www.quantamagazine.org/scientists-debate-the-origin-of-cell-types-in-the-first-animals-20190717/
"For well over a century, it has been widely assumed that the ancestors from which the first animal evolved were simple blobs of identical cells. [...] The recent work paints a picture of ancestral single-celled organisms that were already amazingly complex. They possessed the plasticity and versatility to slip back and forth between several states — to differentiate as today’s stem cells do and then dedifferentiate back to a less specialized form. The research implies that mechanisms of cellular differentiation predated the gradual rise of multicellular animals."
"For well over a century, it has been widely assumed that the ancestors from which the first animal evolved were simple blobs of identical cells. [...] The recent work paints a picture of ancestral single-celled organisms that were already amazingly complex. They possessed the plasticity and versatility to slip back and forth between several states — to differentiate as today’s stem cells do and then dedifferentiate back to a less specialized form. The research implies that mechanisms of cellular differentiation predated the gradual rise of multicellular animals."