Biotech firm Colossal Biosciences did not actually bring dire wolves back from extinction when it engineered animals in 2025, according to a scientific argument published in Biology Letters.
Marine biologist Andrew Davinack and biochemist Charlotte Daniels from Wheaton College Massachusetts published the paper to challenge high-profile claims surrounding genetic recreation. In a Huberman Lab conversation, Dr. Beth Shapiro, chief scientific officer at Colossal Biosciences, outlines the mechanics of de-extinction, defends the dire wolf against gimmick accusations, and highlights how these identical methods might safeguard living organisms and even contribute to human genetics. What Colossal Biosciences accomplished involved sequencing genomes from fossil dire wolves, learning which genetic changes made them bigger, more robust and light coated, and engineering 20 edits into a gray wolf genome.
The researchers generated three animals—named Romulus, Remus and Khaleesi—by hand rearing them, preventing them from breeding using hormones, and skipping alterations known to provoke blindness or deafness in living wolves while applying safe variants found in light colored dogs.
The researchers contend that calling this achievement a de-extinction is a mistake and coined the term lineage-genome conflation to describe it. ScienceAlert reported that the authors emphasize how extinction represents the permanent termination of an evolutionary lineage rather than the mere disappearance of genetic information.
The argument rests on the premise that a species is much more than its DNA sequence. Genes and physical traits emerge from a long, continuous evolutionary history, and any gaps in that history break the connection entirely.
Species are historically continuous population-level lineages shaped by gene flow, mutation, drift, selection, demographic history and ecological interaction,
Andrew Davinack and Charlotte Daniels, researchers
The authors explain that a reconstructed genome represents at most a partial snapshot of an individual organism rather than a restored species.
Beyond genetics, the researchers point out major hurdles regarding populations and historical environments. A small group of engineered animals cannot recreate the genetic variation of a large historical population or the specific ecosystem it inhabited.
Dire wolves lived in a profoundly different world more than 10,000 years ago, devoid of the same climates, food sources, and predators found today. In Siberia’s Pleistocene Park, a diverse plant mosaic is maintained and soil temperature is kept low because large herbivores clear away surface snow.
Genomic reconstruction may recreate selected traits or produce ecological proxies, but it cannot recover extinct species as historically continuous evolutionary lineages,
write Davinack and Daniels in their published paper. They acknowledge that many scientists avoid using terms like de-extinction inaccurately, but they urge private companies and media outlets to exercise greater responsibility when reporting technological advances.
The researchers note that utilizing preserved cells or embryos offers a more promising route for true de-extinction because it solves several environmental hurdles and ensures greater biological continuity. Scientists previously attempted cell preservation techniques with the Pyrenean ibex back in 2003, which provided a stronger claim to de-extinction despite the animal failing to survive.
Precision in scientific terminology carries practical consequences for ongoing biotech initiatives. Lineage restoration, genetic recovery, phenotypic reconstruction, ecological substitution and restoration of historical communities are distinct objectives and require different criteria of success,
write the researchers. While they do not argue that genetic engineering companies lack merit, they maintain that the 2025 dire wolf project produced gray wolves with specific traits rather than a true resurrection of an extinct species.
