Context: Colossal Biosciences, a US-based bioscience company, claimed that it had revived dire wolves as the world’s first successfully de-extinct animal.
Relevance of the Topic: Prelims: Key facts related to Dire wolf and gene editing.
De-Extinction of Dire Wolf
- Scientists extracted and sequenced DNA from two ancient dire wolf specimens — a 13,000-year-old tooth and a 72,000-year-old ear bone. This analysis identified 20 key genetic differences between dire wolves and their closest living species, grey wolves.
- Using CRISPR technology, researchers edited the 14 genes in grey wolf DNA to incorporate 20 key genetic variants associated with dire wolf traits, such as larger size, broader heads and thicker fur.
- The genetic material was inserted into an egg cell from a domestic dog. Once the embryos were developed, they were implanted into surrogate dogs. Consequently, the genetically engineered pups were born (named Romulus, Remus, and Khaleesi).
- Controversy: While Colossal Biosciences referred to these animals as “de-extincted” dire wolves, experts argue that they are genetically modified grey wolves rather than true representations of the extinct species.
Dire Wolf
- Dire wolves were large canines that dominated southern Canada and the US before their extinction about 13,000 years ago.
- Dire wolves resemble the grey wolves sharing 99.5% of their DNA. However, dire wolves are not the ancestors of grey wolves. The two species diverged millions of years ago and evolved separately.
- Physical Appearance: Dire wolves are larger with white coats, more heavily built, thicker legs, broader heads and shoulders, and more pronounced snout. Dire wolves could be 3.5 feet tall, >6 feet in length, and weigh up to 68 kg.
- Dire wolves hunted horses, bison, and possibly mammoths. One of the possible reasons behind their extinction is the extinction of its prey species.
Gene Editing
- Gene editing is a scientific method where scientists modify DNA — the genetic code that determines how an organism looks, grows, and behaves. Think of DNA like a biological instruction manual made up of letters (A, T, C, G). With gene editing, scientists can add, delete, or replace parts of that manual to change how an organism develops.
- CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is the most popular gene-editing technology that allows precise modification of DNA sequences.