Colossal Biosciences was started by Harvard geneticist George Church and technology entrepreneur Ben Lamm in September 2021 with $15 million in seed funding. The company raised another $60 million six months after launching despite doubts over the feasibility of resurrecting extinct species. Winklevoss Capital Management, motivational speaker Tony Robbins and Paris Hilton are among its investors.
Executives with Colossal say that by bringing back the thylacine, which was once widespread across mainland Australia and the islands of Tasmania and New Guinea, they can aid in efforts to re-balance Australian ecosystems that have suffered decades of sustained biodiversity loss.
The Tasmanian tiger was unique among marsupials with its iconic wolf-like appearance and diet of fresh meat. It was a quiet animal with thick black stripes on its body and, fully grown, measured about 6 feet from its nose tip to the tip of its tail. Thylacines were hunted to extinction by European settlers who thought of them as a threat to Tasmania’s sheep industry.
Colossal plans to take cells from the thylacine’s closest living relatives, like the dunnart, and genetically engineer them with thylacine DNA.
“You’re actually putting all of those genomic changes into that living cell, and then in the end, you are left with a cell that is a thylacine cell, and you can turn that cell then back into a whole living animal,” said Andrew Pask, an evolutionary biologist who is leading Colossal’s efforts to revive the animal. Similarly, Colossal would combine genetic material from Asian elephants with frozen woolly mammoth DNA to bring back a version of the latter species.
Not all experts are convinced by Colossal’s plans. Critics have called such experiments a distraction and say if they succeed their effects on the climate and ecosystems would be unpredictable.
Thomas Gilbert, a paleo-geneticist at the University of Copenhagen in Denmark, tested the possibility of resurrecting the Christmas Island or Maclear’s rat. Gilbert’s team had well-preserved DNA samples and abundant reference data from the animal’s cousin, the Norway rat. Yet even with all that information, he says, the researchers were unable to sequence the remaining 5% of the Maclear’s rat’s genome — leaving out important attributes like immunity and smell.
“If you have a million [genetic] differences between an elephant and a mammoth, you can’t necessarily change any one of those without there being a problem,” Gilbert said in an interview. “If I take a … Honda car, and if you try and put tractor tires on it or truck tires, it’s not gonna work, right?”
But Michael Archer, a paleontologist at the University of New South Wales in Sydney who does not have a relationship with Colossal Biosciences, says that efforts aimed at de-extinction are fundamentally necessary.
“It may well be enormously challenging and certainly a lot of work, but we can be certain of one thing — extinct animals will definitely stay extinct if we don’t try these things,” he said. “Some projects are moving forward quickly; others will take more time. In principle there is no fundamental reason why de-extinction should not be possible now or in the near future.”
Colossal’s most recent round of funding drew investment from entertainment world figures like Thomas Tull, former chief executive officer of Legendary Entertainment, and the Hemsworth family.
“The Tassie Tiger’s extinction had a devastating effect on our ecosystem and we are thrilled to support the revolutionary conservation efforts that are being made by Dr. Pask and the entire Colossal team,” actor Chris Hemsworth said in a statement.
–With assistance from Josh Saul.
To contact the author of this story:
Kevin Simauchi in New York at firstname.lastname@example.org
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