Organelles without membranes are found in all types of cells and typically contain RNA and protein. RNA and protein are the constituents of ribosomes, one of the most ancient cellular structures. It is reasonable to propose that organelles without membranes preceded protocells and other membrane-bound structures at the origins of life. Such membraneless organelles would be well sheltered in the spaces between mica sheets, which have many advantages as a site for the origins of life.
Keywords: Muscovite mica; RNPs; mechanical energy; membrane-less organelles; membraneless organelles; origin of life; origins of life; ribonucleoprotein particles; ribosomes.