Discussion of everything related to the Theory of Evolution. 4
posts • Page 1 of 1 Every once in a while I have been wondering
what makes an itch so annoying you just have to scratch it (and
often it goes away after you have simply clawed it for a second
or two, quite unlike what happens with pain). Now I need you
guys to help me to figure out the evolutionary reasons behind
itching. To be more specific, I'm interested in "point itch",
that is, a hair tickles your face or an ant runs down your arm -
something local caused by an external factor. Persistent itching
in some general area (like your nose during the allergy season
or atopic dermatitis or dry skin etc. etc.) are not relevant,
because the reason for those is quite likely just a side effect
of the release of histamine and other such cellular mediators -
and in any case the etiology of the problem is entirely
different. But back to the original problem. Quite obviously
itching, unlike pain, is not a signal of acute tissue damage or
the risk of it. It i