The origins of multicellular life have long puzzled biologists, with the first known instance occurring around 2.5 billion years ago. A new study published in Nature Physics suggests that physical forces, such as those involved in cooperative feeding by a single-celled organism called Stentor, played a key role in the evolution of multicellular life.
Stentor is a trumpet-shaped cell that can grow up to 2 mm long and uses its cilia-lined mouth to suck in food particles from the water. When two or more Stentors form a colony, they can double their feeding efficiency by creating stronger vortexes that bring in more prey.
However, the benefits of forming a colony are not evenly distributed among individual cells. Weaker Stentors tend to gain more from teaming up with stronger partners than vice versa. This phenomenon is reminiscent of a game where two players switch between partners, ultimately resulting in all cells gaining stronger feeding flows.
The researchers propose that this “promiscuity” in the colony may have driven the evolution of multicellular life. By working together and switching partners to maximize their individual benefits, cells can increase their chances of survival and success.
While Stentor colonies are ephemeral and disband when resources become scarce, the scientists suggest that this model precedes other models of early multicellularity, which often involve the formation of clones or genetically identical cells.
The discovery highlights the importance of physical forces in shaping the evolution of complex life forms. By exploring the role of fluid dynamics in cooperative feeding, the researchers have provided a new perspective on the origins of multicellular life and may shed light on the mechanisms that govern this critical process.
Source: https://phys.org/news/2025-03-physical-evolution-multicellular-life-scientists.html