Researchers from Lund University, Sweden, have found that multicellularity in green algae is not driven by inherent advantages, but rather arises as a by-product of strategies employed by single-celled organisms to mitigate environmental stress. This study, conducted in Swedish lakes, identifies specific environmental conditions that promote the evolution of multicellular forms, challenging the prevailing belief that multicellularity evolves for benefits like predator protection.
The researchers discovered that there are no significant costs or benefits associated with living in multicellular groups. Instead, cells produce various substances that help them survive and, in turn, prevent daughter cells from dispersing away from the parent cell. Through experimentation with different green algae species—some always single-celled, some that switch to multicellularity under certain conditions, and others that are always multicellular—the team explored how environmental factors influence these transitions.
The findings not only shed light on the evolutionary pathways that lead to multicellularity but also enhance our understanding of biological diversity and the survival mechanisms of species crucial to ecosystems. This research underscores the complexity of life’s evolution and highlights how specific environmental conditions can foster the development of multicellular organisms.
