Sexual selection has been curious with this species of insects discovered in Brazilian caves, since they represent the first example of an animal whose individuals have the genitalia of the opposite sex, that is, the female is the one with a penis and the male with the vagina. .
Why have most birds, which reproduce by internal fertilization (within the female) like humans, have lost their penis in the course of evolution? Scientists from the University of Florida (USA) have managed to solve the mystery by showing that, although during development the phallus of embryos of gallinaceous birds begins to grow, from a certain moment a gene called Bmp4 activates a process of programmed cell death.
As a study carried out by evolutionary biologists at the Australian National University has just shown, heterosexual women are more sexually attracted to men with large penises. Details are published in the journal 'Proceedings of the National Academy of Sciences' (PNAS).
A sea slug called 'Chromodoris reticulata', the size of a human thumb, has surprised scientists with its ability to shed its penis after mating to make it grow again later. The creature, which lives in the Pacific Ocean, is the first known that can repeatedly copulate with a "disposable penis," according to Japanese scientists from the University of Tokyo and Osaka City University in Biology Letters.
The Koro syndrome (original Javanese term meaning "turtle head") or Suk Yeong syndrome is a male psychiatric disorder, typical of China, India and Southeast Asia characterized by the unfounded conviction that the penis itself is shortening and entering the abdomen.
American scientists have managed to restore the erectile capacity of the penis in rats using adult stem cells from the intestine. The advance heralds a future new method for penile reconstruction in humans, especially in patients suffering from Peyronie's disease.
Danni Büchner is invited to Sam Dylan's Halloween party. But the "Goodbye Germany" emigrant has no desire for many other party guests. And find clear words.
