How do you locate fossil? It is possible to track them down in our by comparing our with the of another not too closely related species, such as the mouse for example. The rule is straightforward: if a is active in mice but not in humans, then it must be a fossil in humans. In this way, scientists have been able to show that the great majority of that are involved in perception in mammals are inactive in humans. These are the remains of a long gone era when our ancestors used chemical messages to communicate, as many animals still do today.
Have humans really become insensitive to? No. Not only do we transmit a few – in our saliva and other secretions – but we also react to them. So how do we perceive them? There are the remnants of a tiny organ inside our nose, which is at the heart of perception in many animals but seems to be inactive in humans. The problem remains unsolved.
The best known effect ofon humans is the synchronization of the menstrual cycles of women who are part of a community. also influence our social relationships. They are important in establishing the very first bonds between a mother and her newborn, and are known to stimulate the infant’s appetite when it is time to feed.