The idea of bringing dinosaurs back to life, fueled by popular culture, sparks questions about its scientific possibility. While “de-extinction” is a real scientific field, the reality for dinosaurs is far more complex. Scientific understanding indicates that resurrecting dinosaurs is currently beyond possibility.
The Science of De-Extinction
De-extinction involves various scientific approaches to revive extinct species. One prominent method is cloning via somatic cell nuclear transfer (SCNT). This process requires obtaining an intact nucleus from an extinct animal’s cell and transferring it into a denucleated egg cell from a closely related living species.
After transfer, the egg is stimulated to develop into an embryo, then implanted into a surrogate mother from the related species. This method cloned Dolly the sheep in 1996. Other de-extinction methods include genome editing, inserting extinct species’ genes into a living relative’s DNA, or selective breeding to re-create ancestral traits. These techniques rely on high-quality genetic material and suitable living relatives.
The Obstacles to Dinosaur Resurrection
Bringing back dinosaurs faces immense scientific barriers, primarily due to their extinction 66 million years ago. This timescale far exceeds DNA preservation limits. DNA is a fragile molecule that degrades over time, with a half-life of approximately 521 years. After about 6.8 million years, all chemical bonds in DNA would have broken down, rendering it unreadable.
Fossilization typically replaces organic material with minerals, meaning DNA is not retained in most dinosaur remains. While some exceptionally preserved fossils show traces of proteins, they do not contain viable, intact DNA. Therefore, the fundamental blueprint for cloning a dinosaur is not available. Furthermore, finding a suitable surrogate mother would be impossible, as their closest living relatives (birds) are too genetically distant to carry such a pregnancy.
De-Extinction in Practice
While dinosaurs remain out of reach, scientists are pursuing de-extinction for more recently extinct species. These projects are feasible because their DNA is better preserved, and suitable living relatives exist as surrogates. For example, efforts are underway to bring back the woolly mammoth by editing the genes of its closest living relative, the Asian elephant. The goal is to create a cold-resistant elephant with mammoth traits, with some companies aiming for calves by 2028.
Another project focuses on the passenger pigeon, extinct in the early 20th century. Researchers plan to introduce its genes into band-tailed pigeons, their closest living relatives, to restore traits of the extinct bird. A significant, though short-lived, success occurred in 2003 with the Pyrenean ibex. Scientists used frozen cells from the last individual to create a clone, born via a domestic goat surrogate, demonstrating de-extinction’s potential. These projects highlight the necessity of recently preserved genetic material and closely related living species.