Plants and Animals

The Scientist’s Guide to Bringing Back the Extinct Tasmanian tiger

The Scientist’s Guide to Bringing Back the Extinct Tasmanian tiger

Benjamin, the last verified Tasmanian tiger, or thylacine, died in captivity in Hobart’s Beaumaris Zoo on September 7, 1936. These extinct stripey carnivorous marsupials may now be given a second chance. A $3.6 million grant has been made to scientists at the University of Melbourne in Australia for the construction of the Thylacine Integrated Genetic Restoration Research (TIGRR) Lab. Thylacines originally roamed the Australian continent some 3,000 years ago, but they became extinct owing to human hunting and dingo competition. Fortunately, the Tasmanian population grew isolated. This shielded them until they were falsely called “sheep killers” by early European settlers, and the government levied a £1 bounty per animal. As a result, they became extinct.

One of the most persuasive examples for de-extinction is this direct human-caused extinction. Other reasons include its importance as an apex predator in ecosystem stabilization — Tasmania’s ecology has stayed unaltered, allowing the thylacines to be reintroduced and reclaim their niche. A project of this scope will also generate crucial technologies and resources that will aid in the preservation and conservation of currently endangered marsupial species.

The genetic variety of any thriving group is one concern that may develop. Previous research has shown that the population had minimal genetic variety before to extinction, but sequencing numerous individuals may assist to restore genetic diversity in future generations. Furthermore, there have been earlier occurrences of severe bottlenecks that had little effect on repopulation. The Arabian oryx, for example, became extinct in the wild in the 1970s. The species has grown from nine individuals in captivity to over 6,000 in the wild, including 1,000 in the wild. So, how will these creatures be resurrected? Knowledge is power in this scenario.

Professor Andrew Pask led a team that published the first genome sequencing of a thylacine in 2018, utilizing DNA from a pouch young specimen at Melbourne Museum that had been preserved in alcohol for the last 100 years. The genome’s draft assembly was previously incomplete. New chromosome-scale genomes for the thylacine are now possible because to advancements in DNA assembly and an avalanche of high-quality reference genomes from closely related living species. The team is now working to refine the genome by sequencing many more specimens in order to discover species variation and compare it to the closely related dunnart marsupial — a mouse-sized mammal with large inky black eyes.

The amount and scope of modifications necessary to make a thylacine-like marsupial cell will be determined by this comparison. This massive computational endeavor will also aid in the biobanking of all vulnerable or endangered marsupial species. After gathering all of this data, the “Jurassic Park-style” experiments will commence. Living stem cells will be used to create an embryo by fusing a “thylacine” cell with an empty dunnart egg in assisted reproductive technologies (ART). The egg will subsequently be implanted into the uterus of the host mother.

The dunnart and the thylacine are different sizes, but happily, marsupials give birth to small young regardless of adult size, and the newborns usually finish their development in the pouch while drinking milk from the mother. When the thylacine infant is born, it will be separated from its mother and raised by a marsupial. Overall, this sort of production is likely to be panned, and the audience may associate it with a well-known film franchise. “When people say, ‘didn’t we learn anything from Jurassic Park?’ — Well, it’s very different bringing back a velociraptor to a thylacine,” Pask told the Washington Post.