Rare Phenomenon: Two Life Forms Merge into Singular Organism Once in a Billion Years

For the first time in over a billion years, two distinct life forms have merged into a single organism, a process known as primary endosymbiosis. This rare evolutionary event has occurred only twice in Earth’s history, leading to the emergence of complex life forms such as mitochondria and plants.

An international team of scientists observed this phenomenon between a species of ocean algae and a bacterium. This groundbreaking discovery sheds light on the origin of complex life and offers new insights into evolution.

Tyler Coale, a postdoctoral researcher at the University of California, Santa Cruz, led one of the studies that uncovered this merging of life forms. He explained, “The first time we think it happened, it gave rise to all complex life. Everything more complicated than a bacterial cell owes its existence to that event.”

In this recent observation, the algae engulfed the bacterium, providing it with nutrients, energy, and protection in exchange for certain functions it couldn’t perform independently, such as nitrogen fixation. Eventually, the algae incorporated the bacterium as an internal organ, crucial for its functioning.

Jonathan Zehr, another researcher involved in the study, likened this process to the formation of organelles like mitochondria and chloroplasts, which play essential roles within cells.

The discovery not only deepens our understanding of evolution but also has potential implications for agriculture. Coale remarked, “This system is a new perspective on nitrogen fixation, and it might provide clues into how such an organelle could be engineered into crop plants.”

The collaborative effort involved scientists from prestigious institutions worldwide, including the Massachusetts Institute of Technology (MIT), the University of Rhode Island, UC Santa Cruz, and institutions in Japan and Spain.