New Evidence For Evolutionary Link Between Single-celled And Multi-celled Organisms

                        What do humans and single-celled choanoflagellates have in common?

More than you’d think. New research into the choanoflagellate genome shows these ancient organisms have similar levels of proteins that cells in more complex organisms, including humans, use to communicate with each other. These findings help confirm choanoflagellates’ role as an evolutionary link between single-celled and multi-celled organisms. The researchers (from the University of California, San Francisco and the European Molecular Biology Laboratory in Heidelberg, Germany), also contend that these insights into the organism’s genome mean that the proteins used to help cells communicate have other roles.  So much for Behes “Irreducible Complexity”

Choanoflagellates, or at least their ancestors, have long been suspected as being the bridge between microorganisms with only one cell and metazoan, or multi-cellular organisms.By analyzing the choanoflagellate genome, the researchers discovered another similarity between choanoflagellates and most metazoans–their genetic code caries the markers of three types of molecules that cells use to achieve phospho-tyrosine signaling proteins.The researchers conclude that the presence of the full three-component signaling system provides new insights into how multi- cell organisms evolved.