Some time ago, the story of the popular movie "Jurassic World" was set to revive the extinct dinosaurs through gene editing. On August 16, scientists released a project similar to this one, which caused a lot of heated discussion.
The aim of this project is to revive the 1936 extinct carnivore "thylacine" through gene editing. It is then released into the wild on Tasmania and mainland Australia to restore lost ecosystems.
The plan to resurrect extinct thylacines at the hands of humans seems very romantic. But the successfully resurrected thylacine has "difficulty fully reproducing genetically," and experts fear that new hybrids will emerge like the extinct thylacine.
thylacine
What is an extinct thylacine?
The thylacine, scientifically known as Thylacinus cynocephalus, is not actually a wolf, but belongs to the same marsupials as kangaroos. Until the 20th century, they all lived on the Australian island of Tasmania. Because of the tiger-like stripes on their backs, they are also known as "Tasmanian Tigers".
Thylacines can reach 100 to 130 cm in length, and they like to lie diurnal and nocturnal, preying on small kangaroos such as wallabies with sharp teeth. The thylacine is at the top of the ecological pyramid of the marsupial world and can be compared to the "wolf" of other regions.
Thylacines once inhabited mainland Australia and New Guinea extensively, but since 30,000 years ago, modern humans have landed on the Australian island and brought with them dogs from Eurasia, which gradually evolved into the Australian wild dog (Canis lupus dingo), which has dealt a blow to the ecological environment of the thylacine. Losing the race to survive, the thylacine gradually disappeared into mainland Australia and instead moved to tasmania, a remote corner.
Although the thylacine survived on the island of Tasmania without dingoes, after the 19th century, with the influx of European immigrants, the thylacine that fed on livestock was seen as a thorn in the side of new Australian settlers. European immigrants to the Australian continent began a vigorous campaign to expel thylacines, and the life of thylacines was further compressed.
In 1933, the world's last thylacines were captured. One of them was named "Benjamin", who was housed at Beaumaris Zoo in Tasmania and died on 7 September 1936. Benjamin's death meant that the species of thylacine had completely disappeared from human vision, and humans have been searching for traces of wild thylacines since then, but they have not been found until 1986, when the official declaration of the complete extinction of the thylacine was issued.
Thylacine head
Will the long-extinct thylacine be resurrected?
The thylacine resurrection is a joint project of the AMERICAN venture capital firm Colossal Biosciences and the University of Melbourne in Australia. Colossal was founded in September 2021 to revive furry mammoths, and the thylacine is the company's second extinct animal resurrection project.
According to Colossal's official website, Dr Andrew Paske of the University of Melbourne, who participated in the project, extracted DNA from specimens preserved in the Victoria Museum in Australia after 2018 to reveal the genome sequence of the thylacine. Based on this, the team edited the genes of the closest marsupial cats to artificially resurrect the thylacine.
Dr Paske said: "With this technology, our ultimate goal is to release extinct species into the wild, and they play an indispensable role in the ecosystem. We hope to see the thylacine again on the tasmanian steppes one day. ”
Colossal's thylacine resurrection plan
The resurrected thylacine is not a thylacine anymore?
Although it is a dream project to resurrect extinct animals with the power of science, some experts have raised concerns about the resurrection project of the thylacine.
One view is that it is very difficult to fully resolve the genome sequence of the thylacine from ancient specimens, so the birth of thylacine and marsupial genes are hybrid animals. The hybrid is said to have health problems and may not survive without human help.
Tom Gilbert, a professor of evolutionary biology at the University of Copenhagen, answered in an email in an interview with CNN.
"The likelihood of obtaining the complete genome sequence of an extinct species is low, so we cannot perfectly reproduce the genome that has been lost." There are always some parts that cannot be changed. Therefore, the result may be hybridization (with extant species). ”
Will mammoths be resurrected in the future?
Local researchers in Australia have also raised concerns. Corey Bradshaw, a professor of earth ecology at Flinders University, questioned "Should we release the thylacine back into the wild?" In response to a question posed by a researcher at the University of Western Australia, he explicitly said "NO". "It's hard to breed a genetically diverse population, and we can't ensure the area where the thylacine lives," he said. ”
"To be able to survive in the wild, thousands of individuals with genetic diversity are needed. It is impossible for us to reproduce adequate samples of individuals who are able to survive in the wild and have sustained genetic diversity. ”
"As large predators, thylacines need a vast habitat area in order to collect food, establish territory, and raise offspring. Even if the problem of genetic diversity is solved, society will not allow large populations to be established. Consider that dingoes in much of Australia are now persecuted by humans. ”
Whether the resurrected thylacine can adapt to modern society, and what kind of extinct animal resurrection plan Colossal will bring us in the future, let's wait and see.