Is knowledge also a belief?

My argumentation is an evolutionary biological (especially neurological) one, and I compare the phylogenetic evolution with the ontogenetic development. You can be sure that animals with a primitive (not complex enough) brain are not capable of distinguishing between “understanding” and “thinking something is true”. So you need to have a well enough working complex brain in order to distinguish between “understanding” and “thinking something is true”. The said roots are evolutionary biological (especially neurological) roots, mainly the nervous system that leads to a primitive brain that leads to a more complex brain that leads to a still more complex brain … and so on.