Do rounded ears mean an evolutionary impasse?
It is a well-known fact that predators, and a lot of other mammals for which a keen sense of hearing is indispensable for staying alive, have pointed ears.
The ears of the primates, however, have „retrograded” during the course of evolution, and have become rounded. This is not, of course, the only factor facilitating the gradual blunting of our sense of hearing, although, according to certain researches, it surely has contributed to the process.
The memory of our once pointed ears can still be traced in our genes. A proof of this is, for example, the so-called Darwin-tubercle (Darwin’s Ear Point) discernible on the pinnae of a lot of people, which is the remainder of the point of the once beastlike ears.
Why are pointed ears more sensitive?
One of its reasons is rather simple: pointed ears focus sounds in a better way, which, in the case of animals, is supplemented by the fact that they can orientate themselves towards the source of sounds without turning their heads, by moving only their ears.
The other reason is the own frequency of the pinnae, as being solid objects themselves, which changes together with their shape. Pointed ears resonate with sounds at the frequency of around 8 kHz, thus they amplify sharp sounds instead of the intermediate frequencies. This is the reason why, amongst other things, dogs are sensitive to ultrasonic sounds, which are imperceptible for human ears.
Although turning the pinnae still remains impossible for human beings according to its anatomic features, the advantages of pointed ears can be enjoyed once again with the help of a simple, routine operation.
Be the next to sharpen your hearing!