On March 4, 2025 Colossal Biosciences announced that they had successfully implanted several genes from wooly mammoths into mice. Just over a month later, on April 7, Colossal announced that they had successfully created three dire wolf pups. All of these science fi advancements have left many with questions over the ethics and purpose of this work.
Colossal Biosciences is a biotechnology company based in Texas that was founded in 2021 by Ben Lamm and George Church. Colossal is focused on gene editing and de-extinction. They aim to map the DNA of close descendants of the extinct species and use this to identify the differences in the genes that make the extinct species unique. Then, they insert genes that code for those differences into cells that are extracted from the close relative. Afterwards, these cells are inserted into a surrogate mother and grow into a baby with the traits of the extinct species.
One of Colossal’s big goals is to have a baby mammoth on the ground by 2028. Due to the long gestation period, this means that the edited cells must be ready in less than 20 months. The first step to obtaining the cells needed to produce a calf is testing the gene edits. Colossal did this testing on the common mouse, which produced an adorable mouse known as a wooly mouse. These mice exhibit the long, golden fur, curly whiskers and a high fat metabolism of the mammoths that their DNA was modeled after.
Then, a little more than a month later, Colossal made a second shocking announcement: they had successfully created three dire wolf pups, named Romulus, Remeus and Khaleesi. These pups are currently living in an undisclosed location in the US, where they are under constant observation by many teams of scientists. This is the first example of what de-extinction may look like in the future. The process developed while bringing these pups to life is a much less invasive process than current cloning techniques, only requiring a blood draw as opposed to a highly invasive tissue sampling process.
All of this excitement has raised questions about the ethics of de-extinction. In a paper published by Cambridge University in 2023, the authors state “De-extinction is a conceptually and ethically challenging topic.” Some speculate that by reintroducing species that have been extinct for thousands of years we will be disturbing the current ecosystem and damaging food chains. Others argue that restoring animals that were driven to extinction by human actions, such as the dodo bird, should be reintroduced as a way to right past wrongs. Conservation scientists have a different approach: using the technology and information learned from the dire wolf and wooly mammoth, they can assist endangered populations of animals like red wolves and African forest elephants.
Additionally, scientists are questioning if these pups even count as dire wolves. While these living wolves share many of the same visual traits, like larger size and a white coat, many wonder if their genes are actually similar to their dire wolf ancestors.