Microbial ancestor of complex life was more sophisticated than previously thought, studies suggest

Our single-celled ancestor lived in a world without plants, animals or oxygen-rich oceans. Yet, this seemingly simple microorganism took the first steps toward complex life. From this ancestor emerged all multicellular (complex) life as we know it today: from yeast to blue whales, collectively known as eukaryotes. These organisms are built from cells containing specialized structures, such as a nucleus and other specialized structures, each performing distinct functions.