Why do homosexuals exist? Does homosexuality have any evolutionary advantage?

To know more:
Homosexuality throughout history: https://es.wikipedia.org/wiki/Homosex... #Homosexuality_a_lo_largo_de_la_historia
Kinsey Report: https://en.wikipedia.org/wiki/KinseyR...
Women with homosexual relatives are more fertile: http://journals.plos.org/plosone/arti...
Ni tolerance social intolerance affect proportion of homosexual people: http://journals.sagepub.com/doi/pdf/1...

Screenplay: Tonatiuh Moreno
Illustrations: Ruy Fernando Estrada, Sandra Cárdenas, Sergio Rivera
Voice: Javier Lacroix
Music: Mary Camarena and Jorge Verdín

Additional music:
Renaissance of Audionautix is ​​licensed the Creative Commons Attribution license (https://creativecommons.org/licenses/...)
Artista: http://audionautix.com/
Constancy Part 3 The Descent by Kevin MacLeod is licensed the Creative Commons Attribution license (https://creativecommons.org/licenses/...)
Source: http://incompetech.com/music/royalty...
Artist: http://incompetech.com/
Learning is Fun, Doug Maxwell
Baroque Cofee House