
Additionally, technology might aid us in creating methods to increase genetic diversity for critically endangered species today.
Poinar emphasized that a transparent debate, rather than scientific secrecy or arrogance, is essential to navigate this ethical complex.
“What it really comes down to is engaging in a very sincere and straightforward conversation regarding the true reasons, along with the benefits and drawbacks,” he explained.
