This is a difficult one. I grew up in a predominantly black environment, when we were also deemed working class. I also attended Pentecostal church on a regular basis. I don't know about the scientifics of what you're asking but I know I struggled for years to understand to what extent I was living a life that was both moral and right due to the overwhelming response and teachings of black christians on homosexuality and the initial presence of AIDS in the 1980s. From a biblical standpoint, the Bible is not as straightforward on this as some Christians and Historians would have us believe. It speaks about men copulating with beasts, it also speaks of the onslaught of Sodom, a place heavily populated with disease, alcoholism, prostitution, same-sex relationships etc. much like the world we live in, but it does not allude directly to homosexuality being an incorrect way of living. This is under the old covenant, but there are many who preach solely from the new covenant and use the old merely as a point of supporting their often diabolical viewpoints. This is where having a relationship with God descends into the farcical boxes we know as religion. God is love. God is accepting. If you believe that then you know that He will not walk away from you for loving someone helplessly, after all He does not promote unhappiness, we do.
As far as being necessary, if we are speaking about this in terms of reproduction - clearly not, if we are speaking about happiness, progress and social benefits - indubitably, yes.