Alumnus Works to Genetically Engineer Extinct Life
By: Jeff Joiner | July 8, 2025
There’s been lots of news reports in recent years about a Texas company planning to use genetic engineering to “de-extinct” animal species no longer found on Earth. Colossal Biosciences, based in Dallas, is that company working to bring back animals like the woolly mammoth, the dire wolf and the dodo bird using bioengineering technologies. And Ben Collerton MS’23, a senior research associate and a graduate of The University of Texas at Dallas, is one of the company’s scientists helping make what seems like science fiction a reality.
“Working at the forefront of science and trying to expand our current technological limitations, I feel, is every scientist’s dream,” said Collerton, who earned a master’s degree in biomedical engineering from UT Dallas’ Erik Jonsson School of Engineering and Computer Science. “The technologies we are working to develop have the potential to have such far-reaching implications outside of just our current projects.”
Born in England and raised in New Zealand, Collerton came to the United States for college, earning a bachelor’s degree in biology from Texas State University before enrolling at UT Dallas for graduate school. He said he always wanted a career in some aspect of medicine, either in research, developing medical devices or becoming a doctor. He felt a graduate degree in bioengineering would prepare him for any number of careers in medicine.
While attending classes in his bioengineering focus, Collerton took a course on gene editing and the genetics tool CRISPR taught by Dr. Leonidas Bleris. After early interactions, Bleris invited Collerton to join his genetic engineering laboratory.
“Dr. Bleris is an amazing mentor and principal investigator,” Collerton said. “It is unlikely my path would have led to Colossal without Dr. Bleris opening the opportunity for me to work in his lab. His mentorship and the teaching of his lab members gave me the experiences and skills that led me to my Colossal internship and the career I have now.”
While working as an intern for Colossal, Collerton worked on projects including the generation of mouse models for specific genetic traits of interest to scientists working with Colossal species. He designed, constructed and tested genetic editing tools to make changes in mouse DNA required for cell line generation and also worked on Colossal’s project to de-extinct the dire wolf.
Founded in 2021, Colossal Biosciences is using biotechnology to bring species back from extinction, beginning with its best-known project, the woolly mammoth. The company hopes to genetically engineer living animals to restore lost phenotypes to the avian lineage to de-extinct the dodo and to ultimately release it into the wild.
The company has just announced a fifth extinct species that it plans to recover. Colossal said it is working with a research center in New Zealand to bring the South Island giant moa back from extinction, a huge flightless bird that reached more than 11 feet in height. The work, like that for the dodo, will be done by the company’s avian team, which will involve Collerton, a native of New Zealand
Colossal is also seeking to make it possible to clone certain endangered species of animals to save them before they’re lost to extinction and thus, in the long term, improve the Earth’s biodiversity.
“Behind the headline-grabbing de-extinction projects, every technology we work with to de-extinct a species can be directly applied to endangered species conservation, to preserve existing ecosystems, as well as restore past ones,” Collerton said.
Collerton joined Colossal’s avian genomics team in 2023, focused on de-extincting the dodo, a large flightless bird, which at one time could only be found on Mauritius Island in the Indian Ocean. On the island, first visited by Dutch explorers in 1598, the bird became prized by settlers for its meat, while non-native animals introduced by humans, like rats, devoured the bird’s eggs. By the late 1600s, barely 100 years after being found, the dodo was extinct.
“The dodo is commonly referred to as the first symbol of direct, human-caused extinction,” Collerton said. “This makes it a perfect candidate to be the first avian species to be de-extincted, with the technologies we develop laying the foundation to expand workflows to other endangered and extinct avian species.”
Colossal scientists were able to sequence the extracted DNA of the dodo from 500-year-old skeletal remains of a bird in a museum. With a complete genetic blueprint in hand, the avian team at Colossal, including Collerton, have set out to bring the species back from oblivion. The team is working to modify the DNA of the Nicobar pigeon, the closest living relative genetically to the dodo, to eventually make it possible to produce a dodo from a genetically engineered pigeon.
“With no living tissue existing from extinct species, we have to rely on editing the closest relative species in order to reverse the divergence that has occurred,” Collerton said.
As a genome engineer, Collerton and his fellow scientists use genetic editing tools like CRISPR-Cas9, only developed in the last decade, to make changes to phenotypes, or genetic characteristics, of a species’ DNA.
“You can essentially think of what we do as using natural versions of scissors and tape to change, rearrange or replace sections of a rope,” Collerton said. “Unique tools give us the ability to cut, paste or exchange DNA in precise, predictable ways, which ultimately gives us the ability to change and reprogram the building blocks of life.”
Just as it is with other species it’s focusing on, the genetic engineering of a dodo bird is a slow, meticulous process that will ultimately take years of work before success can be realized, work that requires the development of new technological processes required to make advances possible.
“I think the most complicated side of being a genome engineer is theorizing the solutions to complex problems and conceptualizing the potential avenues for necessary technological development,” Collerton said. “The hands-on lab work becomes easy with practice, but the abstract problem solving and discussions can be both equally fun and frustrating.”