You do realize that asexual or intersexed species are not the same as homosexual right? Not to mention, oral sex is a construction of humans..so no one is "getting their dicks sucked".
But in both cases, they deviate from heterosexuality.
As far as evolution, in some cases either the male or female of the species was unfit to survive, and they had to evolve to form their own offspring.
You do realize that asexual or intersexed species are not the same as homosexual right? Not to mention, oral sex is a construction of humans..so no one is "getting their dicks sucked".
But in both cases, they deviate from heterosexuality.
As far as evolution, in some cases either the male or female of the species was unfit to survive, and they had to evolve to form their own offspring.