A single, billion-year-old mutation helped multicellular animals evolve

[Dexter]

http://sciencelife.uchospitals.edu/2016/01/07/a-single-billion-year-old-mutation-helped-multicellular-animals-evolve/

In the history of life on Earth, few events were as significant as the evolution of multicellular animals from single-celled ancestors. This was no simple feat. To successfully function as a unified organism, every cell must play a specialized role and be in constant communication with other cells. If there are failures in cooperation, outcomes include cancer, developmental abnormalities or death. The complex interactions necessary for multicellularity are accomplished through intricate and coordinated molecular signaling. But almost nothing is known about how these molecular functions first evolved. It turns out, for one specific function at least, it most likely came down to dumb luck.

Taking a deep look into the distant, distant past, Joe Thornton, PhD, professor of ecology and evolution, and his colleagues focused on one particular protein that plays a key role in the formation of organized tissues in animals. Through “molecular time travel” experiments, they not only deciphered the sequence of the ancestral gene for this protein, they resurrected it in the laboratory to study how it functioned roughly one billion years ago. They found a single chance mutation was enough to cause the ancestor of the protein to evolve an entirely new function–one that became essential for multicellular organization.