Colossal Biosciences has achieved what many considered impossible just months ago: the successful birth of three dire wolves, marking the first time an extinct mammalian species has been brought back to life through genetic engineering. Now, the Dallas-based biotech company is expanding its de-extinction pipeline to include New Zealand’s giant moa, a 12-foot-tall flightless bird that vanished 600 years ago. The transition from recreating ancient mammals to reviving extinct birds presents dramatically different technical challenges that highlight the evolving sophistication of de-extinction science.
The dire wolf achievement, announced earlier this year, relied on ancient DNA extracted from a 13,000-year-old tooth and 72,000-year-old skull. Scientists used CRISPR gene-editing technology to make 20 precise genetic modifications to gray wolf cells—the highest number of deliberate genome edits in any animal to date. This breakthrough established Colossal’s “end-to-end de-extinction technology stack” and demonstrated that complex ancient traits could be resurrected in living creatures.
Mammalian Success: The Dire Wolf Blueprint
The dire wolf project succeeded through a carefully orchestrated process that began with genome reconstruction from fossil DNA. Researchers identified 14 important genes with 20 distinct genetic variants that give dire wolves their characteristic features, including larger body size, wider skull structure, thicker light-colored coats, and unique vocalizations.
The team engineered these traits by harvesting endothelial progenitor cells from gray wolf blood samples—a less invasive procedure than traditional tissue sampling. Using multiplex CRISPR editing, they modified cell nuclei to install dire wolf gene variants while solving potential health complications. For instance, certain coat-color genes that would produce the dire wolf’s signature white fur might cause deafness in gray wolves, so scientists added compensatory genetic changes to achieve the desired appearance without harmful side effects.
The modified cells were then used in somatic cell nuclear transfer, a cloning technique where edited nuclei replace the genetic material in donor egg cells. The reconstructed embryos were implanted into domestic dog surrogates, ultimately producing Romulus, Remus, and Khaleesi—now thriving at an undisclosed 2,000-acre preserve.
Avian Challenges: Why Birds Present Greater Complexity
Colossal’s announcement of the South Island giant moa project, developed in partnership with New Zealand’s Ngāi Tahu Research Centre, represents a significant technical escalation. While the company has extensive fossil remains, bone fragments, and even feathers to study from the relatively recent moa extinction, the developmental biology of birds creates unique obstacles.
Scott Edwards, a professor of organismic and evolutionary biology at Harvard University, explains that the techniques necessary for bird de-extinction differ substantially from mammalian approaches because birds develop within eggs rather than through live birth. This egg-based development makes the cloning process considerably more challenging, requiring different methodologies for embryonic manipulation and gestation.
Unlike mammalian cloning, which relies on surrogate mothers carrying embryos to term, avian de-extinction demands artificial egg technology and precise control over embryonic development outside the body. The moa project will need to navigate these complexities while working with ancient DNA that may be more degraded than the relatively well-preserved dire wolf specimens.
From Ancient DNA to Modern Innovation
The progression from dire wolves to moa demonstrates Colossal Biosciences’ expanding technical capabilities. The company’s approach to the giant moa involves sequencing genomes for all nine known moa species and studying related birds like emus to understand evolutionary relationships and identify key genetic differences.
Ben Lamm, Colossal’s co-founder and CEO, describes this partnership as “a new model where indigenous leadership guides scientific endeavors,” emphasizing how traditional ecological knowledge will shape the technological deployment. The company plans to pair its genetic engineering tools with conservation applications, making the technology open-source under Māori community direction.
Conservation Applications Beyond De-Extinction
Both projects highlight how de-extinction technologies serve broader conservation purposes. The techniques developed for dire wolves have already been applied to endangered species: Colossal has successfully cloned red wolves, the most critically endangered wolf species, using the non-invasive blood sampling methods pioneered for the dire wolf project.
Similarly, the company is working on genetic rescue projects for species like the pink pigeon, which suffers from severe genetic bottlenecks. By introducing greater genetic diversity into embryos through edited primordial germ cells, scientists aim to improve species health and viability—demonstrating how de-extinction innovations directly support existing conservation efforts.
The moa project extends this conservation model internationally, with plans for ecological restoration in New Zealand focused on rehabilitating potential moa habitats while supporting existing native species. The initiative includes developing ecotourism ventures and carbon credit models to create sustainable economic incentives for conservation work.
Technical Evolution and Future Implications
The transition from dire wolves to moa illustrates the rapid advancement of genetic engineering capabilities. Dr. George Church, Colossal’s co-founder and Harvard genetics professor, notes that the precision editing capabilities demonstrated in the dire wolf project represent “a capability that is growing exponentially.”
While mammalian de-extinction through surrogate pregnancies has now been proven feasible, avian projects require developing entirely new methodologies for egg-based development and embryonic manipulation. Success with the moa would establish protocols applicable to other extinct bird species, including Colossal’s ongoing dodo project.
The technical evolution from mammalian to avian de-extinction represents more than scientific advancement—it demonstrates how biotechnology can adapt to different biological systems while serving conservation goals. As Colossal continues expanding its species portfolio, each project builds upon previous innovations while addressing unique challenges that advance the entire field of genetic engineering and species preservation.