Seminar Two
Evolution of sexuality
The flehmen response
The flehmen response is a posture in which the mouth is held open, so that whiffs of sexual pheromones can reach the vomeronasal organ on the roof of the mouth. The vomeronasal sense is separate from the olfactory sense and the sensory organ sends separate neural tracts to the brain. Similar to smell (olfaction) but separate from smell, vomeronasal tracts help identify other animals close by and may also provide information about potential mates.
On the savannas of East Africa you will see male mammals sampling the air, and even a female’s urine on the ground, for evidence that a female is in heat. The vomeronasal organ is also used by other vertebrates, such as snakes, which sample the air with their forked tongues and move the tongue to the roof of their mouth.
