De-extinction and species-preservation company co-founded in 2021 by Ben Lamm and geneticist George ChurchPersonGeorge ChurchHarvard and MIT geneticist and genomics pioneer whose lab helped launch genome sequencing, CRISPR editing, and de-extinction, and who has founded dozens of biotech companies.Person →, targeting the woolly mammoth, thylacine, and dodo.
Facts
- Founded
- 2021
- Co-founders
- Ben Lamm and George Church
- Headquarters
- Dallas, Texas
- Focus
- De-extinction and gene editing
- Flagship projects
- Woolly mammoth, thylacine, dodo
- Valuation
- Around ten billion dollars (2025)
Overview
Colossal Biosciences is an American biotechnology company pursuing de-extinction, the creation of living animals engineered to resemble extinct species, alongside tools intended to help conserve endangered ones. Founded in 2021 by entrepreneur Ben Lamm and geneticist George ChurchPersonGeorge ChurchHarvard and MIT geneticist and genomics pioneer whose lab helped launch genome sequencing, CRISPR editing, and de-extinction, and who has founded dozens of biotech companies.Person → of Harvard Medical School, the company uses gene editing and reproductive technologies to reintroduce lost traits into the living relatives of vanished animals. Its flagship projects target the woolly mammoth, the thylacine or Tasmanian tiger, and the dodo. By 2025 Colossal had reached a valuation of roughly ten billion dollars, making it one of the most highly valued private biotechnology companies and, according to reporting, one of the first decacorns based in Texas. Church's laboratory had long explored editing elephant cells to carry mammoth traits, and the company raised a series of large financing rounds on the strength of investment from firms and high-profile individual backers.
How the approach works
Colossal does not claim to clone extinct animals from intact ancient DNA, which typically degrades beyond use. Instead its scientists sequence DNA recovered from remains, compare it with the genome of the closest living relative, and then use CRISPR and related base and prime editing tools to edit that relative's genome so it expresses traits associated with the extinct species. For the mammoth the reference relative is the Asian elephant, engineered toward cold-adapted traits such as dense hair and thick fat. The company also invests in reproductive science, including work on stem cell biology and artificial-womb technologies, to gestate edited embryos.
2025 announcements
Colossal drew global headlines in 2025 with two announcements. In March it unveiled the woolly mouse, ordinary mice engineered with several mammoth-associated genetic changes that gave them long, thick coats, presented as a proof of concept for making multiple coordinated edits. In April the company announced what it described as the return of the dire wolf, three pups named Romulus, Remus, and Khaleesi. The dire wolf claim prompted immediate debate. Colossal's own chief scientist, Beth Shapiro, clarified that the animals were gray wolves carrying roughly twenty gene edits selected to produce dire-wolf-like features, not exact copies of the extinct species, and acknowledged that it is not possible to recreate an animal identical to one that no longer exists. The episode sharpened a broader distinction between the company's headline framing and the underlying science.
Conservation debate
Colossal presents de-extinction as a driver of conservation, arguing that the genetic and reproductive tools it develops can also help protect living endangered species, and it has publicized work aimed at animals such as the northern white rhino and the red wolf. Critics counter that engineered proxies are not truly the extinct species, that reviving lost animals raises unresolved ecological and animal-welfare questions, and that the attention and money involved might be better spent preventing extinctions in the first place. Supporters respond that the technology platform has value regardless of whether a mammoth-like calf is ever born. As of the mid-2020s, the company's most ambitious goals, including a living mammoth-like calf, remained stated targets rather than accomplished results.