What Unites Complex Multicellular Life?

Complex multicellular life, seen in animals, plants, and fungi, didn’t just evolve once but several times over. Imagine certain genes mimicking cell glue to start the process. Then, signals between these cells kickstarted some serious communication. Add to that expanding families of genes shaping cell and tissue identity. Scientists often use the number of cell types as a measure of biological complexity. While individual gene families grow with complexity in different life forms, why and how these complex creatures evolved remains a mystery. Researchers used a special strategy to compare genomes of 81 diverse species, including all complex multicellular ones. They found common themes like stuff making up the extracellular matrix, communication tools, and development paths. Unexpectedly, wound response, immune systems, cell movement, and rhythm response also cropped up. These findings hint at similar selective pressures guiding these life forms’ evolution. It’s like they took different roads but ended up in the same place. Pretty cool, huh?