From: Anders Sandberg (asa@nada.kth.se)
Date: Fri Nov 01 2002 - 01:34:45 MST
On Thu, Oct 31, 2002 at 11:07:03PM -0800, spike66 wrote:
>
> Question please, evolution wonks: since most
> mammals have multiple offspring and consequently
> have 4 pairs of nipples, are humans ever born with
> vestigial extra pairs of nipples? Does this
> phenomenon have a name? How common is it?
http://www.nlm.nih.gov/medlineplus/ency/article/003110.htm
Supernumerary nipples (also known as polymastia, pleomastia, polythelia
and accessory nipples) appear in around 5% of all children and are
usually single and smaller than real nipples. They are located along the
milk line as would be expected. They don't seem to lead to the
development of extra breasts, although extra breasts are possible but
very rare (http://www.smw.ch/oeil/1999/129-12-299-99.html). These states
are called ectopic - tissues are found elsewhere than they should, and
since they are the same kind of tissue as the original they can be
affected in the same way or cause problems in the same way. Extra
nipples can become sensitive due to the menstrual cycle, one can get
breast cancer in extra breasts and they may even secrete small amounts
of milk.
There is also a link to abnormalities in the urinary tract; a study from
Israel reported 40% of children with polythelia had obstructions or
duplications in the kidneys or the excretory system.
Extra breasts can appear elsewhere, so called mammae erraticae - the
buttock, back of neck, face, flank, upper arm, hip, shoulders, and
midline of the back and chest. This can even occur in men.
According to the above link (a great source) highest number of
supernumerary breasts, reported by Neugebauer in 1886, was eight
in addition to the two normal breasts.
Ah, the wonders of google and medicine!
At the entrance to the main KTH building where I sit there is a
sculptural fresco depicting among other things a mermaid with six or
eight nicely symmetric breasts. I couldn't find a good picture online,
unfortunately.
-- ----------------------------------------------------------------------- Anders Sandberg Towards Ascension! asa@nada.kth.se http://www.nada.kth.se/~asa/ GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y
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