In many animals, the brain is located in a specific structure like the head, along with sensory organs and often together with the mouth.
However, there are distantly related animals which have a nervous system but no brain, like sea anemones and corals.
In a new paper, the sea anemone Nematostella vectensis was used to find out if one of the ends of the sea anemone corresponds to the head of higher animals. To do this the researchers studied the function of genes that control head development in higher animals during the embryonic development of the starlet sea anemone.