In article <loats1.749942282 at husc9>,
James Loats <loats1 at husc9.harvard.edu> wrote:
>>I am interest in knowing whether parthanogenesis has evolved in the male
>>sex of any species. I would presume not, for evolutionary reasons, but I
>>would like to know for sure. I would also like to know other peoples
>>opinions as to why this has not occured.
>>Well, my own opinion as to why this has/would not occur is more for
>physiological than "evolutionary" reasons: males don't do parthenogenesis
>because if they did, they'd be called females. My understanding is that
>"male" and "female" are defined in general by the relative motility of
>their gametes (i.e. "sperm/pollen" are motile, "eggs/ova" are not), and
>consequently, in those species which "give birth", by who bears the young
>or lays the egg.
Why couldn't a motile gamete parthenogeneses (as you say, verb form?).
The reason I presumed it never occured was that motile gametes don't have
the surrounding tissues (placenta, endosperm) for the developing emryo,
whether it is derived from parthogenesis or fertilization. I still don't
see any real reason you COULDN'T have parthenogenesis in males, just a
good explanation for why it is at least less common. So far I haven't
got any replies indicating that it does occur in ANY male of ANY species
on Earth.
>--
>Jim Loats * "I pass the test. I shall diminish,
>loats1 at husc.harvard.edu * and go into the West, and remain
>Bacterial Motor Works--the * Galadriel."
>Ultimate Swimming Machine! * -- J.R.R. Tolkien
--------------------------------------------------------------------------
John Reed
College of Forest Resources, AR-10
University of Washington
Seattle, WA 98195
Internet: johnreed at u.washington.edu
--------------------------------------------------------------------------
