Context:
Colossal Biosciences, a U.S.-based biotechnology company, is making headlines for its ambitious attempt to resurrect extinct species using gene-editing technology. Led by Harvard geneticist George Church, the company’s flagship project involves reviving the woolly mammoth with the stated goal of combating climate change through ecosystem restoration in the Arctic tundra.
Key Scientific Developments
- De-extinction through Genomics:
- The company has extracted ancient mammoth DNA from fossils and used CRISPR-based gene editing to modify elephant DNA to express mammoth-like traits.
- The long-term goal is to create a mammoth-elephant hybrid embryo and use a surrogate elephant for gestation.
- Climate Justification:
- Advocates argue that woolly mammoths could help restore Pleistocene grasslands, which would reflect more sunlight, absorb less heat, and limit methane emissions from thawing permafrost.
- Siberian experiments using cold-resistant animals show partial success in rewilding efforts.
- Expansion to Other Species:
- Colossal has also attempted to revive the dire wolf, birthing three edited snow-white wolves. However, only 20 genes were altered, leading to criticism that the result is not an authentic revival but a genetically modified variant.
Ethical and Scientific Critique:
- Lack of Peer Review and Scientific Credibility:
- The dire wolf claims lack rigorous peer validation and are viewed skeptically by the broader scientific community.
- Critics argue that these are cosmetic changes, not true de-extinctions.
- Resource Allocation Concerns:
- Conservationists warn that investing millions in speculative, long-term projects diverts attention and funding from the urgent crisis of contemporary species extinction caused by deforestation, urbanization, and habitat destruction.
- Thousands of extant species face immediate threats, yet receive far less support.
- Call for Regulation:
- The article underscores the need for strict guidelines governing the use of gene-editing technologies for non-medical purposes.
- The case of He Jiankui—the Chinese scientist who controversially edited human embryos—is cited as a cautionary example of unregulated scientific ambition.
What Colossal Did: The Science Behind It
Species involved:
- Dire wolf (Aenocyon dirus): Extinct ~11,000 years ago
- Gray wolf (Canis lupus): Closest living relative
Key scientific steps:
- Ancient DNA analysis: From a 13,000-year-old tooth and a 72,000-year-old ear bone
- CRISPR-Cas9 gene editing: 14 targeted edits made to gray wolf DNA
- Embryo creation: Modified cells used to create embryos
- Surrogate mothers: 45 embryos implanted into two domestic dogs
- Successful births: Romulus and Remus (first), followed by Khaleesi
Result:
Pups are 99.5% gray wolf DNA, but display visual traits of dire wolves—white coats, large muscular bodies, stronger jaws.
While Colossal Biosciences’ work represents a leap in genome engineering and synthetic biology, its claims of aiding conservation through de-extinction are seen as scientifically weak and ethically questionable.
