In a discovery that sends shockwaves through our understanding of life’s history, a global team of scientists, including key researchers from the University of Campinas (Unicamp), has found the building blocks of mammalian life hidden within one of the planet’s most ancient creatures: the sea sponge. Using a combination of advanced chemical analysis and powerful supercomputer simulations, they have identified complex collagens, identical to those that form our own skin and bones, embedded in the fibrous skeleton of sponges. This finding doesn’t just rewrite textbooks; it opens a new frontier for developing revolutionary biomaterials. At the heart of this breakthrough lies the extraordinary power of Molecular Dynamics, a “virtual microscope” that allowed the Unicamp team to watch these ancient molecules in action.
An Evolutionary Riddle
The sea sponge is a creature of profound simplicity. Lacking a brain, muscles, or even true tissues, it represents one of the earliest branches on the animal tree of life, a living relic from nearly a billion years ago. The flexible skeleton of many sponges is made of a unique protein called spongin, long considered a primitive material for a primitive animal.
In the grand narrative of evolution, collagen was thought to be a different story entirely. It is the essential “glue” of complex animals. Our bodies are filled with specific types, like Collagen Type I, which gives our bones tensile strength, and Collagen Type III, which forms delicate networks in our organs. The scientific consensus was that these advanced collagens were a more recent innovation, developed by “higher” animals to build their sophisticated bodies. Finding them in a simple sponge would be like discovering a modern jet engine inside a perfectly preserved Model T Ford. It simply shouldn’t be there.
This is what makes the discovery published in the prestigious journal Nature Communications so staggering. An international team embarked on a deep dive into the molecular makeup of the common bath sponge, Spongia officinalis. What they found was biologically astounding: proteins that were, for all intents and purposes, identical to human Collagen Type I and Type III.
This discovery posed a critical question: Was this just a fluke, a non-functional evolutionary echo? Or were these collagen molecules actually providing strength to the sponge’s skeleton, just as they do in our own bodies? To answer this, experimentalists needed help. They needed to see the molecules in action, a feat impossible for any physical microscope. They turned to the computational team at Unicamp’s Center for Computing in Engineering & Sciences (CCES)—Professor Munir Skaf, Amadeus C. S. de Alcântara, and Clauber H. S. da Costa—to build a virtual time machine. Their tool of choice: Molecular Dynamics (MD) simulation.
The Virtual Microscope: Witnessing Ancient Molecules at Work
Molecular Dynamics is, in essence, a way to create a “virtual movie” of molecules. Instead of a camera, scientists use the fundamental laws of physics. Instead of actors, they have atoms. And instead of a script, they have “force fields”—a set of precise mathematical rules that describe how every atom pushes and pulls on every other atom.
The first task for the Unicamp/MIT computational team was to build their virtual world. Using the amino acid sequence of the newly discovered sponge collagen, they constructed a digital, atom-by-atom model of the protein chains. They then placed these chains into a “simulation box,” a cube of virtual space filled with millions of water molecules, mimicking the primordial ocean where these proteins first evolved.
With the stage set, the simulation began. The immense power of the Unicamp supercomputers was unleashed on a single task: to calculate the forces acting on every single atom at a given instant. Then, using Newton’s laws of motion, the computer would calculate where each atom would move in the next tiny fraction of a second—a femtosecond, which is a millionth of a billionth of a second. The process was then repeated millions of times, slowly and painstakingly generating a movie of how these molecules behave.
The scientists were looking for a process called self-assembly. In our bodies, three individual collagen chains first twist around each other to form a rigid, rope-like structure called a triple helix. These triple helices then line up side-by-side to form much larger fibrils, which give our tissues their remarkable strength. If the sponge collagen was truly functional, it should do the same thing.
As the researchers watched their simulation unfold, they witnessed something extraordinary. The individual collagen chains, initially placed randomly in the virtual water, began to find each other. Guided by the subtle dance of atomic forces, they intertwined, spontaneously forming the iconic triple helix structure. The simulation proved that the sponge collagen possessed the intrinsic, encoded information to build itself correctly, without any external guidance.
Next, the team simulated multiple triple helices together. Once again, self-assembly took over. The molecular ropes began to align and pack together into the ordered, staggered pattern of a mature collagen fibril. They had watched the birth of a sponge-collagen fibril from its constituent parts, confirming it followed the same fundamental architectural plan as our own.
But looking the part is one thing; acting the part is another. The final and most critical test was mechanical. The researchers used their simulations to perform a “virtual stress test.” They took their fully formed digital fibril, grabbed its ends, and pulled, measuring its resistance to stretching. This allowed them to calculate its stiffness and strength, key material properties. As the virtual fibril stretched, they could see exactly how the molecular structure responded to the force, how the protein chains slid past one another, and how the surrounding water molecules participated in the process.
The results were unequivocal. The collagen fibrils contributed significant mechanical strength and resilience to the overall structure. It wasn’t just an evolutionary artifact; it was a core, functional component of the sponge’s skeleton. Professor Munir Skaf, Director of the CCES, explains the significance: “MD simulations allow us to build a story, to connect the dots. We could confirm that this ancient protein doesn’t just share a name with our collagen; it shares a fundamental function written into its very atomic structure. This was the crucial evidence that elevated the discovery from a curiosity to a paradigm shift.”
A New Future Inspired by the Ancient Past
This discovery, validated by the powerful simulations at Unicamp, has profound implications for medicine and materials science. It effectively redraws the evolutionary map, showing that nature perfected the molecular blueprint for a key component of complex animal life far earlier than we ever imagined. This “collagen toolkit” wasn’t invented by mammals; it was inherited from a deep, common ancestor, a heritage we share with the humble sea sponge.
This newfound understanding opens up a treasure trove of possibilities.
First, in the field of biomedical engineering, there is a constant search for better materials for tissue repair—scaffolds for skin grafts, new ligaments, or structures to help regrow organs. Collagen used for these purposes is often sourced from cows or pigs, which carries a small risk of disease transmission and can cause immune reactions. Spongin, with its integrated, human-like collagen, offers a tantalizing alternative. It is a natural, biocompatible composite material, honed by nearly a billion years of evolution. The Unicamp team’s work provides the first blueprint for understanding and harnessing its mechanical properties to create a new generation of medical materials that could be safer and more effective.
Second, nature is the ultimate engineer, and the spongin-collagen composite is a masterclass in material design. It is lightweight, strong, flexible, and self-assembles in a wet environment. The detailed models created by the MD simulations can now serve as an inspiration for materials scientists to develop new synthetic polymers and composites with unique properties, potentially leading to everything from more durable textiles to new types of flexible electronics.
Finally, studying this ancient, successful form of collagen can give us new insights into our own diseases. Many conditions, from osteoarthritis to genetic disorders, are caused by defects in our body’s collagen. By studying a version of this protein that has been working perfectly for eons, we can better understand what goes wrong in our own bodies, potentially revealing new targets for therapeutic drugs.
In the end, the journey into the heart of the sponge’s skeleton has connected the distant evolutionary past with the cutting edge of modern science. It is a powerful reminder that incredible secrets still lie hidden in the natural world. Thanks to the collaborative spirit of international science and the power of computational tools like those at Unicamp, we are better equipped than ever to uncover them, turning the secrets of an ancient sponge into the solutions of the future.