Creatures are born , animate being reproduce , animate being die . In this three - tone program of sprightliness , that middle portion – to reproduce – is especially important . So , just like us humans , many creatures outstanding and small have developed elaborated , captivating , and oddly complex ways to do just this .
Few amount stranger than a handful of cave - dwelling insect from the tribeSensitibillini , including the species Afrotrogla and the Brazilian Neotrogla . Japanese scientist discoveredback in 2014 that the Neotrogla cave insect appeared to have reversed genital structure : the female person has a long penis - comparable Hammond organ while the male person has a vagina - same pouch .
After acquire anIg Nobel Prize in 2017 , the research worker are now back with some self-aggrandising insights into why these bat - poop eating animal have produce this “ evolutionary bauble ” .
Neotrogla indulges in 40- to 70 - hour - long sex activity sessions whereby the distaff mount the male , enter her member - like structure ( known as a gynosome ) into his vagina - corresponding genitalia . The female person ’s gynosome also Robert F. Curl round inside the male person and locks them together . Researchers have really tried to pull union couplet apart , only to snap the male ’s trunk in two piece because the connection is strong . Youch .
A hard ejection seat will form around the semen after the male injects sperm up the female ’s spermatozoan - storage organ . Since resources are so scarce here , the distaff can either apply the content of the capsule to fertilise her egg or she can also eat it for nutrition . Yum .
But what ’s the advantage of this irregular method acting of coupling ? As discussed in their new report in the journalBiology letter , it ’s something to do with the harsh life of live in a dark and ironic cave , as the distaff penis has evolved at least twice severally in this surroundings .
“ Evolution of a female penis is an inordinately rarified event , ” the study reads . “ Nevertheless , our results show that ithas arisen doubly in this small group of insects . ”
“ Because they dwell dry and oligotrophic caves , severe competition for seminal gifts has belike revoke their aptness for multiple conjugation ( vacate direction of sexual selection ) . ”
The female feature a tiny switching valve 0.3 - mm spacious at the entrance of the semen - storage organ , which can help them take in more semen . Writing in journaleLifelast month , the same squad of researchers speculate that " the ability to receive greater amount of semen thanks to the valve has led to ferocious competition over seed among females , facilitating the evolution of the distaff member . "
In other words , any resource – including sperm cell – is much sought after in the barren environment of the cave . Therefore , the females ca n’t just sit around and wait for the male person to make the move , they have adapted to become more aggressive , pro - active , and effective sperm - hunter .
