The Animals are yawn? Of course yes: you will surely have seen at least one dog or a Gatto open your mouth, tighten your eyes and emit sounds of pleasure when she wakes up (or when she is going to sleep). But How many animals yawn? The answer is: surprisingly many, to the point that there are examples of yawns in all groups of vertebrates. More: the Science of the yawn is increasingly studied, to the point that there are expert experts who only dedicate themselves to that. One of these is Andrew Gallup, head of the Gallup Lab of Johns Hopkins University, a research laboratory dedicated to yawns that has recently produced a study on the contagion of yawn in the cacatua.
Who gets rid of: from fish to mammals
Moment of passage. During his work, the Gallup Lab has shown that there are animals that yawn among the fish, the amphibians, i reptiles, the birds and mammals: all Vertibrati have this behavior, or rather, in all groups of vertebrates there are examples of yawns, or at least of gestures that look a lot like human yawns, and which consist in flooding the mouth and ironing the muscles of the skull.
And it is precisely this last detail that it could explain it Evolutionary purpose of the yawn. Open the mouth and do stretching of the cranio muscles increases the blood flow to the brain, and lets you enter arterial blood replacing that venous. In this way the Brain has, so to speak, a “blow of life”. Which works in both directions: it Rigiglio, according to this theory, would be the way they have animals to pass from one state to another, then from Vigil al rest and vice versa. A transition behavior, which was probably “invented” by fish and then remained in all the other groups of vertebrates.
Because it is contagious (and for whom)
Why is the yawn contagious? If the physiological function of the yawn is now more or less clear, much more mysterious is the fact that this behavior is contagious for many animals. The study mentioned on Cacatue Rosa is an exception in this sense, since it shows how the birds does not take place the contagion: as far as we know so far, the only volatile that suffers it is the wavy parrocchetto (the parrot commonly known as cocorita). In the same study, however, Gallup also warns against generalizations: the contagion of yawns between animals is a little studied topic, and almost always in social mammals.
Among which, in fact, it is yawn is a lot contagious, too between different species: it happens to us when we look at an animal that does it, but also works on the contrary – the Elephants, for example, can get infected by us, and, and a study of a few months ago shows that the chimpanzee get infected even by Anthropomorphic androids. But why does it happen? This is where our knowledge stops: it could be a classic imitation behavior that has no consequences but that “has remained” during the evolution, or the contagion could have deeper adaptive functions – perhaps a way to increase the Synchrony and ‘harmony of the group. The fact is that there is still a lot to discover on the yawn, and on his contrary powers.
