[...] the first big question is why so many mammalian species evolved
hanging scrotal testicles to begin with. The male gonads in some
phylogenetic lineages went in completely different directions,
evolutionary speaking. For example, modern elephants' testicles
remain undescended and are deeply embedded in the body cavity (a
trait referred to as "testicond"), whereas other mammals, such as
seals, have descended testicles but are ascrotal, with the gonads
simply being subcutaneous.
Gallup and his coauthors jog through several possible theories of our
species' testicular evolution by descent.
<http://www.scientificamerican.com/blog/post.cfm?id=why-do-human-testicles-hang-like-th-2009-11-19>Link
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Posted By johannes to
<http://www.monochrom.at/english/2009/11/why-do-human-testicles-hang-like-that.htm>monochrom
at 11/22/2009 03:56:00 PM
