The Physics of Cold Water May Have Jump Started Complex Life

Frigid conditions during the "Snowball Earth" periods, when the planet was largely covered in ice, may have facilitated the evolution of complex multicellular life. Research led by Carl Simpson at the University of Colorado, Boulder, suggests that as seawater cools, it becomes more viscous, making it difficult for single-celled organisms to navigate and feed. This increased viscosity could have pressured these organisms to adapt by forming larger groups, potentially leading to multicellularity.

Simpson's team conducted experiments with green algae, observing that as the viscosity of their environment increased, the algae began to form larger, coordinated groups. These clusters were able to swim collectively, maintaining their feeding efficiency despite the challenging conditions. Remarkably, even after returning to a less viscous environment, the algae continued to stick together for many generations, indicating a possible evolutionary shift.

The findings provide a new perspective on the emergence of multicellular life, emphasizing the role of physical conditions in shaping biological evolution. While the research is still in the early stages and has not yet undergone peer review, it highlights the potential impact of environmental factors on the development of complex life forms. This work adds to the ongoing exploration of how ancient climatic events influenced the trajectory of life on Earth, suggesting that the harsh conditions of Snowball Earth may have inadvertently spurred significant evolutionary advancements.