Science is taking a major step forward by exploring the possibility of bringing extinct species back to life. Iconic animals like the woolly mammoth, the dodo, and the Tasmanian tiger could soon resurface thanks to advances in genetics.
The woolly mammoth could soon resurface thanks to advances in genetics.
Illustration image Pixabay
The de-extinction process begins with the extraction of DNA samples from the extinct species. Sometimes, it involves the complete genome; other times, the genes of the extinct species are inserted into the genome of a living animal. Then, through nuclear transfer, this sequence is implanted into an egg of a closely related living species, from which the original DNA has been removed. The resulting animal is genetically similar to the extinct species.
Partial successes have already been achieved. In 2003, a subspecies of the Pyrenean ibex, the bucardo, was cloned, but the newborn died shortly after. In 2013, embryos of the Australian gastric-brooding frog were created, although none survived to the tadpole stage.
Recent progress suggests that de-extinction could become a reality within a decade. Among the candidates, the woolly mammoth, which disappeared about 4,000 years ago, could be resurrected thanks to well-preserved DNA in permafrost. An American company, Colossal Biosciences, claims to produce its first 'mammoth-elephants' by 2028.
The dodo, an iconic bird from Mauritius, is another candidate. Extinct in the 17th century due to European colonization, its DNA was sequenced in 2022. However, technical challenges, such as introducing genetic diversity, remain to be overcome.
The Tasmanian tiger, a carnivorous marsupial, is also on the list. Extinct in the 1930s, its DNA was sequenced in 2017. Scientists are working to overcome the obstacles to give birth to a baby thylacine.
The North American passenger pigeon is another candidate. Extinct in 1914, its DNA has been sequenced, but it is too fragmented for an exact resurrection. A company plans to introduce DNA fragments into modern pigeons to create birds resembling the extinct species.
The Tasmanian tiger, extinct in the 1930s, could be brought back to life.
Image Wikimedia
Finally, the aurochs, the wild ancestor of modern cattle, could be brought back to life through back-breeding, a method that does not require genetic engineering. Projects in Europe aim to recreate an animal resembling the aurochs by selecting cattle with ancestral traits.
How does de-extinction work?
De-extinction begins with the extraction of DNA from extinct species, often from well-preserved specimens. This DNA is then inserted into the genome of a closely related living species. Nuclear transfer allows the creation of an embryo genetically similar to the extinct species.
Technical challenges are numerous, including the fragmentation of ancient DNA and the need to create genetic diversity to avoid a population of clones. Scientists use techniques to overcome these obstacles.
Partial successes, such as the cloning of the bucardo in 2003, show that de-extinction is possible, although difficult. Recent advances in genetics offer hope for major breakthroughs in the coming years.
What are the ethical issues of de-extinction?
De-extinction raises important ethical questions. Bringing extinct species back to life could disrupt current ecosystems. Resurrected animals might not adapt to their new environment.
Moreover, resources devoted to de-extinction could be used to protect endangered species. Some critics argue that the money would be better spent on conserving existing species.
Finally, there are questions about the welfare of resurrected animals. These animals could suffer from health problems due to genetic abnormalities. Scientists must carefully weigh the pros and cons of de-extinction.