When we think about extinct animals, our curiosity often starts with what they looked like. We marvel at skeletons and illustrations, trying to picture them in motion. But what if we could go deeper? What if we could understand not just their form, but their function—how their bodies actually worked on a cellular level moments before they vanished forever?
This question is no longer just science fiction. The Tasmanian tiger, or thylacine, a unique marsupial predator, was hunted to extinction, with the last known individual dying in a zoo in 1936. For decades, it has been a silent symbol of what we have lost. Now, in a groundbreaking achievement, scientists have managed to retrieve and sequence RNA—the fragile, active counterpart to DNA—from a 130-year-old thylacine specimen that was stored at room temperature in a museum.
For the first time, scientists haven’t just read the dusty genetic encyclopedia of an extinct animal; they’ve read its mail—the urgent, fleeting messages that ran its body moments before it was lost to time. By reading these ancient molecular messages, researchers have opened a new window into the biology of an extinct species. Here are the five most surprising and impactful takeaways from this incredible study.
A Molecular Message in a Bottle, Uncorked at Room Temperature
Think of DNA as a massive library containing the complete genetic blueprint for an animal—every gene it possesses. RNA, on the other hand, is like a photocopied note sent from that library to the factory floor. It’s a temporary message that tells a cell which genes to turn on and use at a specific moment.
This discovery is so shocking because RNA is notoriously fragile and breaks down much faster than DNA. While a 2019 study showed that RNA could survive in specimens preserved in permafrost or even in old wolf skins, this was different. The fact that researchers could recover useful RNA from a thylacine that was simply dried and stored in a museum cabinet pushes the known limits of molecular survival. This work pioneers a new field called “paleotranscriptomics,” the study of ancient RNA.
But how could they be sure this wasn’t modern contamination? The answer was written in the RNA itself, in the form of chemical scars. Ancient molecules are expected to have a specific type of damage called deamination, and the thylacine’s RNA showed this exact pattern, providing the molecular fingerprint that proved it was the genuine, 130-year-old article.
Reading the Biological To-Do List of an Extinct Animal
Because RNA represents active genes, sequencing it is like reading a ghostly activity log from the animal’s tissues. It provides a snapshot of the thylacine’s biology in action, a feat impossible with DNA alone. The researchers found clear, tissue-specific signals that brought the animal back to life on a molecular level.
In a muscle sample taken from near the shoulder blade, the RNA showed strong activity from genes related to contraction and energy, including one for the huge protein titin. The profile perfectly matched that of slow muscle fibers. In the skin samples, the RNA was dominated by messages from keratin genes, responsible for building the tough, protective outer layer. In a fascinating forensic detail, they even found hemoglobin RNA—a clear sign of blood left in the tissue when the specimen was first prepared over a century ago.
A Cheat Sheet for the Thylacine’s Genetic Blueprint
Having the raw DNA sequence of an extinct animal is one thing, but making sense of it is another. This process, called “genome annotation,” involves identifying and labeling where genes start and end on the genetic map. It’s a complex puzzle that is often left with gaps and errors when relying only on DNA.
The recovered RNA provided a powerful cheat sheet. Because RNA molecules are copies of finished gene messages, they showed researchers exactly where certain genes were located, allowing them to fix errors and fill in gaps in the previously assembled thylacine genome. For example, they were able to pinpoint the location of ribosomal RNA genes that had been missing from earlier maps. This isn’t just academic housekeeping; a flawless genetic blueprint is the essential foundation for moonshot projects like de-extinction and for precisely pinpointing the unique genetic traits that made the thylacine a one-of-a-kind marsupial predator.
Uncovering an Ancient Viral Graveyard
In a surprising twist, the team also detected traces of RNA viruses within the thylacine’s tissues. The researchers urged caution—the signals were thin, and the risk of modern contamination is always a concern—but the possibility is exhilarating.
This finding suggests that the millions of specimens stored in museums around the world could serve as an untapped archive of viral history. Imagine being able to find the ancestors of modern pathogens, watching their evolution play out over a century, and potentially uncovering secrets to how viruses jump between species—all from specimens hiding in plain sight.
Finding the Thylacine’s Tiny Genetic Dimmers
The study went even deeper, looking at tiny molecules called microRNAs. These are short RNA strands that don’t build proteins but act as master regulators, fine-tuning how much protein a gene makes. They are like dimmer switches for genetic activity.
The researchers not only identified these regulators but also confirmed the existence of a specific microRNA form that is unique to the thylacine. This discovery demonstrates how gene regulation can differ even between closely related species and provides another layer of insight into the thylacine’s unique biology at the molecular level.
A New Window into the Past
This study does more than just tell us about the Tasmanian tiger. It fundamentally changes the science of ancient genetics, moving it out of the freezer and into the vast, dry collections of museums worldwide. For the first time, we have shown that a rich, dynamic record of an extinct animal’s life can be preserved not just in its DNA, but in the fleeting messages of its RNA.
Of course, it’s important to remember the study’s limitations. The findings are based on a single animal, so they can’t represent the entire species, and the recovered RNA fragments were short and uneven, making less active genes difficult to study. Even so, this breakthrough transforms museum specimens from static relics into active biological archives. With countless specimens resting in drawers and cabinets across the globe, what other lost worlds are just waiting for us to read their stories?
