While almost all animals have some clustering of nerve cells that we could call a “brain,” the brain of humans is physiologically and functionally different from most, if not all, other animals. As mentioned earlier, it seems that only humans think about thinking, only humans introspect. Much of the brain is a read-write device. When knowledge is stored in a brain, it can be re-written, it can be added to and built on. Of course, it can also be forgotten, in which case that knowledge is lost. And the “wrong" knowledge can be loaded into the brain just as easily as the “right” knowledge.
An example of the difference between knowledge-in-DNA and knowledge-in-brains: all humans have an inbuilt capacity to learn a language. You don’t have to explicitly teach a small child to talk (though you may need to teach the child to talk “correctly” depending on what that means), you simply have to talk to him or her. The child will soak up the language in a quite predictable way. The knowledge of how to learn a language is passed down to the child from its parents in its DNA.
While the knowledge of how to learn a language is DNA-stored, the specific language is not—it is stored in the brain and needs to be learned. There does not appear to be any innate human language [1] and the language a child first learns depends mostly on who their parents are and where they are brought up.
Anthropologists have noted that the development of language was a pivotal step in in human evolution. It allowed the articulation of complex knowledge and its brain-to-brain transfer so that, when one individual learned something--some knowledge that was not or could not be encoded in DNA--that knowledge could then be passed on to others.
FOOTNOTES
[1] However, there are some reasonably universal sounds made by babies and children that have been adopted into many languages as signals to their caretakers. They are usually based on simple repeated consonants: MMM, BBB, PPP, DDD. Most language words for a mother use the “M” sound (mamma, ee-mah, ah-um) while for a father, who typically has less of a caretaking role, it varies more but is often the “P”, “D”, or “B” sound (pappa, dada, abba).