Human ear variation

[Dr Jekyll]

Does the wide variation in the external size and shape of human ears correlate with hearing ability?

On the one hand you can argue that if it was relevant some 'best' ear shape would have evolved by now. But if it isn't why have such complicated shaped ears at all?

Could it be that there is some small variation in sensitivity to sounds from certain directions or certain frequencies? So if you have relatives with different ears from you they can detect danger you might have missed, thereby improving your chances of having offspring and passing on the genes for your ears to some and granddad's ears to others.

[anonymous-user]

Pardon?

[tapkaJohnD]

In fact, the widest variation is in the size and shape of the ear lobe, which apparently plays no part in hearing!
See: http://anatomyproartifex.blogspot.co.uk/2011/05/ex... for a wide range of examples of ears and lobes. No more variation then, than in the face.

And surely they have evolved to our advantage. Compare the shape of a chimpazee's external ear, much further from the side of the head than ours, but still the same basic shape. Gorillas are different, less elaborate. Maybe Gorilla evolution has got to the stage that if anyone wants to creep up on a Silverback and attack, well, let them try!

John

Edited by tapkaJohnD on Saturday 16th August 21:53

Edited by tapkaJohnD on Saturday 16th August 21:54

[steveT350C]

The external human ear, pinna, continues to grow in size throughout life to compensate for the slow loss of sensitivity of the middle and inner ear complexes.

[Simpo Two]

[quote=tapkaJohnD]In fact, the widest variation is in the size and shape of the ear lobe, which apparently plays no part in hearing![/footnote]

Which makes sense as it's not a survival function so can vary at random with no selection pressure.