Honus wrote:

TI On the cause of the mammalian descent of the testes (descensus
testiculorum).
AU FREY-R
SO ZEITSCHRIFT FUER ZOOLOGISCHE SYSTEMATIK UND EVOLUTIONSFORSCHUNG 29(1):
40-65
PY 1991
LS In Ger. with Ger. and Engl. summ.
AB Two explanations have been offered for the descent of the testes in
mammals,
both of which are frequently cited in the literature. MOORE and co-workers
argued that the phylogenetic rise of body temperature caused the
translocation
of the testes. According to PORTMANN, the descent of the testes was due to
the
evolution of the scrotum as a signal. However, both the sensibility of the
extra-abdominal testes to temperature elevations and the optical effects of
the
scrotum can be interpreted as a consequence of testicular descent rather
than
as its cause.


Years ago I reads an article equating temperature with fertility.
There was a huge difference between conception rates per capita when
comparing tropical climates to the northern regions.

If I remember correctly, there was roughly a four to one relationship.
An 'eskimo'(1) or Inuit would have an almost one hundred percent
chance of pregnancy per copulation, where the tropic dwellers would
have sex on the average of four or five times before pregnancy occurred.

The reference to body temperature plays into this. The scrotum is used
to regulate the temperature of it's contents, but his can only work
within certain set parameters. Climate can easily override the built
in mechanisms.

It makes sense when viewed in the perspective of food and climate.
It's a lot harder to survive in the far north, so courtship and
offspring have to be made in a careful and methodical manner.

The adventures of Cook and others in the South cover the other aspect.



mike








(1) politically incorrect


--
"The day Microsoft makes something that doesn't suck is
probably the day they start making vacuum cleaners."

Ernst Jan Plugge