SCIENTISTS have long pondered the concept of de-extinction, or reviving long-gone species that are hundreds of thousands of years old.
Now they say we’re closer than ever to bringing the woolly mammoth back.
Standing at the forefront of a breakthrough is Colossal Biosciences, a Texas-based company committed to “solving the colossal problem of extinction.”
The biotech firm has raised at least $225 million in its quest to revive three extinct species: the dodo, the Tasmanian tiger, and, of course, the woolly mammoth.
So why not let sleeping mammoths lie? On its website, Colossal insists de-extinction will “enrich biodiversity, replenish vital ecological roles and bolster ecosystem resilience.”
Given such lofty goals, scientists must consider every potential outcome, including the less-than-savory.
Woolly mammoths lived in the Arctic between 300,000 and 10,000 years ago, meaning much of their genetic makeup is lost to the annals of time.
Colossal aims to produce its first calves by 2028 – and they won’t be all mammoth.
Researchers plan to identify the genes that code for the woolly mammoth’s most iconic physical traits, like curved tusks and a domed skull.
They will insert these genes into the genome of the Asian elephant, a present-day relative with similar DNA.
Colossal’s plan shows how “de-extinction” is loosely defined. It often means creating a hybrid species using preserved DNA to replicate the most crucial genes.
Creating a genetically identical animal is tricky, and only possible in some circumstances.
If a species perished more recently, the availability of fresher and more complete DNA would make cloning easier.
The Pyrenean ibex, for instance, was declared extinct in 2000 when the last known specimen died.
Three years later, scientists used DNA from a skin sample to temporarily “unextinct” the species. However, the clone suffered a deformed lung and died shortly after being born.
The Pyrenean ibex and other cloned animals paint a cautionary tale, as birth defects cause them to rarely survive to adulthood.
Colossal has gotten its hands on more than 60 partial woolly mammoth genomes, which will be used to edit elephant genomes in the lab.
A genome is an organism’s entire genetic makeup. Once scientists have settled on a DNA sequence, they will implant a hybrid elephant-mammoth embryo into an Asian or African elephant.
If successful, the reintroduction of the woolly mammoth could have unforeseen consequences.
The enormous creatures lived during the Pleistocene epoch and acted as groundskeepers, tromping across the Arctic grasslands and suppressing tree and shrub growth.
They also filled the role of pollinators by spreading nutrients through their dung.
In the absence of the woolly mammoth, the landscape has yielded to a wet, mossy tundra susceptible to permafrost thaw.
Some scientists believe reintroducing giant herbivores to the Arctic could help restore the ecosystem and even minimize the impact of climate change.
At the same time, they are patently aware of the challenges.
A genetically similar population may be susceptible to the same illnesses or carry the same mutation, leading to their demise.
It is also worth considering the flip side: what if mammoths aren’t as beneficial to the environment as scientists hope?
The Arctic ecosystem and the animals that call it home have transformed dramatically since the woolly mammoth last appeared.
The creatures may not be suited to survive in the Arctic any longer, and without an ecological niche to fill, they may cause more harm than good.
Mammoths could contribute to global warming by eroding the permafrost during the warm season and releasing methane.
They could also reduce the carbon stored in woody plants, similar to elephants in African savannas.
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Despite the risks, the Colossal team continues to focus on the positives.
“For the first time in the history of humankind, we are in control of a science with the power to reverse and prevent biodiversity loss on a large scale,” the company website reads.
“We can heal a hurting planet. We can protect the species living on it. We can ethically decipher and protect genetic codes. And we can begin to turn the clock back to a time when Earth lived and breathed more cleanly and naturally.”
