Recently, Colossal Biosciences, U.S. based company, announced the birth of three genetically modified wolf pups, claiming them as “functional copies” of the extinct dire wolf.
- The pups, named Romulus, Remus, and Khaleesi, were born through surrogacy by dog mothers.
About the Dire Wolf
- The dire wolf (Aenocyon dirus) was a large, powerful canine that lived in North America and went extinct approximately 13,000 years ago.
- It was larger than today’s grey wolves.
- They preyed on large mammals like horses, bison, and possibly mammoths.
| De-extinction refers to the process of reviving extinct species using advanced genetic technologies. It aims to restore lost biodiversity and repair ecosystems.
Approaches to De-extinction:
- Cloning: This method uses preserved cells of extinct animals to create genetically identical individuals, as seen in efforts to clone the Pyrenean ibex.
- Selective Breeding: By breeding living species that have similar traits to extinct ones, scientists aim to recreate animals resembling the original species, such as breeding back the aurochs.
- Genetic Engineering: Scientists edit the DNA of living relatives to include genes from extinct species, as in attempts to revive the woolly mammoth using Asian elephant DNA.
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Technologies Used in the De-Extinction Process
- Ancient DNA Recovery: Scientists accessed dire wolf specimens, including a 13,000-year-old tooth and a 72,000-year-old skull.
- DNA was extracted from the petrous (inner ear) bone, known for preserving genetic material well.
- Genome Sequencing:
- Researchers reconstructed two complete dire wolf genomes.
- They compared these to other canids like grey wolves, coyotes, jackals, and dholes.
- It was confirmed that grey wolves share 99.5% of their DNA with dire wolves.
- Gene Editing: Scientists introduced 20 targeted genetic edits to the grey wolf genome.
- 14 genes were specifically modified to reproduce key dire wolf traits such as:
- Light-colored coat
- Coat length and pattern
- Increased body size
- Stronger musculature
- Embryo Implantation: Fertilized, gene-edited eggs were implanted into surrogate dog mothers which successfully led to the birth of three genetically modified wolf pups.
Are They Truly Dire Wolves?
- Despite genetic editing, the new wolves are not identical to the original dire wolves.
- According to a 2021 Nature study, dire wolves and grey wolves diverged around 6 million years ago, making them distant relatives despite appearances.
- Colossal is applying the morphological species concept, meaning that if an animal looks like a dire wolf, it can be classified as one.
- However, millions of base-pair differences still exist between the two species.
Significance of the De-Extinction
- Scientific Achievement: This marks the first reported attempt to bring back an extinct animal species through genome engineering.
- Ecological Impact: If successful, dire wolves could play a role in restoring lost ecological functions.
- Technological Advancement: Showcases advances in genome sequencing, gene editing, and ancient DNA recovery.
Current Limitations
- The pups do not possess natural social behaviors, as they were raised without parents or packs.
- They are not allowed to breed, and Colossal plans to create only a few more individuals.
- Thus, a self-sustaining dire wolf population has not yet been achieved.
- It also raises debates about species classification, animal welfare, and the risks of reintroducing engineered species.
9 Apr 2025
