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WillParkinson

(16,862 posts)
Thu Apr 17, 2014, 08:57 PM Apr 2014

Scientists discover insect female penis

http://www.theverge.com/2014/4/17/5617766/scientists-discover-insect-with-female-penis

Scientists have discovered four species of Brazilian insects in which the females possess a penis and the males possess a vagina. This announcement, made today in the journal Current Biology, represents the first documented instance of a "female penis" in the animal kingdom.

Contrary to popular belief, the presence or absence of certain sex organs isn't the determining factor when deciding which animal of a species is female and which is male. In fact, biologists don't use sex chromosomes either. They actually rely on the size of an animal's gametes — sperm in males and oocytes in females. As the rule goes, females are the sex that contribute the largest gametes, whereas males are the sex that contribute the smallest gametes and therefore expend the least amount of energy on producing these cells. So, in this particular instance of sex-role reversal, the convention still applies: the female in these species of insect produces the largest gametes — egg cells. She simply also happens to sport a penis that she introduces into the male's vagina during copulation.

("She simply also happens to sport a penis that she introduces in the male's vagina&quot
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Scientists discover insect female penis (Original Post) WillParkinson Apr 2014 OP
* Graphic Warning * rug Apr 2014 #1
Brazil Warren DeMontague Apr 2014 #2
It's time to question this garnete centered view of the sexes BainsBane Apr 2014 #3
Wow. 40 to 70 hour copulation! Where do I signup? (Warning: graphic insect 'xes' - that's sex ... DreamGypsy Apr 2014 #4

DreamGypsy

(2,252 posts)
4. Wow. 40 to 70 hour copulation! Where do I signup? (Warning: graphic insect 'xes' - that's sex ...
Thu Apr 17, 2014, 11:45 PM
Apr 2014

...reversed.)

Female Penis, Male Vagina, and Their Correlated Evolution in a Cave Insect:

Summary

Sex-specific elaborations are common in animals and have attracted the attention of many biologists, including Darwin [1]. It is accepted that sexual selection promotes the evolution of sex-specific elaborations. Due to the faster replenishment rate of gametes, males generally have higher potential reproductive and optimal mating rates than females. Therefore, sexual selection acts strongly on males [2], leading to the rapid evolution and diversification of male genitalia [3]. Male genitalia are sometimes used as devices for coercive holding of females as a result of sexual conflict over mating [4 and 5]. In contrast, female genitalia are usually simple. Here we report the reversal of intromittent organs in the insect genus Neotrogla (Psocodea: Prionoglarididae) from Brazilian caves. Females have a highly elaborate, penis-like structure, the gynosome, while males lack an intromittent organ. The gynosome has species-specific elaborations, such as numerous spines that fit species-specific pouches in the simple male genital chamber. During prolonged copulation (?40–70 hr), a large and potentially nutritious ejaculate is transferred from the male via the gynosome. The correlated genital evolution in Neotrogla is probably driven by reversed sexual selection with females competing for seminal gifts. Nothing similar is known among sex-role reversed animals.





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