Ancient Tooth Proteins Rewrite the Rhino Family Tree—Are Dinosaurs Next?
Molecules from the 20-million-year-old teeth of a rhino relative are among the oldest ever sequenced, opening tantalizing possibilities to scientists. Researchers have described proteins that they say are among the most ancient ever sequenced. Two teams, which analyzed molecules from extinct relatives of rhinos and other large mammals, have pushed back the genetic fossil record to more than 20 million years ago.
The studies, published in Nature, suggest that proteins survive better than researchers thought. This raises the possibility of gleaning molecular insights about evolutionary relationships, biological sex, and diet from even older animals — maybe even dinosaurs. Matthew Collins, a palaeoproteomics specialist at the University of Cambridge, UK, and the University of Copenhagen, believes that this discovery opens up a whole new set of questions that palaeontologists never thought they could get near.
Preserved in teeth
The ability to obtain DNA from remains that are thousands of years old has revolutionized biology, revealing previously unknown human groups such as the Denisovans and rewriting the population history of humans and other animals. Proteins, biological building blocks encoded by the genome, are hardier than DNA and can push researchers’ abilities to use molecules to understand ancient species deeper into the past. In one of the latest studies, a team extracted proteins from the enamel of a 23-million-year-old relative of rhinoceroses, revealing new insights into the evolution of rhinos.
Next step, dinosaurs
Proteins degrade in the heat, making it challenging to extract ancient proteins from fossils in hot environments. However, a second team sequenced enamel proteins from fossils as old as 18 million years found in the Turkana Basin in Kenya. The researchers hope to obtain ancient proteins from early hominin remains found in Turkana Basin and even from dinosaurs, although extracting proteins from dinosaur teeth presents a significant challenge due to their thin enamel.
The studies are a major technical achievement that opens up new possibilities for understanding the history of life. As researchers continue to explore ancient proteins, there is hope that meaningful insights into evolutionary relationships, biological sex, and dietary habits can be gleaned. The potential applications of ancient proteins are vast, offering a wealth of information about past species.
In conclusion, the sequencing of ancient tooth proteins has provided valuable insights into the evolutionary history of rhinos and other large mammals. The ability to extract proteins from fossils dating back millions of years opens up new avenues for research and discovery. As scientists continue to push the boundaries of palaeoproteomics, the potential for uncovering even more ancient secrets remains limitless.
