http://www.sciencealert.com/in-a-remote-town-in-the-dominican-republic-some-girls-turn-into-boys In this remote village, some boys don’t grow a penis until they’re 12. Puberty can be an awkward time for anybody, but spare a thought for theGuevedoce children of the Dominican Republic, who literally appear to change their sex when they hit adolescence. As covered by Michael Mosley in the new BBC series, Countdown to Life: The Extraordinary Making of You, the remarkable case of theGuevedoces is a condition that affects just over 1 percent of the boys born in Salinas, a remote village lying in the southwest of the Dominican Republic. Guevedoces (literal translation “penis at 12”) - who are also called “machihembras”, meaning “first a woman, then a man" - appear to be completely female at birth and are brought up to be little girls. “When they’re born, they look like girls with no testes and what appears to be a vagina,” writes Mosley for The Telegraph. “It is only when they near puberty that the penis grows and testicles descend.” After the developments of puberty, Guevedoces grow up to be fully functional males in their society, although some telltale signs do give away their unique biological heritage.