Sclera other species share, but also to the fact that the human iris is relatively small and comprises a significantly smaller portion of the exposed eye surface compared to other animals. It is theorized that this adaptation evolved because of our social nature as the eye became a useful communication tool in addition to a sensory organ. It is believed that the conspicuous sclera of the human eye makes it easier for one individual to infer where another individual is looking, increasing the efficacy of this particular form of nonverbal communication. Animal researchers have also found that, in the course of
Development of the human cerebral cortex in this area is where neurons, that are created in the ventricular zone, migrate through in order to reach the cortical plate. This zone is only present during corticogenesis and eventually transforms into adult white matter. The ventricular and subventricular zones exist below the intermediate zone and communicate to other zones through cell signalling, also creating neurons destined to migrate to other areas in the cortex. The marginal zone, along with the cortical zone, make up the 6 layers that form the cortex. This zone is the predecessor for layer 1 of the cortex. Astrocytes form an outer limiting membrane